Refactors classes + bugfix + improves coverage (#2405)

* Uses classes prototype instead of their aliases

 - Class chart was moved to its own script.
 - Class AxisInternal was moved to its own script. It's only needed by Class Axis
 - Definition of Chart removed from core.js
 - Definition of AxisInternal removed from axis.js

* Replaces aliases of Class prototypes

  - Alias c3_chart_fn replaced by Chart.prototype where is due
  - Alias c3_chart_internal_fn replaced by ChartInternal.prototype where is due
  - spec/data.convets.js renamed to spec/data.convert-spec.js for clarity

* Fixes Chart.prototype.legend.hide behavior

 - It was calling $$.updateAndRedraw({withLegend: true});
 - It should call $$.updateAndRedraw({withLegend: false});

* loads *-helper.js and *-spec.js files

* adds tests to improve coverage

restores c3.js and c3.min.js to master version

fixes linter error

* util is a plain collection of functions

* adds test for api.x, drag and util

karma.conf.js

@@ -6,7 +6,7 @@ module.exports = function(config) {
     files: [
       'c3.css',
       'spec/*-helper.js',
-      'spec/*.js'
+      'spec/*-spec.js'
     ],
     preprocessors: {
       'spec/*.js': ['browserify']

spec/api.data-spec.js

@@ -44,13 +44,13 @@ describe('c3 api data', function () {
             });
         });
 
-        it('should return specifid data if string argument given', function () {
+        it('should return specified data if string argument given', function () {
             var results = chart.data('data1');
             expect(results.length).toBe(1);
             expect(results[0].id).toBe('data1');
         });
 
-        it('should return specifid data if array argument given', function () {
+        it('should return specified data if array argument given', function () {
             var results = chart.data(['data1', 'data2']);
             expect(results.length).toBe(2);
             expect(results[0].id).toBe('data1');
@@ -164,22 +164,124 @@ describe('c3 api data', function () {
 
 });
 
+describe('c3 api data.x', function () {
+    'use strict';
+
+    var chart;
+
+    var args = {
+        data: {
+            x: 'x',
+            columns: [
+                ['x', 10, 30, 45, 50, 70, 100],
+                ['data1', 30, 200, 100, 400, 150, 250],
+                ['data2', 20, 180, 240, 100, 190]
+            ]
+        }
+    };
+
+    beforeEach(function (done) {
+        chart = window.initChart(chart, args, done);
+    });
+
+    it('should return values for target data1', function () {
+        var values = chart.data.values('data1'),
+            expectedValues =   [30, 200, 100, 400, 150, 250];
+        expect(values.length).toBe(6);
+        values.forEach(function (v, i) {
+            expect(v).toBe(expectedValues[i]);
+        });
+    });
+
+    it('should return null when no args', function () {
+        var values = chart.data.values();
+        expect(values).toBeNull();
+    });
+
+    it('should return data values for  data if string argument given', function () {
+        var results = chart.data('data1');
+        expect(results.length).toBe(1);
+        expect(results[0].id).toBe('data1');
+    });
+
+    it('should return specified data if array argument given', function () {
+        var results = chart.data(['data1', 'data2']);
+        expect(results.length).toBe(2);
+        expect(results[0].id).toBe('data1');
+        expect(results[1].id).toBe('data2');
+    });
+
+});
+
+describe('c3 api data.xs', function () {
+    'use strict';
+
+    var chart;
+
+    var args = {
+        data: {
+            xs: {
+                'data1': 'x1',
+                'data2': 'x2',
+            },
+            columns: [
+                ['x1', 10, 30, 45, 50, 70, 100],
+                ['x2', 30, 50, 75, 100, 120],
+                ['data1', 30, 200, 100, 400, 150, 250],
+                ['data2', 20, 180, 240, 100, 190]
+            ]
+        }
+    };
+
+    beforeEach(function (done) {
+        chart = window.initChart(chart, args, done);
+    });
+
+    it('should return values for target data1', function () {
+        var values = chart.data.values('data1'),
+            expectedValues =   [30, 200, 100, 400, 150, 250];
+        expect(values.length).toBe(6);
+        values.forEach(function (v, i) {
+            expect(v).toBe(expectedValues[i]);
+        });
+    });
+
+    it('should return null when no args', function () {
+        var values = chart.data.values();
+        expect(values).toBeNull();
+    });
+
+    it('should return data values for  data if string argument given', function () {
+        var results = chart.data('data1');
+        expect(results.length).toBe(1);
+        expect(results[0].id).toBe('data1');
+    });
+
+    it('should return specified data if array argument given', function () {
+        var results = chart.data(['data1', 'data2']);
+        expect(results.length).toBe(2);
+        expect(results[0].id).toBe('data1');
+        expect(results[1].id).toBe('data2');
+    });
+
+});
+
 var customMatchers = {
-    toBeHexOrRGB: function(util, customEqualityTesters) {
+    toBeHexOrRGB: function (util, customEqualityTesters) {
         'use strict';
-        function rgb2hex(rgb){
+
+        function rgb2hex(rgb) {
             rgb = rgb.match(/^rgba?[\s+]?\([\s+]?(\d+)[\s+]?,[\s+]?(\d+)[\s+]?,[\s+]?(\d+)[\s+]?/i);
             return (rgb && rgb.length === 4) ? "#" +
-              ("0" + parseInt(rgb[1],10).toString(16)).slice(-2) +
-              ("0" + parseInt(rgb[2],10).toString(16)).slice(-2) +
-              ("0" + parseInt(rgb[3],10).toString(16)).slice(-2) : '';
+                ("0" + parseInt(rgb[1], 10).toString(16)).slice(-2) +
+                ("0" + parseInt(rgb[2], 10).toString(16)).slice(-2) +
+                ("0" + parseInt(rgb[3], 10).toString(16)).slice(-2) : '';
         }
 
-
         return {
-            compare: function(actual, expected){
+            compare: function (actual, expected) {
                 if (expected === undefined) {
-                  expected = '';
+                    expected = '';
                 }
 
                 var result = {};
@@ -190,11 +292,11 @@ var customMatchers = {
                 if (result.pass) {
                     result.message = "Expected " + actual + " not to be quite so goofy";
                 } else {
-                     result.message = "Expected " + actual + " to be goofy, but it was not very goofy";
+                    result.message = "Expected " + actual + " to be goofy, but it was not very goofy";
 
-                 }
+                }
 
-                 return result;
+                return result;
             }
         };
     }

spec/api.x-spec.js

@@ -0,0 +1,83 @@
+describe('c3 api.x', function () {
+    'use strict';
+
+    var chart;
+
+    var args = {
+        data: {
+            x: 'x',
+            columns: [
+                ['x', 10, 30, 45, 50, 70, 100],
+                ['data1', 30, 200, 100, 400, 150, 250],
+                ['data2', 20, 180, 240, 100, 190]
+            ]
+        }
+    };
+
+    beforeEach(function (done) {
+        chart = window.initChart(chart, args, done);
+    });
+
+    it('should return initial ticks for axis x', function () {
+        var expectedValues =   [10, 30, 45, 50, 70, 100];
+        d3.select('.c3-axis-x').selectAll('g.tick').each(function (d, i) {
+            var text = d3.select(this).select('text').text();
+            expect(+text).toBe(expectedValues[i]);
+        });
+    });
+
+    it('should return new ticks for axis x after calling chart.x', function () {
+        var expectedValues =   [16, 26, 55, 60, 75, 90];
+        chart.x(expectedValues);
+        d3.select('.c3-axis-x').selectAll('g.tick').each(function (d, i) {
+            var text = d3.select(this).select('text').text();
+            expect(+text).toBe(expectedValues[i]);
+        });
+    });
+});
+
+describe('c3 api.xs', function () {
+    'use strict';
+
+    var chart;
+
+    var args = {
+        data: {
+            xs: {
+                'data1': 'x1',
+                'data2': 'x2',
+            },
+            columns: [
+                ['x1', 10, 30, 50, 70, 90, 110],
+                ['x2', 20, 40, 60, 80, 100],
+                ['data1', 30, 200, 100, 400, 150, 250],
+                ['data2', 20, 180, 240, 100, 190]
+            ]
+        }
+    };
+
+    beforeEach(function (done) {
+        chart = window.initChart(chart, args, done);
+    });
+
+    it('should return initial ticks for axis x', function () {
+        var expectedValues =   ["10", "20", "30", "40", "50", "60", "70", "80", "90", "100", "110"];
+        d3.select('.c3-axis-x').selectAll('g.tick').each(function (d, i) {
+            var text = d3.select(this).select('text').text();
+            expect(text).toBe(expectedValues[i]);
+        });
+    });
+
+    it('should return new ticks for axis x after calling chart.xs', function () {
+        var expectedValues =    ["15", "25", "35", "45", "55", "65", "75", "85", "95", "105", "115"];
+        chart.xs({
+            data1: [15, 35, 55, 75, 95, 115],
+            data2: [25, 45, 65, 85, 105]
+        });
+        d3.select('.c3-axis-x').selectAll('g.tick').each(function (d, i) {
+            var text = d3.select(this).select('text').text();
+            expect(text).toBe(expectedValues[i]);
+        });
+    });
+
+});

spec/core-spec.js

@@ -28,11 +28,10 @@ describe('c3 chart', function () {
         });
 
         describe('should set 3rd party property to Function', function () {
-            beforeAll(function(){
+            beforeAll(function () {
                 Function.prototype.$extIsFunction = true;
             });
 
-
             it('should be created even if 3rd party property has been set', function () {
                 var svg = d3.select('#chart svg');
                 expect(svg).not.toBeNull();
@@ -60,10 +59,40 @@ describe('c3 chart', function () {
 
     });
 
+    describe('call resize and resized callbacks', function () {
+        beforeAll(function () {
+            args.bindto = '#chart';
+            args.axis = {
+                rotated: true
+            };
+            args.resize_var = false;
+            args.resized_var = false;
+
+            args.onresize = function () {
+                args.resize_var = true;
+            };
+            args.onresized = function () {
+                args.resized_var = true;
+            };
+
+        });
+
+        it('arbitrary parameters should be false before resize', function () {
+            expect(args.resize_var).toBe(false);
+            expect(args.resized_var).toBe(false);
+        });
+
+        it('arbitrary parameters should be true after resize', function () {
+            window.dispatchEvent(new Event('resize'));
+            expect(args.resize_var).toBe(true);
+            expect(args.resized_var).toBe(true);
+        });
+    });
+
     describe('bindto', function () {
 
         describe('selector', function () {
-            beforeAll(function(){
+            beforeAll(function () {
                 d3.select('#chart').html('');
                 args.bindto = '#chart';
             });
@@ -108,6 +137,19 @@ describe('c3 chart', function () {
                 expect(svg.size()).toBe(0);
             });
         });
+        describe('bind to selector with rotated axis', function () {
+            beforeAll(function () {
+                args.bindto = '#chart';
+                args.axis = {
+                    rotated: true
+                };
+            });
+
+            it('should be created', function () {
+                var svg = d3.select('#chart svg');
+                expect(svg.size()).toBe(1);
+            });
+        });
     });
 
     describe('empty data', function () {
@@ -128,7 +170,7 @@ describe('c3 chart', function () {
         });
 
         describe('more empty data', function () {
-            beforeAll(function(){
+            beforeAll(function () {
                 args = {
                     data: {
                         x: 'x',

spec/data-spec.js

@@ -1,3 +1,19 @@
+ describe('load without data', function () {
+
+    var chart, args;
+
+    beforeAll(function () {
+        args = {
+            data: {}
+        };
+    });
+
+    it('throws when data is an empty object', () => {
+        expect(() => window.initChart(chart, args))
+            .toThrowError(Error, /url or json or rows or columns is required/);
+    });        
+});
+
 describe('c3 chart data', function () {
     'use strict';
 
@@ -165,6 +181,37 @@ describe('c3 chart data', function () {
         });
     });
 
+    describe('load rows', function () {
+
+        beforeAll(function () {
+            args = {
+                data: {
+                    rows: [
+                      ['data1', 'data2', 'data3'],
+                      [90, 120, 300],
+                      [40, 160, 240],
+                      [50, 200, 290],
+                      [120, 160, 230],
+                      [80, 130, 300],
+                      [90, 220, 320]
+                    ]
+                }
+            };
+        });
+
+        it('should draw correctly', function () {
+            var expectedCx = [6, 124, 241,358,475,593],
+                expectedCy = [327, 391, 378,289,340,327];
+            d3.selectAll('.c3-circles-data1 .c3-circle').each(function (d, i) {
+                var circle = d3.select(this);
+                expect(+circle.attr('cx')).toBeCloseTo(expectedCx[i], 0);
+                expect(+circle.attr('cy')).toBeCloseTo(expectedCy[i], 0);
+            });
+        });
+    });
+
+
+
     describe('function in data.order', function () {
         beforeAll(function () {
             args = {

spec/drag-spec.js

@@ -0,0 +1,79 @@
+describe('drag behavior', function () {
+    'use strict';
+
+    var chart, shapes, $$, totalshapes;
+
+    var args = {
+        data: {
+            x: 'x',
+            columns: [
+                ['x', 10, 30, 45, 50, 70, 100],
+                ['data1', 30, 200, 100, 400, 150, 250],
+                ['data2', 20, 180, 240, 100, 190]
+            ],
+            selection: {
+                enabled: true,
+                grouped: true,
+                multiple: true,
+                draggable: true
+            },
+        }
+    };
+
+    beforeAll(function (done) {
+        chart = window.initChart(chart, args, done);
+        $$ = chart.internal;
+        shapes = $$.main.selectAll('.' + $$.CLASS.shapes)
+            .selectAll('.' + $$.CLASS.shape);
+        totalshapes = shapes.size();
+    });
+
+    it('should contain 15 shapes', function () {
+
+        expect(totalshapes).toBe(15);
+    });
+
+    it('should have no selected shapes', function () {
+
+        var selected = shapes
+            .filter(function () {
+                return d3.select(this).classed($$.CLASS.SELECTED);
+            }).size();
+
+        expect(selected).toBe(0);
+    });
+
+    describe('Trigger drag events', function () {
+
+        beforeAll(function () {
+            var s = chart.internal.eventRect,
+                coords1 = [(s.attr('width') - s.attr('x')) / 3, (s.attr('height') - s.attr('y')) / 3],
+                coords2 = [2 * (s.attr('width') - s.attr('x')) / 3, 2 * (s.attr('height') - s.attr('y')) / 3];
+            $$.dragstart(coords1);
+            $$.drag(coords2);
+            $$.dragend();
+        });
+
+        it('should select 6 shapes', function () {
+
+            var selected = shapes
+                .filter(function () {
+                    return d3.select(this).classed($$.CLASS.SELECTED);
+                }).size();
+
+            expect(selected).toBe(6);
+        });
+
+        it('should select 9 unselected shapes', function () {
+
+            var unselected = shapes
+                .filter(function () {
+                    return !d3.select(this).classed($$.CLASS.SELECTED);
+                }).size();
+
+            expect(unselected).toBe(9);
+        });
+
+    });
+
+});

spec/legend-spec.js

@@ -218,6 +218,38 @@ describe('c3 chart legend', function () {
 
     });
 
+    describe('with legend.show is true', function () {
+
+        beforeAll(function () {
+            args = {
+                data: {
+                    columns: [
+                        ['data1', 30, 200, 100, 400, 150, 250],
+                        ['data2', 130, 100, 200, 100, 250, 150]
+                    ]
+                },
+                legend: {
+                    show: true
+                }
+            };
+        });
+
+        it('should initially have rendered some legend items', function () {
+            expect(d3.selectAll('.c3-legend-item').empty()).toBe(false);
+        });
+
+        it('should remove rendered every legend items', function () {
+            chart.legend.hide();
+            d3.selectAll('.c3-legend-item').each(function () {
+                expect(d3.select(this).style('visibility')).toBe('hidden');
+                // This selects all the children, but we expect it to be empty
+                expect(d3.select(this).selectAll("*").length).toEqual(undefined);
+            });
+        });
+
+
+    });
+
     describe('custom legend size', function() {
         beforeAll(function () {
             args = {

spec/shape.bar-spec.js

@@ -7,6 +7,45 @@ describe('c3 chart shape bar', function () {
         chart = window.initChart(chart, args, done);
     });
 
+    describe('Path boxes', function () {
+        beforeAll(function () {
+            args = {
+                data: {
+                    columns: [
+                        ['data1', 30]
+                    ],
+                    type: 'bar',
+                },
+                bar: {
+                    width: {
+                        max: 40
+                    }
+                }
+            };
+        });
+
+        it('bars should have expected Path Box', function () {
+            var expected = {
+                x: 279,
+                y: 40,
+                width: 40,
+                height: 387
+            };
+
+            var shapes = chart.internal.main
+                .selectAll('.' + chart.internal.CLASS.shapes)
+                .selectAll('.' + chart.internal.CLASS.shape);
+            shapes.each(function () {
+                var pathBox = chart.internal.getPathBox(this);
+                expect(pathBox.x).toBeCloseTo(expected.x, -1);
+                expect(pathBox.y).toBeCloseTo(expected.y, -1);
+                expect(pathBox.width).toBeCloseTo(expected.width, -1);
+                expect(pathBox.height).toBeCloseTo(expected.height, -1);
+            });
+
+        });
+    });
+
     describe('with groups', function () {
 
         describe('with indexed data', function () {
@@ -30,7 +69,8 @@ describe('c3 chart shape bar', function () {
                     var rect = d3.select(this).node().getBoundingClientRect();
                     expect(rect.bottom).toBeCloseTo(expectedBottom[i], -1);
                 });
-           });
+            });
+
         });
 
         describe('with timeseries data', function () {
@@ -61,7 +101,7 @@ describe('c3 chart shape bar', function () {
                     var rect = d3.select(this).node().getBoundingClientRect();
                     expect(rect.bottom).toBeCloseTo(expectedBottom[i], -1);
                 });
-           });
+            });
         });
 
         describe('with category data', function () {
@@ -93,7 +133,7 @@ describe('c3 chart shape bar', function () {
                     var rect = d3.select(this).node().getBoundingClientRect();
                     expect(rect.bottom).toBeCloseTo(expectedBottom[i], -1);
                 });
-           });
+            });
         });
 
     });
@@ -164,23 +204,23 @@ describe('c3 chart shape bar', function () {
 
     });
 
-    describe('bar spacing', function() {
+    describe('bar spacing', function () {
 
-        var createArgs = function(spacing) {
+        var createArgs = function (spacing) {
             return {
                 size: {
-                  width: 500
+                    width: 500
                 },
                 data: {
                     columns: [
                         ['data1', 30, 200, 100],
                         ['data2', 50, 20, 10],
                         ['data3', 150, 120, 110],
-                        ['data4', 12, 24, 20 ]
+                        ['data4', 12, 24, 20]
                     ],
                     type: 'bar',
                     groups: [
-                        [ 'data1', 'data4' ]
+                        ['data1', 'data4']
                     ]
                 },
                 bar: {
@@ -189,27 +229,27 @@ describe('c3 chart shape bar', function () {
             };
         };
 
-        var getBBox = function(selector) {
-          return d3.select(selector).node().getBBox();
+        var getBBox = function (selector) {
+            return d3.select(selector).node().getBBox();
         };
 
-        var getBarContainerWidth = function() {
+        var getBarContainerWidth = function () {
             return parseInt(getBBox('.c3-chart-bars').width);
         };
 
-        var getBarContainerOffset = function() {
+        var getBarContainerOffset = function () {
             return parseInt(getBBox('.c3-chart-bars').x);
         };
 
-        var getBarBBox = function(name, idx) {
+        var getBarBBox = function (name, idx) {
             return getBBox('.c3-target-' + name + ' .c3-bar-' + (idx || 0));
         };
 
-        var getBarWidth = function(name, idx) {
-          return parseInt(getBarBBox(name, idx).width);
+        var getBarWidth = function (name, idx) {
+            return parseInt(getBarBBox(name, idx).width);
         };
 
-        var getBarOffset = function(name1, name2, idx) {
+        var getBarOffset = function (name1, name2, idx) {
             var bbox1 = getBarBBox(name1, idx);
             var bbox2 = getBarBBox(name2, idx);
             return parseInt(bbox2.x - (bbox1.x + bbox1.width));

spec/util-spec.js

@@ -0,0 +1,185 @@
+import {
+    asHalfPixel,
+    ceil10,
+    diffDomain,
+    getOption,
+    hasValue,
+    isArray,
+    isDefined,
+    isEmpty,
+    isFunction,
+    isString,
+    isUndefined,
+    isValue,
+    notEmpty,
+    sanitise
+} from '../src/util';
+
+describe('util.js tests', function () {
+    'use strict';
+
+    var undefined_var;
+    var html_str = '<div>Hello there</div>';
+    var html_entities_str = '&lt;div&gt;Hello there&lt;/div&gt;';
+    var empty_string = '';
+    var nonempty_string = 'hello there';
+    var nonempty_number = 1234.2;
+    var null_var = null;
+    var empty_object = {};
+    var nonempty_object = {
+        a: 1
+    };
+    var empty_array = [];
+    var nonempty_array = [1, 3];
+    var nonempty_function = function (a) {
+        return a;
+    };
+
+    describe('asHalfPixel, ceil10 and diffDomain functions', function () {
+
+        it('asHalfPixel should return correct value', function () {
+            expect(asHalfPixel(nonempty_number)).toBe(1235.5);
+        });
+        it('ceil10 should return correct value', function () {
+            expect(ceil10(nonempty_number)).toBe(1240);
+        });
+        it('diffDomain should return correct value', function () {
+            expect(diffDomain(nonempty_array)).toBe(2);
+        });
+
+    });
+
+    describe('getOption and hasValue functions', function () {
+
+        it('getOption should return value if options dict has specified key', function () {
+            expect(getOption(nonempty_object, 'a', 'b')).toBe(1);
+        });
+        it('getOption should return default value if options dict lacks specified key', function () {
+            expect(getOption(empty_object, 'a', 'b')).toBe('b');
+        });
+
+        it('hasValue should return true if dict has requested value', function () {
+            expect(hasValue(nonempty_object, 1)).toBe(true);
+        });
+        it('hasValue should return false if dict lacks requested value', function () {
+            expect(hasValue(nonempty_object, 2)).toBe(false);
+        });
+
+    });
+
+    describe('sanitise function', function () {
+
+        it('should replace < and > tags', function () {
+            expect(sanitise(html_str)).toBe(html_entities_str);
+        });
+
+        it('should not modify a string not containing  < and > tags', function () {
+            expect(sanitise(html_entities_str)).toBe(html_entities_str);
+        });
+
+        it('should not modify an imput whose type is not string', function () {
+            expect(sanitise(nonempty_number)).toBe(nonempty_number);
+        });
+    });
+
+    describe('isArray, isDefined, isEmpty, isFunction, isString, isUndefined, isValue and notEmpty functions', function () {
+
+        it('isArray should return true for array var', function () {
+            expect(isArray(nonempty_array)).toBe(true);
+        });
+        it('isDefined should return true for defined var', function () {
+            expect(isDefined(nonempty_string)).toBe(true);
+        });
+        it('isFunction should return true for function var', function () {
+            expect(isFunction(nonempty_function)).toBe(true);
+        });
+        it('isString should return true for string var', function () {
+            expect(isString(nonempty_string)).toBe(true);
+        });
+        it('isUndefined should return true for undefined var', function () {
+            expect(isUndefined(undefined_var)).toBe(true);
+        });
+        it('isValue should return true for value var', function () {
+            expect(isValue(nonempty_number)).toBe(1234.2);
+        });
+
+        it('isArray should return false for non array var', function () {
+            expect(isArray(nonempty_string)).toBe(false);
+        });
+        it('isDefined should return false for non defined var', function () {
+            expect(isDefined(undefined_var)).toBe(false);
+        });
+        it('isFunction should return false for non function var', function () {
+            expect(isFunction(nonempty_string)).toBe(false);
+        });
+        it('isString should return false for non string var', function () {
+            expect(isString(undefined_var)).toBe(false);
+        });
+        it('isUndefined should return false for non undefined var', function () {
+            expect(isUndefined(nonempty_string)).toBe(false);
+        });
+        it('isValue should return false for null var', function () {
+            expect(isValue(null_var)).toBe(false);
+        });
+
+        it('isEmpty should return false for nonempty_array', function () {
+            expect(isEmpty(nonempty_array)).toBe(false);
+        });
+        it('isEmpty should return false for nonempty_number', function () {
+            expect(isEmpty(nonempty_number)).toBe(false);
+        });
+        it('isEmpty should return false for nonempty_object', function () {
+            expect(isEmpty(nonempty_object)).toBe(false);
+        });
+        it('isEmpty should return false for nonempty_string', function () {
+            expect(isEmpty(nonempty_string)).toBe(false);
+        });
+
+        it('isEmpty should return true for empty_array', function () {
+            expect(isEmpty(empty_array)).toBe(true);
+        });
+        it('isEmpty should return true for empty_object', function () {
+            expect(isEmpty(empty_object)).toBe(true);
+        });
+        it('isEmpty should return true for empty_string', function () {
+            expect(isEmpty(empty_string)).toBe(true);
+        });
+        it('isEmpty should return true for null_var', function () {
+            expect(isEmpty(null_var)).toBe(true);
+        });
+        it('isEmpty should return true for undefined_var', function () {
+            expect(isEmpty(undefined_var)).toBe(true);
+        });
+
+        it('notEmpty should return false for empty_array', function () {
+            expect(notEmpty(empty_array)).toBe(false);
+        });
+        it('notEmpty should return false for empty_object', function () {
+            expect(notEmpty(empty_object)).toBe(false);
+        });
+        it('notEmpty should return false for empty_string', function () {
+            expect(notEmpty(empty_string)).toBe(false);
+        });
+        it('notEmpty should return false for null_var', function () {
+            expect(notEmpty(null_var)).toBe(false);
+        });
+        it('notEmpty should return false for undefined_var', function () {
+            expect(notEmpty(undefined_var)).toBe(false);
+        });
+
+        it('notEmpty should return true for nonempty_array', function () {
+            expect(notEmpty(nonempty_array)).toBe(true);
+        });
+        it('notEmpty should return true for nonempty_number', function () {
+            expect(notEmpty(nonempty_number)).toBe(true);
+        });
+        it('notEmpty should return true for nonempty_object', function () {
+            expect(notEmpty(nonempty_object)).toBe(true);
+        });
+        it('notEmpty should return true for nonempty_string', function () {
+            expect(notEmpty(nonempty_string)).toBe(true);
+        });
+
+    });
+
+});

src/api.axis.js

@@ -1,8 +1,8 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 import { isValue, isDefined } from './util';
 
-c3_chart_fn.axis = function () {};
-c3_chart_fn.axis.labels = function (labels) {
+Chart.prototype.axis = function () {};
+Chart.prototype.axis.labels = function (labels) {
     var $$ = this.internal;
     if (arguments.length) {
         Object.keys(labels).forEach(function (axisId) {
@@ -12,7 +12,7 @@ c3_chart_fn.axis.labels = function (labels) {
     }
     // TODO: return some values?
 };
-c3_chart_fn.axis.max = function (max) {
+Chart.prototype.axis.max = function (max) {
     var $$ = this.internal, config = $$.config;
     if (arguments.length) {
         if (typeof max === 'object') {
@@ -31,7 +31,7 @@ c3_chart_fn.axis.max = function (max) {
         };
     }
 };
-c3_chart_fn.axis.min = function (min) {
+Chart.prototype.axis.min = function (min) {
     var $$ = this.internal, config = $$.config;
     if (arguments.length) {
         if (typeof min === 'object') {
@@ -50,7 +50,7 @@ c3_chart_fn.axis.min = function (min) {
         };
     }
 };
-c3_chart_fn.axis.range = function (range) {
+Chart.prototype.axis.range = function (range) {
     if (arguments.length) {
         if (isDefined(range.max)) { this.axis.max(range.max); }
         if (isDefined(range.min)) { this.axis.min(range.min); }

src/api.category.js

@@ -1,6 +1,6 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.category = function (i, category) {
+Chart.prototype.category = function (i, category) {
     var $$ = this.internal, config = $$.config;
     if (arguments.length > 1) {
         config.axis_x_categories[i] = category;
@@ -8,7 +8,7 @@ c3_chart_fn.category = function (i, category) {
     }
     return config.axis_x_categories[i];
 };
-c3_chart_fn.categories = function (categories) {
+Chart.prototype.categories = function (categories) {
     var $$ = this.internal, config = $$.config;
     if (!arguments.length) { return config.axis_x_categories; }
     config.axis_x_categories = categories;

src/api.chart.js

@@ -1,18 +1,18 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.resize = function (size) {
+Chart.prototype.resize = function (size) {
     var $$ = this.internal, config = $$.config;
     config.size_width = size ? size.width : null;
     config.size_height = size ? size.height : null;
     this.flush();
 };
 
-c3_chart_fn.flush = function () {
+Chart.prototype.flush = function () {
     var $$ = this.internal;
     $$.updateAndRedraw({withLegend: true, withTransition: false, withTransitionForTransform: false});
 };
 
-c3_chart_fn.destroy = function () {
+Chart.prototype.destroy = function () {
     var $$ = this.internal;
 
     window.clearInterval($$.intervalForObserveInserted);

src/api.color.js

@@ -1,7 +1,7 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
 // TODO: fix
-c3_chart_fn.color = function (id) {
+Chart.prototype.color = function (id) {
     var $$ = this.internal;
     return $$.color(id); // more patterns
 };

src/api.data.js

@@ -1,15 +1,15 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.data = function (targetIds) {
+Chart.prototype.data = function (targetIds) {
     var targets = this.internal.data.targets;
     return typeof targetIds === 'undefined' ? targets : targets.filter(function (t) {
         return [].concat(targetIds).indexOf(t.id) >= 0;
     });
 };
-c3_chart_fn.data.shown = function (targetIds) {
+Chart.prototype.data.shown = function (targetIds) {
     return this.internal.filterTargetsToShow(this.data(targetIds));
 };
-c3_chart_fn.data.values = function (targetId) {
+Chart.prototype.data.values = function (targetId) {
     var targets, values = null;
     if (targetId) {
         targets = this.data(targetId);
@@ -17,13 +17,13 @@ c3_chart_fn.data.values = function (targetId) {
     }
     return values;
 };
-c3_chart_fn.data.names = function (names) {
+Chart.prototype.data.names = function (names) {
     this.internal.clearLegendItemTextBoxCache();
     return this.internal.updateDataAttributes('names', names);
 };
-c3_chart_fn.data.colors = function (colors) {
+Chart.prototype.data.colors = function (colors) {
     return this.internal.updateDataAttributes('colors', colors);
 };
-c3_chart_fn.data.axes = function (axes) {
+Chart.prototype.data.axes = function (axes) {
     return this.internal.updateDataAttributes('axes', axes);
 };

src/api.flow.js

@@ -1,8 +1,8 @@
 import CLASS from './class';
-import { c3_chart_fn, c3_chart_internal_fn } from './core';
+import { Chart, ChartInternal } from './core';
 import { isValue, isDefined, diffDomain } from './util';
 
-c3_chart_fn.flow = function (args) {
+Chart.prototype.flow = function (args) {
     var $$ = this.internal,
         targets, data, notfoundIds = [], orgDataCount = $$.getMaxDataCount(),
         dataCount, domain, baseTarget, baseValue, length = 0, tail = 0, diff, to;
@@ -145,7 +145,7 @@ c3_chart_fn.flow = function (args) {
     });
 };
 
-c3_chart_internal_fn.generateFlow = function (args) {
+ChartInternal.prototype.generateFlow = function (args) {
     var $$ = this, config = $$.config, d3 = $$.d3;
 
     return function () {

src/api.focus.js

@@ -1,7 +1,7 @@
 import CLASS from './class';
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.focus = function (targetIds) {
+Chart.prototype.focus = function (targetIds) {
     var $$ = this.internal, candidates;
 
     targetIds = $$.mapToTargetIds(targetIds);
@@ -21,7 +21,7 @@ c3_chart_fn.focus = function (targetIds) {
     });
 };
 
-c3_chart_fn.defocus = function (targetIds) {
+Chart.prototype.defocus = function (targetIds) {
     var $$ = this.internal, candidates;
 
     targetIds = $$.mapToTargetIds(targetIds);
@@ -39,7 +39,7 @@ c3_chart_fn.defocus = function (targetIds) {
     $$.defocusedTargetIds = targetIds;
 };
 
-c3_chart_fn.revert = function (targetIds) {
+Chart.prototype.revert = function (targetIds) {
     var $$ = this.internal, candidates;
 
     targetIds = $$.mapToTargetIds(targetIds);

src/api.grid.js

@@ -1,33 +1,33 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.xgrids = function (grids) {
+Chart.prototype.xgrids = function (grids) {
     var $$ = this.internal, config = $$.config;
     if (! grids) { return config.grid_x_lines; }
     config.grid_x_lines = grids;
     $$.redrawWithoutRescale();
     return config.grid_x_lines;
 };
-c3_chart_fn.xgrids.add = function (grids) {
+Chart.prototype.xgrids.add = function (grids) {
     var $$ = this.internal;
     return this.xgrids($$.config.grid_x_lines.concat(grids ? grids : []));
 };
-c3_chart_fn.xgrids.remove = function (params) { // TODO: multiple
+Chart.prototype.xgrids.remove = function (params) { // TODO: multiple
     var $$ = this.internal;
     $$.removeGridLines(params, true);
 };
 
-c3_chart_fn.ygrids = function (grids) {
+Chart.prototype.ygrids = function (grids) {
     var $$ = this.internal, config = $$.config;
     if (! grids) { return config.grid_y_lines; }
     config.grid_y_lines = grids;
     $$.redrawWithoutRescale();
     return config.grid_y_lines;
 };
-c3_chart_fn.ygrids.add = function (grids) {
+Chart.prototype.ygrids.add = function (grids) {
     var $$ = this.internal;
     return this.ygrids($$.config.grid_y_lines.concat(grids ? grids : []));
 };
-c3_chart_fn.ygrids.remove = function (params) { // TODO: multiple
+Chart.prototype.ygrids.remove = function (params) { // TODO: multiple
     var $$ = this.internal;
     $$.removeGridLines(params, false);
 };

src/api.group.js

@@ -1,7 +1,7 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 import { isUndefined } from './util';
 
-c3_chart_fn.groups = function (groups) {
+Chart.prototype.groups = function (groups) {
     var $$ = this.internal, config = $$.config;
     if (isUndefined(groups)) { return config.data_groups; }
     config.data_groups = groups;

src/api.legend.js

@@ -1,13 +1,13 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.legend = function () {};
-c3_chart_fn.legend.show = function (targetIds) {
+Chart.prototype.legend = function () {};
+Chart.prototype.legend.show = function (targetIds) {
     var $$ = this.internal;
     $$.showLegend($$.mapToTargetIds(targetIds));
     $$.updateAndRedraw({withLegend: true});
 };
-c3_chart_fn.legend.hide = function (targetIds) {
+Chart.prototype.legend.hide = function (targetIds) {
     var $$ = this.internal;
     $$.hideLegend($$.mapToTargetIds(targetIds));
-    $$.updateAndRedraw({withLegend: true});
+    $$.updateAndRedraw({withLegend: false});
 };

src/api.load.js

@@ -1,6 +1,6 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.load = function (args) {
+Chart.prototype.load = function (args) {
     var $$ = this.internal, config = $$.config;
     // update xs if specified
     if (args.xs) {
@@ -8,7 +8,7 @@ c3_chart_fn.load = function (args) {
     }
     // update names if exists
     if ('names' in args) {
-        c3_chart_fn.data.names.bind(this)(args.names);
+        Chart.prototype.data.names.bind(this)(args.names);
     }
     // update classes if exists
     if ('classes' in args) {
@@ -48,7 +48,7 @@ c3_chart_fn.load = function (args) {
     }
 };
 
-c3_chart_fn.unload = function (args) {
+Chart.prototype.unload = function (args) {
     var $$ = this.internal;
     args = args || {};
     if (args instanceof Array) {

src/api.region.js

@@ -1,21 +1,21 @@
 import CLASS from './class';
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.regions = function (regions) {
+Chart.prototype.regions = function (regions) {
     var $$ = this.internal, config = $$.config;
     if (!regions) { return config.regions; }
     config.regions = regions;
     $$.redrawWithoutRescale();
     return config.regions;
 };
-c3_chart_fn.regions.add = function (regions) {
+Chart.prototype.regions.add = function (regions) {
     var $$ = this.internal, config = $$.config;
     if (!regions) { return config.regions; }
     config.regions = config.regions.concat(regions);
     $$.redrawWithoutRescale();
     return config.regions;
 };
-c3_chart_fn.regions.remove = function (options) {
+Chart.prototype.regions.remove = function (options) {
     var $$ = this.internal, config = $$.config,
         duration, classes, regions;
 

src/api.selection.js

@@ -1,8 +1,8 @@
 import CLASS from './class';
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 import { isDefined } from './util';
 
-c3_chart_fn.selected = function (targetId) {
+Chart.prototype.selected = function (targetId) {
     var $$ = this.internal, d3 = $$.d3;
     return d3.merge(
         $$.main.selectAll('.' + CLASS.shapes + $$.getTargetSelectorSuffix(targetId)).selectAll('.' + CLASS.shape)
@@ -10,7 +10,7 @@ c3_chart_fn.selected = function (targetId) {
             .map(function (d) { return d.map(function (d) { var data = d.__data__; return data.data ? data.data : data; }); })
     );
 };
-c3_chart_fn.select = function (ids, indices, resetOther) {
+Chart.prototype.select = function (ids, indices, resetOther) {
     var $$ = this.internal, d3 = $$.d3, config = $$.config;
     if (! config.data_selection_enabled) { return; }
     $$.main.selectAll('.' + CLASS.shapes).selectAll('.' + CLASS.shape).each(function (d, i) {
@@ -34,7 +34,7 @@ c3_chart_fn.select = function (ids, indices, resetOther) {
         }
     });
 };
-c3_chart_fn.unselect = function (ids, indices) {
+Chart.prototype.unselect = function (ids, indices) {
     var $$ = this.internal, d3 = $$.d3, config = $$.config;
     if (! config.data_selection_enabled) { return; }
     $$.main.selectAll('.' + CLASS.shapes).selectAll('.' + CLASS.shape).each(function (d, i) {

src/api.show.js

@@ -1,6 +1,6 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.show = function (targetIds, options) {
+Chart.prototype.show = function (targetIds, options) {
     var $$ = this.internal, targets;
 
     targetIds = $$.mapToTargetIds(targetIds);
@@ -23,7 +23,7 @@ c3_chart_fn.show = function (targetIds, options) {
     $$.redraw({withUpdateOrgXDomain: true, withUpdateXDomain: true, withLegend: true});
 };
 
-c3_chart_fn.hide = function (targetIds, options) {
+Chart.prototype.hide = function (targetIds, options) {
     var $$ = this.internal, targets;
 
     targetIds = $$.mapToTargetIds(targetIds);
@@ -46,7 +46,7 @@ c3_chart_fn.hide = function (targetIds, options) {
     $$.redraw({withUpdateOrgXDomain: true, withUpdateXDomain: true, withLegend: true});
 };
 
-c3_chart_fn.toggle = function (targetIds, options) {
+Chart.prototype.toggle = function (targetIds, options) {
     var that = this, $$ = this.internal;
     $$.mapToTargetIds(targetIds).forEach(function (targetId) {
         $$.isTargetToShow(targetId) ? that.hide(targetId, options) : that.show(targetId, options);

src/api.tooltip.js

@@ -1,7 +1,7 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.tooltip = function () {};
-c3_chart_fn.tooltip.show = function (args) {
+Chart.prototype.tooltip = function () {};
+Chart.prototype.tooltip.show = function (args) {
     var $$ = this.internal, targets, data, mouse = {};
 
     // determine mouse position on the chart
@@ -29,7 +29,7 @@ c3_chart_fn.tooltip.show = function (args) {
 
     $$.config.tooltip_onshow.call($$, data);
 };
-c3_chart_fn.tooltip.hide = function () {
+Chart.prototype.tooltip.hide = function () {
     // TODO: get target data by checking the state of focus
     this.internal.dispatchEvent('mouseout', 0);
 

src/api.transform.js

@@ -1,12 +1,12 @@
-import { c3_chart_fn, c3_chart_internal_fn } from './core';
+import { Chart, ChartInternal } from './core';
 
-c3_chart_fn.transform = function (type, targetIds) {
+Chart.prototype.transform = function (type, targetIds) {
     var $$ = this.internal,
         options = ['pie', 'donut'].indexOf(type) >= 0 ? {withTransform: true} : null;
     $$.transformTo(targetIds, type, options);
 };
 
-c3_chart_internal_fn.transformTo = function (targetIds, type, optionsForRedraw) {
+ChartInternal.prototype.transformTo = function (targetIds, type, optionsForRedraw) {
     var $$ = this,
         withTransitionForAxis = !$$.hasArcType(),
         options = optionsForRedraw || {withTransitionForAxis: withTransitionForAxis};

src/api.x.js

@@ -1,6 +1,6 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 
-c3_chart_fn.x = function (x) {
+Chart.prototype.x = function (x) {
     var $$ = this.internal;
     if (arguments.length) {
         $$.updateTargetX($$.data.targets, x);
@@ -8,7 +8,7 @@ c3_chart_fn.x = function (x) {
     }
     return $$.data.xs;
 };
-c3_chart_fn.xs = function (xs) {
+Chart.prototype.xs = function (xs) {
     var $$ = this.internal;
     if (arguments.length) {
         $$.updateTargetXs($$.data.targets, xs);

src/api.zoom.js

@@ -1,7 +1,7 @@
-import { c3_chart_fn } from './core';
+import { Chart } from './core';
 import { isDefined } from './util';
 
-c3_chart_fn.zoom = function (domain) {
+Chart.prototype.zoom = function (domain) {
     var $$ = this.internal;
     if (domain) {
         if ($$.isTimeSeries()) {
@@ -20,12 +20,12 @@ c3_chart_fn.zoom = function (domain) {
         return $$.x.domain();
     }
 };
-c3_chart_fn.zoom.enable = function (enabled) {
+Chart.prototype.zoom.enable = function (enabled) {
     var $$ = this.internal;
     $$.config.zoom_enabled = enabled;
     $$.updateAndRedraw();
 };
-c3_chart_fn.unzoom = function () {
+Chart.prototype.unzoom = function () {
     var $$ = this.internal;
     if ($$.config.subchart_show) {
         $$.brush.clear();
@@ -36,7 +36,7 @@ c3_chart_fn.unzoom = function () {
     }
 };
 
-c3_chart_fn.zoom.max = function (max) {
+Chart.prototype.zoom.max = function (max) {
     var $$ = this.internal, config = $$.config, d3 = $$.d3;
     if (max === 0 || max) {
         config.zoom_x_max = d3.max([$$.orgXDomain[1], max]);
@@ -46,7 +46,7 @@ c3_chart_fn.zoom.max = function (max) {
     }
 };
 
-c3_chart_fn.zoom.min = function (min) {
+Chart.prototype.zoom.min = function (min) {
     var $$ = this.internal, config = $$.config, d3 = $$.d3;
     if (min === 0 || min) {
         config.zoom_x_min = d3.min([$$.orgXDomain[0], min]);
@@ -56,7 +56,7 @@ c3_chart_fn.zoom.min = function (min) {
     }
 };
 
-c3_chart_fn.zoom.range = function (range) {
+Chart.prototype.zoom.range = function (range) {
     if (arguments.length) {
         if (isDefined(range.max)) { this.domain.max(range.max); }
         if (isDefined(range.min)) { this.domain.min(range.min); }

src/arc.js

@@ -1,8 +1,8 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isFunction } from './util';
 
-c3_chart_internal_fn.initPie = function () {
+ChartInternal.prototype.initPie = function () {
     var $$ = this, d3 = $$.d3;
     $$.pie = d3.pie().value(function (d) {
         return d.values.reduce(function (a, b) { return a + b.value; }, 0);
@@ -19,7 +19,7 @@ c3_chart_internal_fn.initPie = function () {
     $$.pie.sort(orderFct || null);
 };
 
-c3_chart_internal_fn.updateRadius = function () {
+ChartInternal.prototype.updateRadius = function () {
     var $$ = this, config = $$.config,
         w = config.gauge_width || config.donut_width,
         gaugeArcWidth = $$.filterTargetsToShow($$.data.targets).length * $$.config.gauge_arcs_minWidth;
@@ -30,14 +30,14 @@ c3_chart_internal_fn.updateRadius = function () {
     $$.gaugeArcWidth = w ? w : (gaugeArcWidth <= $$.radius - $$.innerRadius ? $$.radius - $$.innerRadius : (gaugeArcWidth <= $$.radius ? gaugeArcWidth : $$.radius));
 };
 
-c3_chart_internal_fn.updateArc = function () {
+ChartInternal.prototype.updateArc = function () {
     var $$ = this;
     $$.svgArc = $$.getSvgArc();
     $$.svgArcExpanded = $$.getSvgArcExpanded();
     $$.svgArcExpandedSub = $$.getSvgArcExpanded(0.98);
 };
 
-c3_chart_internal_fn.updateAngle = function (d) {
+ChartInternal.prototype.updateAngle = function (d) {
     var $$ = this, config = $$.config,
         found = false, index = 0,
         gMin, gMax, gTic, gValue;
@@ -71,7 +71,7 @@ c3_chart_internal_fn.updateAngle = function (d) {
     return found ? d : null;
 };
 
-c3_chart_internal_fn.getSvgArc = function () {
+ChartInternal.prototype.getSvgArc = function () {
     var $$ = this, hasGaugeType = $$.hasType('gauge'),
         singleArcWidth = $$.gaugeArcWidth / $$.filterTargetsToShow($$.data.targets).length,
         arc = $$.d3.arc().outerRadius(function(d) {
@@ -90,7 +90,7 @@ c3_chart_internal_fn.getSvgArc = function () {
     return newArc;
 };
 
-c3_chart_internal_fn.getSvgArcExpanded = function (rate) {
+ChartInternal.prototype.getSvgArcExpanded = function (rate) {
     rate = rate || 1;
     var $$ = this, hasGaugeType = $$.hasType('gauge'),
         singleArcWidth = $$.gaugeArcWidth / $$.filterTargetsToShow($$.data.targets).length,
@@ -106,12 +106,12 @@ c3_chart_internal_fn.getSvgArcExpanded = function (rate) {
     };
 };
 
-c3_chart_internal_fn.getArc = function (d, withoutUpdate, force) {
+ChartInternal.prototype.getArc = function (d, withoutUpdate, force) {
     return force || this.isArcType(d.data) ? this.svgArc(d, withoutUpdate) : "M 0 0";
 };
 
 
-c3_chart_internal_fn.transformForArcLabel = function (d) {
+ChartInternal.prototype.transformForArcLabel = function (d) {
     var $$ = this, config = $$.config,
         updated = $$.updateAngle(d), c, x, y, h, ratio, translate = "", hasGauge = $$.hasType('gauge');
     if (updated && !hasGauge) {
@@ -137,14 +137,14 @@ c3_chart_internal_fn.transformForArcLabel = function (d) {
     return translate;
 };
 
-c3_chart_internal_fn.getArcRatio = function (d) {
+ChartInternal.prototype.getArcRatio = function (d) {
     var $$ = this,
         config = $$.config,
         whole = Math.PI * ($$.hasType('gauge') && !config.gauge_fullCircle ? 1 : 2);
     return d ? (d.endAngle - d.startAngle) / whole : null;
 };
 
-c3_chart_internal_fn.convertToArcData = function (d) {
+ChartInternal.prototype.convertToArcData = function (d) {
     return this.addName({
         id: d.data.id,
         value: d.value,
@@ -153,7 +153,7 @@ c3_chart_internal_fn.convertToArcData = function (d) {
     });
 };
 
-c3_chart_internal_fn.textForArcLabel = function (d) {
+ChartInternal.prototype.textForArcLabel = function (d) {
     var $$ = this,
         updated, value, ratio, id, format;
     if (! $$.shouldShowArcLabel()) { return ""; }
@@ -166,14 +166,14 @@ c3_chart_internal_fn.textForArcLabel = function (d) {
     return format ? format(value, ratio, id) : $$.defaultArcValueFormat(value, ratio);
 };
 
-c3_chart_internal_fn.textForGaugeMinMax = function (value, isMax) {
+ChartInternal.prototype.textForGaugeMinMax = function (value, isMax) {
     var $$ = this,
         format = $$.getGaugeLabelExtents();
 
     return format ? format(value, isMax) : value;
 };
 
-c3_chart_internal_fn.expandArc = function (targetIds) {
+ChartInternal.prototype.expandArc = function (targetIds) {
     var $$ = this, interval;
 
     // MEMO: avoid to cancel transition
@@ -206,7 +206,7 @@ c3_chart_internal_fn.expandArc = function (targetIds) {
     });
 };
 
-c3_chart_internal_fn.unexpandArc = function (targetIds) {
+ChartInternal.prototype.unexpandArc = function (targetIds) {
     var $$ = this;
 
     if ($$.transiting) { return; }
@@ -221,7 +221,7 @@ c3_chart_internal_fn.unexpandArc = function (targetIds) {
     $$.svg.selectAll('.' + CLASS.arc);
 };
 
-c3_chart_internal_fn.expandDuration = function (id) {
+ChartInternal.prototype.expandDuration = function (id) {
     var $$ = this, config = $$.config;
 
     if ($$.isDonutType(id)) {
@@ -236,14 +236,14 @@ c3_chart_internal_fn.expandDuration = function (id) {
 
 };
 
-c3_chart_internal_fn.shouldExpand = function (id) {
+ChartInternal.prototype.shouldExpand = function (id) {
     var $$ = this, config = $$.config;
     return ($$.isDonutType(id) && config.donut_expand) ||
            ($$.isGaugeType(id) && config.gauge_expand) ||
            ($$.isPieType(id) && config.pie_expand);
 };
 
-c3_chart_internal_fn.shouldShowArcLabel = function () {
+ChartInternal.prototype.shouldShowArcLabel = function () {
     var $$ = this, config = $$.config, shouldShow = true;
     if ($$.hasType('donut')) {
         shouldShow = config.donut_label_show;
@@ -254,13 +254,13 @@ c3_chart_internal_fn.shouldShowArcLabel = function () {
     return shouldShow;
 };
 
-c3_chart_internal_fn.meetsArcLabelThreshold = function (ratio) {
+ChartInternal.prototype.meetsArcLabelThreshold = function (ratio) {
     var $$ = this, config = $$.config,
         threshold = $$.hasType('donut') ? config.donut_label_threshold : config.pie_label_threshold;
     return ratio >= threshold;
 };
 
-c3_chart_internal_fn.getArcLabelFormat = function () {
+ChartInternal.prototype.getArcLabelFormat = function () {
     var $$ = this, config = $$.config,
         format = config.pie_label_format;
     if ($$.hasType('gauge')) {
@@ -271,17 +271,17 @@ c3_chart_internal_fn.getArcLabelFormat = function () {
     return format;
 };
 
-c3_chart_internal_fn.getGaugeLabelExtents = function () {
+ChartInternal.prototype.getGaugeLabelExtents = function () {
     var $$ = this, config = $$.config;
     return config.gauge_label_extents;
 };
 
-c3_chart_internal_fn.getArcTitle = function () {
+ChartInternal.prototype.getArcTitle = function () {
     var $$ = this;
     return $$.hasType('donut') ? $$.config.donut_title : "";
 };
 
-c3_chart_internal_fn.updateTargetsForArc = function (targets) {
+ChartInternal.prototype.updateTargetsForArc = function (targets) {
     var $$ = this, main = $$.main,
         mainPies, mainPieEnter,
         classChartArc = $$.classChartArc.bind($$),
@@ -303,7 +303,7 @@ c3_chart_internal_fn.updateTargetsForArc = function (targets) {
     //mainPieUpdate.exit().remove();
 };
 
-c3_chart_internal_fn.initArc = function () {
+ChartInternal.prototype.initArc = function () {
     var $$ = this;
     $$.arcs = $$.main.select('.' + CLASS.chart).append("g")
         .attr("class", CLASS.chartArcs)
@@ -314,7 +314,7 @@ c3_chart_internal_fn.initArc = function () {
         .text($$.getArcTitle());
 };
 
-c3_chart_internal_fn.redrawArc = function (duration, durationForExit, withTransform) {
+ChartInternal.prototype.redrawArc = function (duration, durationForExit, withTransform) {
     var $$ = this, d3 = $$.d3, config = $$.config, main = $$.main,
         arcs, mainArc, backgroundArc,
 	arcLabelLines, mainArcLabelLine,
@@ -499,7 +499,7 @@ c3_chart_internal_fn.redrawArc = function (duration, durationForExit, withTransf
             .text(config.gauge_label_show ? $$.textForGaugeMinMax(config.gauge_max, true) : '');
     }
 };
-c3_chart_internal_fn.initGauge = function () {
+ChartInternal.prototype.initGauge = function () {
     var arcs = this.arcs;
     if (this.hasType('gauge')) {
         arcs.append('g')
@@ -518,6 +518,6 @@ c3_chart_internal_fn.initGauge = function () {
             .style("pointer-events", "none");
     }
 };
-c3_chart_internal_fn.getGaugeLabelHeight = function () {
+ChartInternal.prototype.getGaugeLabelHeight = function () {
     return this.config.gauge_label_show ? 20 : 0;
 };

src/axis-internal.js

@@ -0,0 +1,390 @@
+function AxisInternal(component, params) {
+    var internal = this;
+    internal.component = component;
+    internal.params = params || {};
+
+    internal.d3 = component.d3;
+    internal.scale = internal.d3.scaleLinear();
+    internal.range;
+    internal.orient = "bottom";
+    internal.innerTickSize = 6;
+    internal.outerTickSize = this.params.withOuterTick ? 6 : 0;
+    internal.tickPadding = 3;
+    internal.tickValues = null;
+    internal.tickFormat;
+    internal.tickArguments;
+
+    internal.tickOffset = 0;
+    internal.tickCulling = true;
+    internal.tickCentered;
+    internal.tickTextCharSize;
+    internal.tickTextRotate = internal.params.tickTextRotate;
+    internal.tickLength;
+
+    internal.axis = internal.generateAxis();
+}
+
+AxisInternal.prototype.axisX = function (selection, x, tickOffset) {
+    selection.attr("transform", function (d) {
+        return "translate(" + Math.ceil(x(d) + tickOffset) + ", 0)";
+    });
+};
+AxisInternal.prototype.axisY = function (selection, y) {
+    selection.attr("transform", function (d) {
+        return "translate(0," + Math.ceil(y(d)) + ")";
+    });
+};
+AxisInternal.prototype.scaleExtent = function (domain) {
+    var start = domain[0], stop = domain[domain.length - 1];
+    return start < stop ? [ start, stop ] : [ stop, start ];
+};
+AxisInternal.prototype.generateTicks = function (scale) {
+    var internal = this;
+    var i, domain, ticks = [];
+    if (scale.ticks) {
+        return scale.ticks.apply(scale, internal.tickArguments);
+    }
+    domain = scale.domain();
+    for (i = Math.ceil(domain[0]); i < domain[1]; i++) {
+        ticks.push(i);
+    }
+    if (ticks.length > 0 && ticks[0] > 0) {
+        ticks.unshift(ticks[0] - (ticks[1] - ticks[0]));
+    }
+    return ticks;
+};
+AxisInternal.prototype.copyScale = function () {
+    var internal = this;
+    var newScale = internal.scale.copy(), domain;
+    if (internal.params.isCategory) {
+        domain = internal.scale.domain();
+        newScale.domain([domain[0], domain[1] - 1]);
+    }
+    return newScale;
+};
+AxisInternal.prototype.textFormatted = function (v) {
+    var internal = this,
+        formatted = internal.tickFormat ? internal.tickFormat(v) : v;
+    return typeof formatted !== 'undefined' ? formatted : '';
+};
+AxisInternal.prototype.updateRange = function () {
+    var internal = this;
+    internal.range = internal.scale.rangeExtent ? internal.scale.rangeExtent() : internal.scaleExtent(internal.scale.range());
+    return internal.range;
+};
+AxisInternal.prototype.updateTickTextCharSize = function (tick) {
+    var internal = this;
+    if (internal.tickTextCharSize) {
+        return internal.tickTextCharSize;
+    }
+    var size = {
+        h: 11.5,
+        w: 5.5
+    };
+    tick.select('text').text(function(d) { return internal.textFormatted(d); }).each(function (d) {
+        var box = this.getBoundingClientRect(),
+            text = internal.textFormatted(d),
+            h = box.height,
+            w = text ? (box.width / text.length) : undefined;
+        if (h && w) {
+            size.h = h;
+            size.w = w;
+        }
+    }).text('');
+    internal.tickTextCharSize = size;
+    return size;
+};
+AxisInternal.prototype.isVertical = function () {
+    return this.orient === 'left' || this.orient === 'right';
+};
+AxisInternal.prototype.tspanData = function (d, i, scale) {
+    var internal = this;
+    var splitted = internal.params.tickMultiline ? internal.splitTickText(d, scale) : [].concat(internal.textFormatted(d));
+
+    if (internal.params.tickMultiline && internal.params.tickMultilineMax > 0) {
+        splitted = internal.ellipsify(splitted, internal.params.tickMultilineMax);
+    }
+
+    return splitted.map(function (s) {
+        return { index: i, splitted: s, length: splitted.length };
+    });
+};
+AxisInternal.prototype.splitTickText = function (d, scale) {
+    var internal = this,
+        tickText = internal.textFormatted(d),
+        maxWidth = internal.params.tickWidth,
+        subtext, spaceIndex, textWidth, splitted = [];
+
+    if (Object.prototype.toString.call(tickText) === "[object Array]") {
+        return tickText;
+    }
+
+    if (!maxWidth || maxWidth <= 0) {
+        maxWidth = internal.isVertical() ? 95 : internal.params.isCategory ? (Math.ceil(scale(1) - scale(0)) - 12) : 110;
+    }
+
+    function split(splitted, text) {
+        spaceIndex = undefined;
+        for (var i = 1; i < text.length; i++) {
+            if (text.charAt(i) === ' ') {
+                spaceIndex = i;
+            }
+            subtext = text.substr(0, i + 1);
+            textWidth = internal.tickTextCharSize.w * subtext.length;
+            // if text width gets over tick width, split by space index or crrent index
+            if (maxWidth < textWidth) {
+                return split(
+                    splitted.concat(text.substr(0, spaceIndex ? spaceIndex : i)),
+                    text.slice(spaceIndex ? spaceIndex + 1 : i)
+                );
+            }
+        }
+        return splitted.concat(text);
+    }
+
+    return split(splitted, tickText + "");
+};
+AxisInternal.prototype.ellipsify = function(splitted, max) {
+    if (splitted.length <= max) {
+        return splitted;
+    }
+
+    var ellipsified = splitted.slice(0, max);
+    var remaining = 3;
+    for (var i = max-1 ; i >= 0 ; i--) {
+        var available = ellipsified[i].length;
+
+        ellipsified[i] = ellipsified[i].substr(0, available-remaining).padEnd(available, '.');
+
+        remaining -= available;
+
+        if (remaining <= 0) {
+            break;
+        }
+    }
+
+    return ellipsified;
+};
+AxisInternal.prototype.updateTickLength = function () {
+    var internal = this;
+    internal.tickLength = Math.max(internal.innerTickSize, 0) + internal.tickPadding;
+};
+AxisInternal.prototype.lineY2 = function (d) {
+    var internal = this,
+        tickPosition = internal.scale(d) + (internal.tickCentered ? 0 : internal.tickOffset);
+    return internal.range[0] < tickPosition && tickPosition < internal.range[1] ? internal.innerTickSize : 0;
+};
+AxisInternal.prototype.textY = function (){
+    var internal = this, rotate = internal.tickTextRotate;
+    return rotate ? 11.5 - 2.5 * (rotate / 15) * (rotate > 0 ? 1 : -1) : internal.tickLength;
+};
+AxisInternal.prototype.textTransform = function () {
+    var internal = this, rotate = internal.tickTextRotate;
+    return rotate ? "rotate(" + rotate + ")" : "";
+};
+AxisInternal.prototype.textTextAnchor = function () {
+    var internal = this, rotate = internal.tickTextRotate;
+    return rotate ? (rotate > 0 ? "start" : "end") : "middle";
+};
+AxisInternal.prototype.tspanDx = function () {
+    var internal = this, rotate = internal.tickTextRotate;
+    return rotate ? 8 * Math.sin(Math.PI * (rotate / 180)) : 0;
+};
+AxisInternal.prototype.tspanDy = function (d, i) {
+    var internal = this,
+        dy = internal.tickTextCharSize.h;
+    if (i === 0) {
+        if (internal.isVertical()) {
+            dy = -((d.length - 1) * (internal.tickTextCharSize.h / 2) - 3);
+        } else {
+            dy = ".71em";
+        }
+    }
+    return dy;
+};
+
+
+AxisInternal.prototype.generateAxis = function () {
+    var internal = this, d3 = internal.d3, params = internal.params;
+    function axis(g, transition) {
+        var self;
+        g.each(function () {
+            var g = axis.g = d3.select(this);
+
+            var scale0 = this.__chart__ || internal.scale,
+                scale1 = this.__chart__ = internal.copyScale();
+
+            var ticksValues = internal.tickValues ? internal.tickValues : internal.generateTicks(scale1),
+                ticks = g.selectAll(".tick").data(ticksValues, scale1),
+                tickEnter = ticks.enter().insert("g", ".domain").attr("class", "tick").style("opacity", 1e-6),
+                // MEMO: No exit transition. The reason is this transition affects max tick width calculation because old tick will be included in the ticks.
+                tickExit = ticks.exit().remove(),
+                tickUpdate = ticks.merge(tickEnter),
+                tickTransform, tickX, tickY;
+
+            if (params.isCategory) {
+                internal.tickOffset = Math.ceil((scale1(1) - scale1(0)) / 2);
+                tickX = internal.tickCentered ? 0 : internal.tickOffset;
+                tickY = internal.tickCentered ? internal.tickOffset : 0;
+            } else {
+                internal.tickOffset = tickX = 0;
+            }
+
+            internal.updateRange();
+            internal.updateTickLength();
+            internal.updateTickTextCharSize(g.select('.tick'));
+
+            var lineUpdate = tickUpdate.select("line").merge(tickEnter.append("line")),
+                textUpdate = tickUpdate.select("text").merge(tickEnter.append("text"));
+
+            var tspans = tickUpdate.selectAll('text').selectAll('tspan').data(function (d, i) {
+                    return internal.tspanData(d, i, scale1);
+                }),
+                tspanEnter = tspans.enter().append('tspan'),
+                tspanUpdate = tspanEnter.merge(tspans).text(function (d) { return d.splitted; });
+            tspans.exit().remove();
+
+            var path = g.selectAll(".domain").data([ 0 ]),
+                pathUpdate = path.enter().append("path").merge(path).attr("class", "domain");
+
+            // TODO: each attr should be one function and change its behavior by internal.orient, probably
+            switch (internal.orient) {
+            case "bottom":
+                {
+                    tickTransform = internal.axisX;
+                    lineUpdate.attr("x1", tickX)
+                        .attr("x2", tickX)
+                        .attr("y2", function (d, i) { return internal.lineY2(d, i); });
+                    textUpdate.attr("x", 0)
+                        .attr("y", function (d, i) { return internal.textY(d, i); })
+                        .attr("transform", function (d, i) { return internal.textTransform(d, i); })
+                        .style("text-anchor", function (d, i) { return internal.textTextAnchor(d, i); });
+                    tspanUpdate.attr('x', 0)
+                        .attr("dy", function (d, i) { return internal.tspanDy(d, i); })
+                        .attr('dx', function (d, i) { return internal.tspanDx(d, i); });
+                    pathUpdate.attr("d", "M" + internal.range[0] + "," + internal.outerTickSize + "V0H" + internal.range[1] + "V" + internal.outerTickSize);
+                    break;
+                }
+            case "top":
+                {
+                    // TODO: rotated tick text
+                    tickTransform = internal.axisX;
+                    lineUpdate.attr("x1", tickX)
+                        .attr("x2", tickX)
+                        .attr("y2", function (d, i) { return -1 * internal.lineY2(d, i); });
+                    textUpdate.attr("x", 0)
+                        .attr("y", function (d, i) { return -1 * internal.textY(d, i) - (params.isCategory ? 2 : (internal.tickLength - 2)); })
+                        .attr("transform", function (d, i) { return internal.textTransform(d, i); })
+                        .style("text-anchor", function (d, i) { return internal.textTextAnchor(d, i); });
+                    tspanUpdate.attr('x', 0)
+                        .attr("dy", function (d, i) { return internal.tspanDy(d, i); })
+                        .attr('dx', function (d, i) { return internal.tspanDx(d, i); });
+                    pathUpdate.attr("d", "M" + internal.range[0] + "," + -internal.outerTickSize + "V0H" + internal.range[1] + "V" + -internal.outerTickSize);
+                    break;
+                }
+            case "left":
+                {
+                    tickTransform = internal.axisY;
+                    lineUpdate.attr("x2", -internal.innerTickSize)
+                        .attr("y1", tickY)
+                        .attr("y2", tickY);
+                    textUpdate.attr("x", -internal.tickLength)
+                        .attr("y", internal.tickOffset)
+                        .style("text-anchor", "end");
+                    tspanUpdate.attr('x', -internal.tickLength)
+                        .attr("dy", function (d, i) { return internal.tspanDy(d, i); });
+                    pathUpdate.attr("d", "M" + -internal.outerTickSize + "," + internal.range[0] + "H0V" + internal.range[1] + "H" + -internal.outerTickSize);
+                    break;
+                }
+            case "right":
+                {
+                    tickTransform = internal.axisY;
+                    lineUpdate.attr("x2", internal.innerTickSize)
+                        .attr("y1", tickY)
+                        .attr("y2", tickY);
+                    textUpdate.attr("x", internal.tickLength)
+                        .attr("y", internal.tickOffset)
+                        .style("text-anchor", "start");
+                    tspanUpdate.attr('x', internal.tickLength)
+                        .attr("dy", function (d, i) { return internal.tspanDy(d, i); });
+                    pathUpdate.attr("d", "M" + internal.outerTickSize + "," + internal.range[0] + "H0V" + internal.range[1] + "H" + internal.outerTickSize);
+                    break;
+                }
+            }
+            if (scale1.rangeBand) {
+                var x = scale1, dx = x.rangeBand() / 2;
+                scale0 = scale1 = function (d) {
+                    return x(d) + dx;
+                };
+            } else if (scale0.rangeBand) {
+                scale0 = scale1;
+            } else {
+                tickExit.call(tickTransform, scale1, internal.tickOffset);
+            }
+            tickEnter.call(tickTransform, scale0, internal.tickOffset);
+            self = (transition ? tickUpdate.transition(transition) : tickUpdate)
+                .style('opacity', 1)
+                .call(tickTransform, scale1, internal.tickOffset);
+        });
+        return self;
+    }
+    axis.scale = function (x) {
+        if (!arguments.length) { return internal.scale; }
+        internal.scale = x;
+        return axis;
+    };
+    axis.orient = function (x) {
+        if (!arguments.length) { return internal.orient; }
+        internal.orient = x in {top: 1, right: 1, bottom: 1, left: 1} ? x + "" : "bottom";
+        return axis;
+    };
+    axis.tickFormat = function (format) {
+        if (!arguments.length) { return internal.tickFormat; }
+        internal.tickFormat = format;
+        return axis;
+    };
+    axis.tickCentered = function (isCentered) {
+        if (!arguments.length) { return internal.tickCentered; }
+        internal.tickCentered = isCentered;
+        return axis;
+    };
+    axis.tickOffset = function () {
+        return internal.tickOffset;
+    };
+    axis.tickInterval = function () {
+        var interval, length;
+        if (params.isCategory) {
+            interval = internal.tickOffset * 2;
+        }
+        else {
+            length = axis.g.select('path.domain').node().getTotalLength() - internal.outerTickSize * 2;
+            interval = length / axis.g.selectAll('line').size();
+        }
+        return interval === Infinity ? 0 : interval;
+    };
+    axis.ticks = function () {
+        if (!arguments.length) { return internal.tickArguments; }
+        internal.tickArguments = arguments;
+        return axis;
+    };
+    axis.tickCulling = function (culling) {
+        if (!arguments.length) { return internal.tickCulling; }
+        internal.tickCulling = culling;
+        return axis;
+    };
+    axis.tickValues = function (x) {
+        if (typeof x === 'function') {
+            internal.tickValues = function () {
+                return x(internal.scale.domain());
+            };
+        }
+        else {
+            if (!arguments.length) { return internal.tickValues; }
+            internal.tickValues = x;
+        }
+        return axis;
+    };
+    return axis;
+};
+
+export {AxisInternal};

src/axis.js

@@ -1,416 +1,25 @@
 import CLASS from './class';
-import {isValue, isFunction, isString, isEmpty, Component } from './util';
-
-export var c3_axis_fn;
-export var c3_axis_internal_fn;
-
-function AxisInternal(component, params) {
-    var internal = this;
-    internal.component = component;
-    internal.params = params || {};
-
-    internal.d3 = component.d3;
-    internal.scale = internal.d3.scaleLinear();
-    internal.range;
-    internal.orient = "bottom";
-    internal.innerTickSize = 6;
-    internal.outerTickSize = this.params.withOuterTick ? 6 : 0;
-    internal.tickPadding = 3;
-    internal.tickValues = null;
-    internal.tickFormat;
-    internal.tickArguments;
-
-    internal.tickOffset = 0;
-    internal.tickCulling = true;
-    internal.tickCentered;
-    internal.tickTextCharSize;
-    internal.tickTextRotate = internal.params.tickTextRotate;
-    internal.tickLength;
-
-    internal.axis = internal.generateAxis();
-}
-c3_axis_internal_fn = AxisInternal.prototype;
-
-c3_axis_internal_fn.axisX = function (selection, x, tickOffset) {
-    selection.attr("transform", function (d) {
-        return "translate(" + Math.ceil(x(d) + tickOffset) + ", 0)";
-    });
-};
-c3_axis_internal_fn.axisY = function (selection, y) {
-    selection.attr("transform", function (d) {
-        return "translate(0," + Math.ceil(y(d)) + ")";
-    });
-};
-c3_axis_internal_fn.scaleExtent = function (domain) {
-    var start = domain[0], stop = domain[domain.length - 1];
-    return start < stop ? [ start, stop ] : [ stop, start ];
-};
-c3_axis_internal_fn.generateTicks = function (scale) {
-    var internal = this;
-    var i, domain, ticks = [];
-    if (scale.ticks) {
-        return scale.ticks.apply(scale, internal.tickArguments);
-    }
-    domain = scale.domain();
-    for (i = Math.ceil(domain[0]); i < domain[1]; i++) {
-        ticks.push(i);
-    }
-    if (ticks.length > 0 && ticks[0] > 0) {
-        ticks.unshift(ticks[0] - (ticks[1] - ticks[0]));
-    }
-    return ticks;
-};
-c3_axis_internal_fn.copyScale = function () {
-    var internal = this;
-    var newScale = internal.scale.copy(), domain;
-    if (internal.params.isCategory) {
-        domain = internal.scale.domain();
-        newScale.domain([domain[0], domain[1] - 1]);
-    }
-    return newScale;
-};
-c3_axis_internal_fn.textFormatted = function (v) {
-    var internal = this,
-        formatted = internal.tickFormat ? internal.tickFormat(v) : v;
-    return typeof formatted !== 'undefined' ? formatted : '';
-};
-c3_axis_internal_fn.updateRange = function () {
-    var internal = this;
-    internal.range = internal.scale.rangeExtent ? internal.scale.rangeExtent() : internal.scaleExtent(internal.scale.range());
-    return internal.range;
-};
-c3_axis_internal_fn.updateTickTextCharSize = function (tick) {
-    var internal = this;
-    if (internal.tickTextCharSize) {
-        return internal.tickTextCharSize;
-    }
-    var size = {
-        h: 11.5,
-        w: 5.5
-    };
-    tick.select('text').text(function(d) { return internal.textFormatted(d); }).each(function (d) {
-        var box = this.getBoundingClientRect(),
-            text = internal.textFormatted(d),
-            h = box.height,
-            w = text ? (box.width / text.length) : undefined;
-        if (h && w) {
-            size.h = h;
-            size.w = w;
-        }
-    }).text('');
-    internal.tickTextCharSize = size;
-    return size;
-};
-c3_axis_internal_fn.isVertical = function () {
-    return this.orient === 'left' || this.orient === 'right';
-};
-c3_axis_internal_fn.tspanData = function (d, i, scale) {
-    var internal = this;
-    var splitted = internal.params.tickMultiline ? internal.splitTickText(d, scale) : [].concat(internal.textFormatted(d));
-
-    if (internal.params.tickMultiline && internal.params.tickMultilineMax > 0) {
-        splitted = internal.ellipsify(splitted, internal.params.tickMultilineMax);
-    }
-
-    return splitted.map(function (s) {
-        return { index: i, splitted: s, length: splitted.length };
-    });
-};
-c3_axis_internal_fn.splitTickText = function (d, scale) {
-    var internal = this,
-        tickText = internal.textFormatted(d),
-        maxWidth = internal.params.tickWidth,
-        subtext, spaceIndex, textWidth, splitted = [];
-
-    if (Object.prototype.toString.call(tickText) === "[object Array]") {
-        return tickText;
-    }
-
-    if (!maxWidth || maxWidth <= 0) {
-        maxWidth = internal.isVertical() ? 95 : internal.params.isCategory ? (Math.ceil(scale(1) - scale(0)) - 12) : 110;
-    }
-
-    function split(splitted, text) {
-        spaceIndex = undefined;
-        for (var i = 1; i < text.length; i++) {
-            if (text.charAt(i) === ' ') {
-                spaceIndex = i;
-            }
-            subtext = text.substr(0, i + 1);
-            textWidth = internal.tickTextCharSize.w * subtext.length;
-            // if text width gets over tick width, split by space index or crrent index
-            if (maxWidth < textWidth) {
-                return split(
-                    splitted.concat(text.substr(0, spaceIndex ? spaceIndex : i)),
-                    text.slice(spaceIndex ? spaceIndex + 1 : i)
-                );
-            }
-        }
-        return splitted.concat(text);
-    }
-
-    return split(splitted, tickText + "");
-};
-c3_axis_internal_fn.ellipsify = function(splitted, max) {
-    if (splitted.length <= max) {
-        return splitted;
-    }
-
-    var ellipsified = splitted.slice(0, max);
-    var remaining = 3;
-    for (var i = max-1 ; i >= 0 ; i--) {
-        var available = ellipsified[i].length;
-
-        ellipsified[i] = ellipsified[i].substr(0, available-remaining).padEnd(available, '.');
-
-        remaining -= available;
-
-        if (remaining <= 0) {
-            break;
-        }
-    }
-
-    return ellipsified;
-};
-c3_axis_internal_fn.updateTickLength = function () {
-    var internal = this;
-    internal.tickLength = Math.max(internal.innerTickSize, 0) + internal.tickPadding;
-};
-c3_axis_internal_fn.lineY2 = function (d) {
-    var internal = this,
-        tickPosition = internal.scale(d) + (internal.tickCentered ? 0 : internal.tickOffset);
-    return internal.range[0] < tickPosition && tickPosition < internal.range[1] ? internal.innerTickSize : 0;
-};
-c3_axis_internal_fn.textY = function (){
-    var internal = this, rotate = internal.tickTextRotate;
-    return rotate ? 11.5 - 2.5 * (rotate / 15) * (rotate > 0 ? 1 : -1) : internal.tickLength;
-};
-c3_axis_internal_fn.textTransform = function () {
-    var internal = this, rotate = internal.tickTextRotate;
-    return rotate ? "rotate(" + rotate + ")" : "";
-};
-c3_axis_internal_fn.textTextAnchor = function () {
-    var internal = this, rotate = internal.tickTextRotate;
-    return rotate ? (rotate > 0 ? "start" : "end") : "middle";
-};
-c3_axis_internal_fn.tspanDx = function () {
-    var internal = this, rotate = internal.tickTextRotate;
-    return rotate ? 8 * Math.sin(Math.PI * (rotate / 180)) : 0;
-};
-c3_axis_internal_fn.tspanDy = function (d, i) {
-    var internal = this,
-        dy = internal.tickTextCharSize.h;
-    if (i === 0) {
-        if (internal.isVertical()) {
-            dy = -((d.length - 1) * (internal.tickTextCharSize.h / 2) - 3);
-        } else {
-            dy = ".71em";
-        }
-    }
-    return dy;
-};
-
-
-c3_axis_internal_fn.generateAxis = function () {
-    var internal = this, d3 = internal.d3, params = internal.params;
-    function axis(g, transition) {
-        var self;
-        g.each(function () {
-            var g = axis.g = d3.select(this);
-
-            var scale0 = this.__chart__ || internal.scale,
-                scale1 = this.__chart__ = internal.copyScale();
-
-            var ticksValues = internal.tickValues ? internal.tickValues : internal.generateTicks(scale1),
-                ticks = g.selectAll(".tick").data(ticksValues, scale1),
-                tickEnter = ticks.enter().insert("g", ".domain").attr("class", "tick").style("opacity", 1e-6),
-                // MEMO: No exit transition. The reason is this transition affects max tick width calculation because old tick will be included in the ticks.
-                tickExit = ticks.exit().remove(),
-                tickUpdate = ticks.merge(tickEnter),
-                tickTransform, tickX, tickY;
-
-            if (params.isCategory) {
-                internal.tickOffset = Math.ceil((scale1(1) - scale1(0)) / 2);
-                tickX = internal.tickCentered ? 0 : internal.tickOffset;
-                tickY = internal.tickCentered ? internal.tickOffset : 0;
-            } else {
-                internal.tickOffset = tickX = 0;
-            }
-
-            internal.updateRange();
-            internal.updateTickLength();
-            internal.updateTickTextCharSize(g.select('.tick'));
-
-            var lineUpdate = tickUpdate.select("line").merge(tickEnter.append("line")),
-                textUpdate = tickUpdate.select("text").merge(tickEnter.append("text"));
-
-            var tspans = tickUpdate.selectAll('text').selectAll('tspan').data(function (d, i) {
-                    return internal.tspanData(d, i, scale1);
-                }),
-                tspanEnter = tspans.enter().append('tspan'),
-                tspanUpdate = tspanEnter.merge(tspans).text(function (d) { return d.splitted; });
-            tspans.exit().remove();
-
-            var path = g.selectAll(".domain").data([ 0 ]),
-                pathUpdate = path.enter().append("path").merge(path).attr("class", "domain");
-
-            // TODO: each attr should be one function and change its behavior by internal.orient, probably
-            switch (internal.orient) {
-            case "bottom":
-                {
-                    tickTransform = internal.axisX;
-                    lineUpdate.attr("x1", tickX)
-                        .attr("x2", tickX)
-                        .attr("y2", function (d, i) { return internal.lineY2(d, i); });
-                    textUpdate.attr("x", 0)
-                        .attr("y", function (d, i) { return internal.textY(d, i); })
-                        .attr("transform", function (d, i) { return internal.textTransform(d, i); })
-                        .style("text-anchor", function (d, i) { return internal.textTextAnchor(d, i); });
-                    tspanUpdate.attr('x', 0)
-                        .attr("dy", function (d, i) { return internal.tspanDy(d, i); })
-                        .attr('dx', function (d, i) { return internal.tspanDx(d, i); });
-                    pathUpdate.attr("d", "M" + internal.range[0] + "," + internal.outerTickSize + "V0H" + internal.range[1] + "V" + internal.outerTickSize);
-                    break;
-                }
-            case "top":
-                {
-                    // TODO: rotated tick text
-                    tickTransform = internal.axisX;
-                    lineUpdate.attr("x1", tickX)
-                        .attr("x2", tickX)
-                        .attr("y2", function (d, i) { return -1 * internal.lineY2(d, i); });
-                    textUpdate.attr("x", 0)
-                        .attr("y", function (d, i) { return -1 * internal.textY(d, i) - (params.isCategory ? 2 : (internal.tickLength - 2)); })
-                        .attr("transform", function (d, i) { return internal.textTransform(d, i); })
-                        .style("text-anchor", function (d, i) { return internal.textTextAnchor(d, i); });
-                    tspanUpdate.attr('x', 0)
-                        .attr("dy", function (d, i) { return internal.tspanDy(d, i); })
-                        .attr('dx', function (d, i) { return internal.tspanDx(d, i); });
-                    pathUpdate.attr("d", "M" + internal.range[0] + "," + -internal.outerTickSize + "V0H" + internal.range[1] + "V" + -internal.outerTickSize);
-                    break;
-                }
-            case "left":
-                {
-                    tickTransform = internal.axisY;
-                    lineUpdate.attr("x2", -internal.innerTickSize)
-                        .attr("y1", tickY)
-                        .attr("y2", tickY);
-                    textUpdate.attr("x", -internal.tickLength)
-                        .attr("y", internal.tickOffset)
-                        .style("text-anchor", "end");
-                    tspanUpdate.attr('x', -internal.tickLength)
-                        .attr("dy", function (d, i) { return internal.tspanDy(d, i); });
-                    pathUpdate.attr("d", "M" + -internal.outerTickSize + "," + internal.range[0] + "H0V" + internal.range[1] + "H" + -internal.outerTickSize);
-                    break;
-                }
-            case "right":
-                {
-                    tickTransform = internal.axisY;
-                    lineUpdate.attr("x2", internal.innerTickSize)
-                        .attr("y1", tickY)
-                        .attr("y2", tickY);
-                    textUpdate.attr("x", internal.tickLength)
-                        .attr("y", internal.tickOffset)
-                        .style("text-anchor", "start");
-                    tspanUpdate.attr('x', internal.tickLength)
-                        .attr("dy", function (d, i) { return internal.tspanDy(d, i); });
-                    pathUpdate.attr("d", "M" + internal.outerTickSize + "," + internal.range[0] + "H0V" + internal.range[1] + "H" + internal.outerTickSize);
-                    break;
-                }
-            }
-            if (scale1.rangeBand) {
-                var x = scale1, dx = x.rangeBand() / 2;
-                scale0 = scale1 = function (d) {
-                    return x(d) + dx;
-                };
-            } else if (scale0.rangeBand) {
-                scale0 = scale1;
-            } else {
-                tickExit.call(tickTransform, scale1, internal.tickOffset);
-            }
-            tickEnter.call(tickTransform, scale0, internal.tickOffset);
-            self = (transition ? tickUpdate.transition(transition) : tickUpdate)
-                .style('opacity', 1)
-                .call(tickTransform, scale1, internal.tickOffset);
-        });
-        return self;
-    }
-    axis.scale = function (x) {
-        if (!arguments.length) { return internal.scale; }
-        internal.scale = x;
-        return axis;
-    };
-    axis.orient = function (x) {
-        if (!arguments.length) { return internal.orient; }
-        internal.orient = x in {top: 1, right: 1, bottom: 1, left: 1} ? x + "" : "bottom";
-        return axis;
-    };
-    axis.tickFormat = function (format) {
-        if (!arguments.length) { return internal.tickFormat; }
-        internal.tickFormat = format;
-        return axis;
-    };
-    axis.tickCentered = function (isCentered) {
-        if (!arguments.length) { return internal.tickCentered; }
-        internal.tickCentered = isCentered;
-        return axis;
-    };
-    axis.tickOffset = function () {
-        return internal.tickOffset;
-    };
-    axis.tickInterval = function () {
-        var interval, length;
-        if (params.isCategory) {
-            interval = internal.tickOffset * 2;
-        }
-        else {
-            length = axis.g.select('path.domain').node().getTotalLength() - internal.outerTickSize * 2;
-            interval = length / axis.g.selectAll('line').size();
-        }
-        return interval === Infinity ? 0 : interval;
-    };
-    axis.ticks = function () {
-        if (!arguments.length) { return internal.tickArguments; }
-        internal.tickArguments = arguments;
-        return axis;
-    };
-    axis.tickCulling = function (culling) {
-        if (!arguments.length) { return internal.tickCulling; }
-        internal.tickCulling = culling;
-        return axis;
-    };
-    axis.tickValues = function (x) {
-        if (typeof x === 'function') {
-            internal.tickValues = function () {
-                return x(internal.scale.domain());
-            };
-        }
-        else {
-            if (!arguments.length) { return internal.tickValues; }
-            internal.tickValues = x;
-        }
-        return axis;
-    };
-    return axis;
-};
-
-export default class Axis extends Component {
-    constructor (owner) {
-        var fn = {
-            fn: c3_axis_fn,
-            internal: {
-                fn: c3_axis_internal_fn
-            }
-        };
-        super(owner, 'axis', fn);
+import {
+    isValue,
+    isFunction,
+    isString,
+    isEmpty
+} from './util';
+import {
+    AxisInternal
+} from './axis-internal';
+
+export default class Axis {
+    constructor(owner) {
+        this.owner = owner;
         this.d3 = owner.d3;
         this.internal = AxisInternal;
     }
 }
-c3_axis_fn = Axis.prototype;
-
-c3_axis_fn.init = function init() {
-    var $$ = this.owner, config = $$.config, main = $$.main;
+Axis.prototype.init = function init() {
+    var $$ = this.owner,
+        config = $$.config,
+        main = $$.main;
     $$.axes.x = main.append("g")
         .attr("class", CLASS.axis + ' ' + CLASS.axisX)
         .attr("clip-path", config.axis_x_inner ? "" : $$.clipPathForXAxis)
@@ -440,8 +49,9 @@ c3_axis_fn.init = function init() {
         .attr("transform", config.axis_rotated ? "" : "rotate(-90)")
         .style("text-anchor", this.textAnchorForY2AxisLabel.bind(this));
 };
-c3_axis_fn.getXAxis = function getXAxis(scale, orient, tickFormat, tickValues, withOuterTick, withoutTransition, withoutRotateTickText) {
-    var $$ = this.owner, config = $$.config,
+Axis.prototype.getXAxis = function getXAxis(scale, orient, tickFormat, tickValues, withOuterTick, withoutTransition, withoutRotateTickText) {
+    var $$ = this.owner,
+        config = $$.config,
         axisParams = {
             isCategory: $$.isCategorized(),
             withOuterTick: withOuterTick,
@@ -454,7 +64,9 @@ c3_axis_fn.getXAxis = function getXAxis(scale, orient, tickFormat, tickValues, w
         axis = new this.internal(this, axisParams).axis.scale(scale).orient(orient);
 
     if ($$.isTimeSeries() && tickValues && typeof tickValues !== "function") {
-        tickValues = tickValues.map(function (v) { return $$.parseDate(v); });
+        tickValues = tickValues.map(function (v) {
+            return $$.parseDate(v);
+        });
     }
 
     // Set tick
@@ -468,8 +80,10 @@ c3_axis_fn.getXAxis = function getXAxis(scale, orient, tickFormat, tickValues, w
 
     return axis;
 };
-c3_axis_fn.updateXAxisTickValues = function updateXAxisTickValues(targets, axis) {
-    var $$ = this.owner, config = $$.config, tickValues;
+Axis.prototype.updateXAxisTickValues = function updateXAxisTickValues(targets, axis) {
+    var $$ = this.owner,
+        config = $$.config,
+        tickValues;
     if (config.axis_x_tick_fit || config.axis_x_tick_count) {
         tickValues = this.generateTickValues($$.mapTargetsToUniqueXs(targets), config.axis_x_tick_count, $$.isTimeSeries());
     }
@@ -481,8 +95,9 @@ c3_axis_fn.updateXAxisTickValues = function updateXAxisTickValues(targets, axis)
     }
     return tickValues;
 };
-c3_axis_fn.getYAxis = function getYAxis(scale, orient, tickFormat, tickValues, withOuterTick, withoutTransition, withoutRotateTickText) {
-    var $$ = this.owner, config = $$.config,
+Axis.prototype.getYAxis = function getYAxis(scale, orient, tickFormat, tickValues, withOuterTick, withoutTransition, withoutRotateTickText) {
+    var $$ = this.owner,
+        config = $$.config,
         axisParams = {
             withOuterTick: withOuterTick,
             withoutTransition: withoutTransition,
@@ -496,15 +111,18 @@ c3_axis_fn.getYAxis = function getYAxis(scale, orient, tickFormat, tickValues, w
     }
     return axis;
 };
-c3_axis_fn.getId = function getId(id) {
+Axis.prototype.getId = function getId(id) {
     var config = this.owner.config;
     return id in config.data_axes ? config.data_axes[id] : 'y';
 };
-c3_axis_fn.getXAxisTickFormat = function getXAxisTickFormat() {
+Axis.prototype.getXAxisTickFormat = function getXAxisTickFormat() {
     // #2251 previously set any negative values to a whole number,
     // however both should be truncated according to the users format specification
-    var $$ = this.owner, config = $$.config;
-    let format = ($$.isTimeSeries()) ? $$.defaultAxisTimeFormat : ($$.isCategorized()) ? $$.categoryName : function (v) { return v; };
+    var $$ = this.owner,
+        config = $$.config;
+    let format = ($$.isTimeSeries()) ? $$.defaultAxisTimeFormat : ($$.isCategorized()) ? $$.categoryName : function (v) {
+        return v;
+    };
 
     if (config.axis_x_tick_format) {
         if (isFunction(config.axis_x_tick_format)) {
@@ -515,22 +133,26 @@ c3_axis_fn.getXAxisTickFormat = function getXAxisTickFormat() {
             };
         }
     }
-    return isFunction(format) ? function (v) { return format.call($$, v); } : format;
+    return isFunction(format) ? function (v) {
+        return format.call($$, v);
+    } : format;
 };
-c3_axis_fn.getTickValues = function getTickValues(tickValues, axis) {
+Axis.prototype.getTickValues = function getTickValues(tickValues, axis) {
     return tickValues ? tickValues : axis ? axis.tickValues() : undefined;
 };
-c3_axis_fn.getXAxisTickValues = function getXAxisTickValues() {
+Axis.prototype.getXAxisTickValues = function getXAxisTickValues() {
     return this.getTickValues(this.owner.config.axis_x_tick_values, this.owner.xAxis);
 };
-c3_axis_fn.getYAxisTickValues = function getYAxisTickValues() {
+Axis.prototype.getYAxisTickValues = function getYAxisTickValues() {
     return this.getTickValues(this.owner.config.axis_y_tick_values, this.owner.yAxis);
 };
-c3_axis_fn.getY2AxisTickValues = function getY2AxisTickValues() {
+Axis.prototype.getY2AxisTickValues = function getY2AxisTickValues() {
     return this.getTickValues(this.owner.config.axis_y2_tick_values, this.owner.y2Axis);
 };
-c3_axis_fn.getLabelOptionByAxisId = function getLabelOptionByAxisId(axisId) {
-    var $$ = this.owner, config = $$.config, option;
+Axis.prototype.getLabelOptionByAxisId = function getLabelOptionByAxisId(axisId) {
+    var $$ = this.owner,
+        config = $$.config,
+        option;
     if (axisId === 'y') {
         option = config.axis_y_label;
     } else if (axisId === 'y2') {
@@ -540,12 +162,13 @@ c3_axis_fn.getLabelOptionByAxisId = function getLabelOptionByAxisId(axisId) {
     }
     return option;
 };
-c3_axis_fn.getLabelText = function getLabelText(axisId) {
+Axis.prototype.getLabelText = function getLabelText(axisId) {
     var option = this.getLabelOptionByAxisId(axisId);
     return isString(option) ? option : option ? option.text : null;
 };
-c3_axis_fn.setLabelText = function setLabelText(axisId, text) {
-    var $$ = this.owner, config = $$.config,
+Axis.prototype.setLabelText = function setLabelText(axisId, text) {
+    var $$ = this.owner,
+        config = $$.config,
         option = this.getLabelOptionByAxisId(axisId);
     if (isString(option)) {
         if (axisId === 'y') {
@@ -559,7 +182,7 @@ c3_axis_fn.setLabelText = function setLabelText(axisId, text) {
         option.text = text;
     }
 };
-c3_axis_fn.getLabelPosition = function getLabelPosition(axisId, defaultPosition) {
+Axis.prototype.getLabelPosition = function getLabelPosition(axisId, defaultPosition) {
     var option = this.getLabelOptionByAxisId(axisId),
         position = (option && typeof option === 'object' && option.position) ? option.position : defaultPosition;
     return {
@@ -573,28 +196,28 @@ c3_axis_fn.getLabelPosition = function getLabelPosition(axisId, defaultPosition)
         isBottom: position.indexOf('bottom') >= 0
     };
 };
-c3_axis_fn.getXAxisLabelPosition = function getXAxisLabelPosition() {
+Axis.prototype.getXAxisLabelPosition = function getXAxisLabelPosition() {
     return this.getLabelPosition('x', this.owner.config.axis_rotated ? 'inner-top' : 'inner-right');
 };
-c3_axis_fn.getYAxisLabelPosition = function getYAxisLabelPosition() {
+Axis.prototype.getYAxisLabelPosition = function getYAxisLabelPosition() {
     return this.getLabelPosition('y', this.owner.config.axis_rotated ? 'inner-right' : 'inner-top');
 };
-c3_axis_fn.getY2AxisLabelPosition = function getY2AxisLabelPosition() {
+Axis.prototype.getY2AxisLabelPosition = function getY2AxisLabelPosition() {
     return this.getLabelPosition('y2', this.owner.config.axis_rotated ? 'inner-right' : 'inner-top');
 };
-c3_axis_fn.getLabelPositionById = function getLabelPositionById(id) {
+Axis.prototype.getLabelPositionById = function getLabelPositionById(id) {
     return id === 'y2' ? this.getY2AxisLabelPosition() : id === 'y' ? this.getYAxisLabelPosition() : this.getXAxisLabelPosition();
 };
-c3_axis_fn.textForXAxisLabel = function textForXAxisLabel() {
+Axis.prototype.textForXAxisLabel = function textForXAxisLabel() {
     return this.getLabelText('x');
 };
-c3_axis_fn.textForYAxisLabel = function textForYAxisLabel() {
+Axis.prototype.textForYAxisLabel = function textForYAxisLabel() {
     return this.getLabelText('y');
 };
-c3_axis_fn.textForY2AxisLabel = function textForY2AxisLabel() {
+Axis.prototype.textForY2AxisLabel = function textForY2AxisLabel() {
     return this.getLabelText('y2');
 };
-c3_axis_fn.xForAxisLabel = function xForAxisLabel(forHorizontal, position) {
+Axis.prototype.xForAxisLabel = function xForAxisLabel(forHorizontal, position) {
     var $$ = this.owner;
     if (forHorizontal) {
         return position.isLeft ? 0 : position.isCenter ? $$.width / 2 : $$.width;
@@ -602,40 +225,41 @@ c3_axis_fn.xForAxisLabel = function xForAxisLabel(forHorizontal, position) {
         return position.isBottom ? -$$.height : position.isMiddle ? -$$.height / 2 : 0;
     }
 };
-c3_axis_fn.dxForAxisLabel = function dxForAxisLabel(forHorizontal, position) {
+Axis.prototype.dxForAxisLabel = function dxForAxisLabel(forHorizontal, position) {
     if (forHorizontal) {
         return position.isLeft ? "0.5em" : position.isRight ? "-0.5em" : "0";
     } else {
         return position.isTop ? "-0.5em" : position.isBottom ? "0.5em" : "0";
     }
 };
-c3_axis_fn.textAnchorForAxisLabel = function textAnchorForAxisLabel(forHorizontal, position) {
+Axis.prototype.textAnchorForAxisLabel = function textAnchorForAxisLabel(forHorizontal, position) {
     if (forHorizontal) {
         return position.isLeft ? 'start' : position.isCenter ? 'middle' : 'end';
     } else {
         return position.isBottom ? 'start' : position.isMiddle ? 'middle' : 'end';
     }
 };
-c3_axis_fn.xForXAxisLabel = function xForXAxisLabel() {
+Axis.prototype.xForXAxisLabel = function xForXAxisLabel() {
     return this.xForAxisLabel(!this.owner.config.axis_rotated, this.getXAxisLabelPosition());
 };
-c3_axis_fn.xForYAxisLabel = function xForYAxisLabel() {
+Axis.prototype.xForYAxisLabel = function xForYAxisLabel() {
     return this.xForAxisLabel(this.owner.config.axis_rotated, this.getYAxisLabelPosition());
 };
-c3_axis_fn.xForY2AxisLabel = function xForY2AxisLabel() {
+Axis.prototype.xForY2AxisLabel = function xForY2AxisLabel() {
     return this.xForAxisLabel(this.owner.config.axis_rotated, this.getY2AxisLabelPosition());
 };
-c3_axis_fn.dxForXAxisLabel = function dxForXAxisLabel() {
+Axis.prototype.dxForXAxisLabel = function dxForXAxisLabel() {
     return this.dxForAxisLabel(!this.owner.config.axis_rotated, this.getXAxisLabelPosition());
 };
-c3_axis_fn.dxForYAxisLabel = function dxForYAxisLabel() {
+Axis.prototype.dxForYAxisLabel = function dxForYAxisLabel() {
     return this.dxForAxisLabel(this.owner.config.axis_rotated, this.getYAxisLabelPosition());
 };
-c3_axis_fn.dxForY2AxisLabel = function dxForY2AxisLabel() {
+Axis.prototype.dxForY2AxisLabel = function dxForY2AxisLabel() {
     return this.dxForAxisLabel(this.owner.config.axis_rotated, this.getY2AxisLabelPosition());
 };
-c3_axis_fn.dyForXAxisLabel = function dyForXAxisLabel() {
-    var $$ = this.owner, config = $$.config,
+Axis.prototype.dyForXAxisLabel = function dyForXAxisLabel() {
+    var $$ = this.owner,
+        config = $$.config,
         position = this.getXAxisLabelPosition();
     if (config.axis_rotated) {
         return position.isInner ? "1.2em" : -25 - ($$.config.axis_x_inner ? 0 : this.getMaxTickWidth('x'));
@@ -643,7 +267,7 @@ c3_axis_fn.dyForXAxisLabel = function dyForXAxisLabel() {
         return position.isInner ? "-0.5em" : config.axis_x_height ? config.axis_x_height - 10 : "3em";
     }
 };
-c3_axis_fn.dyForYAxisLabel = function dyForYAxisLabel() {
+Axis.prototype.dyForYAxisLabel = function dyForYAxisLabel() {
     var $$ = this.owner,
         position = this.getYAxisLabelPosition();
     if ($$.config.axis_rotated) {
@@ -652,7 +276,7 @@ c3_axis_fn.dyForYAxisLabel = function dyForYAxisLabel() {
         return position.isInner ? "1.2em" : -10 - ($$.config.axis_y_inner ? 0 : (this.getMaxTickWidth('y') + 10));
     }
 };
-c3_axis_fn.dyForY2AxisLabel = function dyForY2AxisLabel() {
+Axis.prototype.dyForY2AxisLabel = function dyForY2AxisLabel() {
     var $$ = this.owner,
         position = this.getY2AxisLabelPosition();
     if ($$.config.axis_rotated) {
@@ -661,21 +285,23 @@ c3_axis_fn.dyForY2AxisLabel = function dyForY2AxisLabel() {
         return position.isInner ? "-0.5em" : 15 + ($$.config.axis_y2_inner ? 0 : (this.getMaxTickWidth('y2') + 15));
     }
 };
-c3_axis_fn.textAnchorForXAxisLabel = function textAnchorForXAxisLabel() {
+Axis.prototype.textAnchorForXAxisLabel = function textAnchorForXAxisLabel() {
     var $$ = this.owner;
     return this.textAnchorForAxisLabel(!$$.config.axis_rotated, this.getXAxisLabelPosition());
 };
-c3_axis_fn.textAnchorForYAxisLabel = function textAnchorForYAxisLabel() {
+Axis.prototype.textAnchorForYAxisLabel = function textAnchorForYAxisLabel() {
     var $$ = this.owner;
     return this.textAnchorForAxisLabel($$.config.axis_rotated, this.getYAxisLabelPosition());
 };
-c3_axis_fn.textAnchorForY2AxisLabel = function textAnchorForY2AxisLabel() {
+Axis.prototype.textAnchorForY2AxisLabel = function textAnchorForY2AxisLabel() {
     var $$ = this.owner;
     return this.textAnchorForAxisLabel($$.config.axis_rotated, this.getY2AxisLabelPosition());
 };
-c3_axis_fn.getMaxTickWidth = function getMaxTickWidth(id, withoutRecompute) {
-    var $$ = this.owner, config = $$.config,
-        maxWidth = 0, targetsToShow, scale, axis, dummy, svg;
+Axis.prototype.getMaxTickWidth = function getMaxTickWidth(id, withoutRecompute) {
+    var $$ = this.owner,
+        config = $$.config,
+        maxWidth = 0,
+        targetsToShow, scale, axis, dummy, svg;
     if (withoutRecompute && $$.currentMaxTickWidths[id]) {
         return $$.currentMaxTickWidths[id];
     }
@@ -694,40 +320,42 @@ c3_axis_fn.getMaxTickWidth = function getMaxTickWidth(id, withoutRecompute) {
         }
         dummy = $$.d3.select('body').append('div').classed('c3', true);
         svg = dummy.append("svg").style('visibility', 'hidden').style('position', 'fixed').style('top', 0).style('left', 0),
-        svg.append('g').call(axis).each(function () {
-            $$.d3.select(this).selectAll('text').each(function () {
-                var box = this.getBoundingClientRect();
-                if (maxWidth < box.width) { maxWidth = box.width; }
+            svg.append('g').call(axis).each(function () {
+                $$.d3.select(this).selectAll('text').each(function () {
+                    var box = this.getBoundingClientRect();
+                    if (maxWidth < box.width) {
+                        maxWidth = box.width;
+                    }
+                });
+                dummy.remove();
             });
-            dummy.remove();
-        });
     }
     $$.currentMaxTickWidths[id] = maxWidth <= 0 ? $$.currentMaxTickWidths[id] : maxWidth;
     return $$.currentMaxTickWidths[id];
 };
 
-c3_axis_fn.updateLabels = function updateLabels(withTransition) {
+Axis.prototype.updateLabels = function updateLabels(withTransition) {
     var $$ = this.owner;
     var axisXLabel = $$.main.select('.' + CLASS.axisX + ' .' + CLASS.axisXLabel),
         axisYLabel = $$.main.select('.' + CLASS.axisY + ' .' + CLASS.axisYLabel),
         axisY2Label = $$.main.select('.' + CLASS.axisY2 + ' .' + CLASS.axisY2Label);
     (withTransition ? axisXLabel.transition() : axisXLabel)
-        .attr("x", this.xForXAxisLabel.bind(this))
+    .attr("x", this.xForXAxisLabel.bind(this))
         .attr("dx", this.dxForXAxisLabel.bind(this))
         .attr("dy", this.dyForXAxisLabel.bind(this))
         .text(this.textForXAxisLabel.bind(this));
     (withTransition ? axisYLabel.transition() : axisYLabel)
-        .attr("x", this.xForYAxisLabel.bind(this))
+    .attr("x", this.xForYAxisLabel.bind(this))
         .attr("dx", this.dxForYAxisLabel.bind(this))
         .attr("dy", this.dyForYAxisLabel.bind(this))
         .text(this.textForYAxisLabel.bind(this));
     (withTransition ? axisY2Label.transition() : axisY2Label)
-        .attr("x", this.xForY2AxisLabel.bind(this))
+    .attr("x", this.xForY2AxisLabel.bind(this))
         .attr("dx", this.dxForY2AxisLabel.bind(this))
         .attr("dy", this.dyForY2AxisLabel.bind(this))
         .text(this.textForY2AxisLabel.bind(this));
 };
-c3_axis_fn.getPadding = function getPadding(padding, key, defaultValue, domainLength) {
+Axis.prototype.getPadding = function getPadding(padding, key, defaultValue, domainLength) {
     var p = typeof padding === 'number' ? padding : padding[key];
     if (!isValue(p)) {
         return defaultValue;
@@ -738,13 +366,14 @@ c3_axis_fn.getPadding = function getPadding(padding, key, defaultValue, domainLe
     // assume padding is pixels if unit is not specified
     return this.convertPixelsToAxisPadding(p, domainLength);
 };
-c3_axis_fn.convertPixelsToAxisPadding = function convertPixelsToAxisPadding(pixels, domainLength) {
+Axis.prototype.convertPixelsToAxisPadding = function convertPixelsToAxisPadding(pixels, domainLength) {
     var $$ = this.owner,
         length = $$.config.axis_rotated ? $$.width : $$.height;
     return domainLength * (pixels / length);
 };
-c3_axis_fn.generateTickValues = function generateTickValues(values, tickCount, forTimeSeries) {
-    var tickValues = values, targetCount, start, end, count, interval, i, tickValue;
+Axis.prototype.generateTickValues = function generateTickValues(values, tickCount, forTimeSeries) {
+    var tickValues = values,
+        targetCount, start, end, count, interval, i, tickValue;
     if (tickCount) {
         targetCount = isFunction(tickCount) ? tickCount() : tickCount;
         // compute ticks according to tickCount
@@ -766,11 +395,16 @@ c3_axis_fn.generateTickValues = function generateTickValues(values, tickCount, f
             tickValues.push(end);
         }
     }
-    if (!forTimeSeries) { tickValues = tickValues.sort(function (a, b) { return a - b; }); }
+    if (!forTimeSeries) {
+        tickValues = tickValues.sort(function (a, b) {
+            return a - b;
+        });
+    }
     return tickValues;
 };
-c3_axis_fn.generateTransitions = function generateTransitions(duration) {
-    var $$ = this.owner, axes = $$.axes;
+Axis.prototype.generateTransitions = function generateTransitions(duration) {
+    var $$ = this.owner,
+        axes = $$.axes;
     return {
         axisX: duration ? axes.x.transition().duration(duration) : axes.x,
         axisY: duration ? axes.y.transition().duration(duration) : axes.y,
@@ -778,7 +412,7 @@ c3_axis_fn.generateTransitions = function generateTransitions(duration) {
         axisSubX: duration ? axes.subx.transition().duration(duration) : axes.subx
     };
 };
-c3_axis_fn.redraw = function redraw(duration, isHidden) {
+Axis.prototype.redraw = function redraw(duration, isHidden) {
     var $$ = this.owner,
         transition = duration ? $$.d3.transition().duration(duration) : null;
     $$.axes.x.style("opacity", isHidden ? 0 : 1).call($$.xAxis, transition);

src/cache.js

@@ -1,15 +1,15 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.hasCaches = function (ids) {
+ChartInternal.prototype.hasCaches = function (ids) {
     for (var i = 0; i < ids.length; i++) {
         if (! (ids[i] in this.cache)) { return false; }
     }
     return true;
 };
-c3_chart_internal_fn.addCache = function (id, target) {
+ChartInternal.prototype.addCache = function (id, target) {
     this.cache[id] = this.cloneTarget(target);
 };
-c3_chart_internal_fn.getCaches = function (ids) {
+ChartInternal.prototype.getCaches = function (ids) {
     var targets = [], i;
     for (i = 0; i < ids.length; i++) {
         if (ids[i] in this.cache) { targets.push(this.cloneTarget(this.cache[ids[i]])); }

src/category.js

@@ -1,6 +1,6 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.categoryName = function (i) {
+ChartInternal.prototype.categoryName = function (i) {
     var config = this.config;
     return i < config.axis_x_categories.length ? config.axis_x_categories[i] : i;
 };

src/chart.js

@@ -0,0 +1,20 @@
+import {ChartInternal} from './chart-internal';
+
+export function Chart(config) {
+    var $$ = this.internal = new ChartInternal(this);
+    $$.loadConfig(config);
+
+    $$.beforeInit(config);
+    $$.init();
+    $$.afterInit(config);
+
+    // bind "this" to nested API
+    (function bindThis(fn, target, argThis) {
+        Object.keys(fn).forEach(function (key) {
+            target[key] = fn[key].bind(argThis);
+            if (Object.keys(fn[key]).length > 0) {
+                bindThis(fn[key], target[key], argThis);
+            }
+        });
+    })(Chart.prototype, this, this);
+}

src/class-utils.js

@@ -1,62 +1,62 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
 
-c3_chart_internal_fn.generateTargetClass = function (targetId) {
+ChartInternal.prototype.generateTargetClass = function (targetId) {
     return targetId || targetId === 0 ? ('-' + targetId).replace(/\s/g, '-') : '';
 };
-c3_chart_internal_fn.generateClass = function (prefix, targetId) {
+ChartInternal.prototype.generateClass = function (prefix, targetId) {
     return " " + prefix + " " + prefix + this.generateTargetClass(targetId);
 };
-c3_chart_internal_fn.classText = function (d) {
+ChartInternal.prototype.classText = function (d) {
     return this.generateClass(CLASS.text, d.index);
 };
-c3_chart_internal_fn.classTexts = function (d) {
+ChartInternal.prototype.classTexts = function (d) {
     return this.generateClass(CLASS.texts, d.id);
 };
-c3_chart_internal_fn.classShape = function (d) {
+ChartInternal.prototype.classShape = function (d) {
     return this.generateClass(CLASS.shape, d.index);
 };
-c3_chart_internal_fn.classShapes = function (d) {
+ChartInternal.prototype.classShapes = function (d) {
     return this.generateClass(CLASS.shapes, d.id);
 };
-c3_chart_internal_fn.classLine = function (d) {
+ChartInternal.prototype.classLine = function (d) {
     return this.classShape(d) + this.generateClass(CLASS.line, d.id);
 };
-c3_chart_internal_fn.classLines = function (d) {
+ChartInternal.prototype.classLines = function (d) {
     return this.classShapes(d) + this.generateClass(CLASS.lines, d.id);
 };
-c3_chart_internal_fn.classCircle = function (d) {
+ChartInternal.prototype.classCircle = function (d) {
     return this.classShape(d) + this.generateClass(CLASS.circle, d.index);
 };
-c3_chart_internal_fn.classCircles = function (d) {
+ChartInternal.prototype.classCircles = function (d) {
     return this.classShapes(d) + this.generateClass(CLASS.circles, d.id);
 };
-c3_chart_internal_fn.classBar = function (d) {
+ChartInternal.prototype.classBar = function (d) {
     return this.classShape(d) + this.generateClass(CLASS.bar, d.index);
 };
-c3_chart_internal_fn.classBars = function (d) {
+ChartInternal.prototype.classBars = function (d) {
     return this.classShapes(d) + this.generateClass(CLASS.bars, d.id);
 };
-c3_chart_internal_fn.classArc = function (d) {
+ChartInternal.prototype.classArc = function (d) {
     return this.classShape(d.data) + this.generateClass(CLASS.arc, d.data.id);
 };
-c3_chart_internal_fn.classArcs = function (d) {
+ChartInternal.prototype.classArcs = function (d) {
     return this.classShapes(d.data) + this.generateClass(CLASS.arcs, d.data.id);
 };
-c3_chart_internal_fn.classArea = function (d) {
+ChartInternal.prototype.classArea = function (d) {
     return this.classShape(d) + this.generateClass(CLASS.area, d.id);
 };
-c3_chart_internal_fn.classAreas = function (d) {
+ChartInternal.prototype.classAreas = function (d) {
     return this.classShapes(d) + this.generateClass(CLASS.areas, d.id);
 };
-c3_chart_internal_fn.classRegion = function (d, i) {
+ChartInternal.prototype.classRegion = function (d, i) {
     return this.generateClass(CLASS.region, i) + ' ' + ('class' in d ? d['class'] : '');
 };
-c3_chart_internal_fn.classEvent = function (d) {
+ChartInternal.prototype.classEvent = function (d) {
     return this.generateClass(CLASS.eventRect, d.index);
 };
-c3_chart_internal_fn.classTarget = function (id) {
+ChartInternal.prototype.classTarget = function (id) {
     var $$ = this;
     var additionalClassSuffix = $$.config.data_classes[id], additionalClass = '';
     if (additionalClassSuffix) {
@@ -64,43 +64,43 @@ c3_chart_internal_fn.classTarget = function (id) {
     }
     return $$.generateClass(CLASS.target, id) + additionalClass;
 };
-c3_chart_internal_fn.classFocus = function (d) {
+ChartInternal.prototype.classFocus = function (d) {
     return this.classFocused(d) + this.classDefocused(d);
 };
-c3_chart_internal_fn.classFocused = function (d) {
+ChartInternal.prototype.classFocused = function (d) {
     return ' ' + (this.focusedTargetIds.indexOf(d.id) >= 0 ? CLASS.focused : '');
 };
-c3_chart_internal_fn.classDefocused = function (d) {
+ChartInternal.prototype.classDefocused = function (d) {
     return ' ' + (this.defocusedTargetIds.indexOf(d.id) >= 0 ? CLASS.defocused : '');
 };
-c3_chart_internal_fn.classChartText = function (d) {
+ChartInternal.prototype.classChartText = function (d) {
     return CLASS.chartText + this.classTarget(d.id);
 };
-c3_chart_internal_fn.classChartLine = function (d) {
+ChartInternal.prototype.classChartLine = function (d) {
     return CLASS.chartLine + this.classTarget(d.id);
 };
-c3_chart_internal_fn.classChartBar = function (d) {
+ChartInternal.prototype.classChartBar = function (d) {
     return CLASS.chartBar + this.classTarget(d.id);
 };
-c3_chart_internal_fn.classChartArc = function (d) {
+ChartInternal.prototype.classChartArc = function (d) {
     return CLASS.chartArc + this.classTarget(d.data.id);
 };
-c3_chart_internal_fn.getTargetSelectorSuffix = function (targetId) {
+ChartInternal.prototype.getTargetSelectorSuffix = function (targetId) {
     return this.generateTargetClass(targetId)
         .replace(/([?!@#$%^&*()_=+,.<>'":;\[\]\/|~`{}\\])/g, '\\$1');
 };
-c3_chart_internal_fn.selectorTarget = function (id, prefix) {
+ChartInternal.prototype.selectorTarget = function (id, prefix) {
     return (prefix || '') + '.' + CLASS.target + this.getTargetSelectorSuffix(id);
 };
-c3_chart_internal_fn.selectorTargets = function (ids, prefix) {
+ChartInternal.prototype.selectorTargets = function (ids, prefix) {
     var $$ = this;
     ids = ids || [];
     return ids.length ? ids.map(function (id) { return $$.selectorTarget(id, prefix); }) : null;
 };
-c3_chart_internal_fn.selectorLegend = function (id) {
+ChartInternal.prototype.selectorLegend = function (id) {
     return '.' + CLASS.legendItem + this.getTargetSelectorSuffix(id);
 };
-c3_chart_internal_fn.selectorLegends = function (ids) {
+ChartInternal.prototype.selectorLegends = function (ids) {
     var $$ = this;
     return ids && ids.length ? ids.map(function (id) { return $$.selectorLegend(id); }) : null;
 };

src/clip.js

@@ -1,60 +1,60 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.getClipPath = function (id) {
+ChartInternal.prototype.getClipPath = function (id) {
     var isIE9 = window.navigator.appVersion.toLowerCase().indexOf("msie 9.") >= 0;
     return "url(" + (isIE9 ? "" : document.URL.split('#')[0]) + "#" + id + ")";
 };
-c3_chart_internal_fn.appendClip = function (parent, id) {
+ChartInternal.prototype.appendClip = function (parent, id) {
     return parent.append("clipPath").attr("id", id).append("rect");
 };
-c3_chart_internal_fn.getAxisClipX = function (forHorizontal) {
+ChartInternal.prototype.getAxisClipX = function (forHorizontal) {
     // axis line width + padding for left
     var left = Math.max(30, this.margin.left);
     return forHorizontal ? -(1 + left) : -(left - 1);
 };
-c3_chart_internal_fn.getAxisClipY = function (forHorizontal) {
+ChartInternal.prototype.getAxisClipY = function (forHorizontal) {
     return forHorizontal ? -20 : -this.margin.top;
 };
-c3_chart_internal_fn.getXAxisClipX = function () {
+ChartInternal.prototype.getXAxisClipX = function () {
     var $$ = this;
     return $$.getAxisClipX(!$$.config.axis_rotated);
 };
-c3_chart_internal_fn.getXAxisClipY = function () {
+ChartInternal.prototype.getXAxisClipY = function () {
     var $$ = this;
     return $$.getAxisClipY(!$$.config.axis_rotated);
 };
-c3_chart_internal_fn.getYAxisClipX = function () {
+ChartInternal.prototype.getYAxisClipX = function () {
     var $$ = this;
     return $$.config.axis_y_inner ? -1 : $$.getAxisClipX($$.config.axis_rotated);
 };
-c3_chart_internal_fn.getYAxisClipY = function () {
+ChartInternal.prototype.getYAxisClipY = function () {
     var $$ = this;
     return $$.getAxisClipY($$.config.axis_rotated);
 };
-c3_chart_internal_fn.getAxisClipWidth = function (forHorizontal) {
+ChartInternal.prototype.getAxisClipWidth = function (forHorizontal) {
     var $$ = this,
         left = Math.max(30, $$.margin.left),
         right = Math.max(30, $$.margin.right);
     // width + axis line width + padding for left/right
     return forHorizontal ? $$.width + 2 + left + right : $$.margin.left + 20;
 };
-c3_chart_internal_fn.getAxisClipHeight = function (forHorizontal) {
+ChartInternal.prototype.getAxisClipHeight = function (forHorizontal) {
     // less than 20 is not enough to show the axis label 'outer' without legend
     return (forHorizontal ? this.margin.bottom : (this.margin.top + this.height)) + 20;
 };
-c3_chart_internal_fn.getXAxisClipWidth = function () {
+ChartInternal.prototype.getXAxisClipWidth = function () {
     var $$ = this;
     return $$.getAxisClipWidth(!$$.config.axis_rotated);
 };
-c3_chart_internal_fn.getXAxisClipHeight = function () {
+ChartInternal.prototype.getXAxisClipHeight = function () {
     var $$ = this;
     return $$.getAxisClipHeight(!$$.config.axis_rotated);
 };
-c3_chart_internal_fn.getYAxisClipWidth = function () {
+ChartInternal.prototype.getYAxisClipWidth = function () {
     var $$ = this;
     return $$.getAxisClipWidth($$.config.axis_rotated) + ($$.config.axis_y_inner ? 20 : 0);
 };
-c3_chart_internal_fn.getYAxisClipHeight = function () {
+ChartInternal.prototype.getYAxisClipHeight = function () {
     var $$ = this;
     return $$.getAxisClipHeight($$.config.axis_rotated);
 };

src/color.js

@@ -1,7 +1,7 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { notEmpty } from './util';
 
-c3_chart_internal_fn.generateColor = function () {
+ChartInternal.prototype.generateColor = function () {
     var $$ = this, config = $$.config, d3 = $$.d3,
         colors = config.data_colors,
         pattern = notEmpty(config.color_pattern) ? config.color_pattern : d3.schemeCategory10,
@@ -28,7 +28,7 @@ c3_chart_internal_fn.generateColor = function () {
         return callback instanceof Function ? callback(color, d) : color;
     };
 };
-c3_chart_internal_fn.generateLevelColor = function () {
+ChartInternal.prototype.generateLevelColor = function () {
     var $$ = this, config = $$.config,
         colors = config.color_pattern,
         threshold = config.color_threshold,

src/config.js

@@ -1,7 +1,7 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isDefined } from './util';
 
-c3_chart_internal_fn.getDefaultConfig = function () {
+ChartInternal.prototype.getDefaultConfig = function () {
     var config = {
         bindto: '#chart',
         svg_classname: undefined,
@@ -243,9 +243,9 @@ c3_chart_internal_fn.getDefaultConfig = function () {
 
     return config;
 };
-c3_chart_internal_fn.additionalConfig = {};
+ChartInternal.prototype.additionalConfig = {};
 
-c3_chart_internal_fn.loadConfig = function (config) {
+ChartInternal.prototype.loadConfig = function (config) {
     var this_config = this.config, target, keys, read;
     function find() {
         var key = keys.shift();

src/core.js

@@ -1,73 +1,88 @@
+import {
+    ChartInternal
+} from './chart-internal';
+import {
+    Chart
+} from './chart';
+import {
+    AxisInternal
+} from './axis-internal';
 import Axis from './axis';
 import CLASS from './class';
+
 import {
-    c3,
-    isEmpty,
-    notEmpty,
-    isValue,
-    isFunction,
-    isString,
-    isUndefined,
-    isDefined,
-    ceil10,
     asHalfPixel,
-    diffDomain,
     getOption,
-    hasValue,
-    sanitise,
-    getPathBox 
+    getPathBox,
+    isFunction,
+    isValue,
+    notEmpty
 } from './util';
 
-export {c3};
-
-export var c3_chart_fn;
-export var c3_chart_internal_fn;
+var c3 = {
+    version: "0.6.4",
+    chart: {
+        fn: Chart.prototype,
+        internal: {
+            fn: ChartInternal.prototype,
+            axis: {
+                fn: Axis.prototype,
+                internal: {
+                    fn: AxisInternal.prototype
+                }
+            }
+        }
+    },
+    generate: function(config) {
+        return new Chart(config);
+    }
+};
 
-c3_chart_fn = c3.chart.fn;
-c3_chart_internal_fn = c3.chart.internal.fn;
+export {
+    c3
+};
 
-c3_chart_internal_fn.beforeInit = function () {
+ChartInternal.prototype.beforeInit = function() {
     // can do something
 };
-c3_chart_internal_fn.afterInit = function () {
+ChartInternal.prototype.afterInit = function() {
     // can do something
 };
-c3_chart_internal_fn.init = function () {
-    var $$ = this, config = $$.config;
+ChartInternal.prototype.init = function() {
+    var $$ = this,
+        config = $$.config;
 
     $$.initParams();
 
     if (config.data_url) {
         $$.convertUrlToData(config.data_url, config.data_mimeType, config.data_headers, config.data_keys, $$.initWithData);
-    }
-    else if (config.data_json) {
+    } else if (config.data_json) {
         $$.initWithData($$.convertJsonToData(config.data_json, config.data_keys));
-    }
-    else if (config.data_rows) {
+    } else if (config.data_rows) {
         $$.initWithData($$.convertRowsToData(config.data_rows));
-    }
-    else if (config.data_columns) {
+    } else if (config.data_columns) {
         $$.initWithData($$.convertColumnsToData(config.data_columns));
-    }
-    else {
+    } else {
         throw Error('url or json or rows or columns is required.');
     }
 };
 
-c3_chart_internal_fn.initParams = function () {
-    var $$ = this, d3 = $$.d3, config = $$.config;
+ChartInternal.prototype.initParams = function() {
+    var $$ = this,
+        d3 = $$.d3,
+        config = $$.config;
 
     // MEMO: clipId needs to be unique because it conflicts when multiple charts exist
-    $$.clipId = "c3-" + (+new Date()) + '-clip',
-    $$.clipIdForXAxis = $$.clipId + '-xaxis',
-    $$.clipIdForYAxis = $$.clipId + '-yaxis',
-    $$.clipIdForGrid = $$.clipId + '-grid',
-    $$.clipIdForSubchart = $$.clipId + '-subchart',
-    $$.clipPath = $$.getClipPath($$.clipId),
-    $$.clipPathForXAxis = $$.getClipPath($$.clipIdForXAxis),
+    $$.clipId = "c3-" + (+new Date()) + '-clip';
+    $$.clipIdForXAxis = $$.clipId + '-xaxis';
+    $$.clipIdForYAxis = $$.clipId + '-yaxis';
+    $$.clipIdForGrid = $$.clipId + '-grid';
+    $$.clipIdForSubchart = $$.clipId + '-subchart';
+    $$.clipPath = $$.getClipPath($$.clipId);
+    $$.clipPathForXAxis = $$.getClipPath($$.clipIdForXAxis);
     $$.clipPathForYAxis = $$.getClipPath($$.clipIdForYAxis);
-    $$.clipPathForGrid = $$.getClipPath($$.clipIdForGrid),
-    $$.clipPathForSubchart = $$.getClipPath($$.clipIdForSubchart),
+    $$.clipPathForGrid = $$.getClipPath($$.clipIdForGrid);
+    $$.clipPathForSubchart = $$.getClipPath($$.clipIdForSubchart);
 
     $$.dragStart = null;
     $$.dragging = false;
@@ -81,14 +96,28 @@ c3_chart_internal_fn.initParams = function () {
 
     $$.dataTimeParse = (config.data_xLocaltime ? d3.timeParse : d3.utcParse)($$.config.data_xFormat);
     $$.axisTimeFormat = config.axis_x_localtime ? d3.timeFormat : d3.utcFormat;
-    $$.defaultAxisTimeFormat = function (date) {
-        if (date.getMilliseconds()) { return d3.timeFormat(".%L")(date); }
-        if (date.getSeconds()) { return d3.timeFormat(":%S")(date); }
-        if (date.getMinutes()) { return d3.timeFormat("%I:%M")(date); }
-        if (date.getHours()) { return d3.timeFormat("%I %p")(date); }
-        if (date.getDay() && date.getDate() !== 1) { return d3.timeFormat("%-m/%-d")(date); }
-        if (date.getDate() !== 1) { return d3.timeFormat("%-m/%-d")(date); }
-        if (date.getMonth()) { return d3.timeFormat("%-m/%-d")(date); }
+    $$.defaultAxisTimeFormat = function(date) {
+        if (date.getMilliseconds()) {
+            return d3.timeFormat(".%L")(date);
+        }
+        if (date.getSeconds()) {
+            return d3.timeFormat(":%S")(date);
+        }
+        if (date.getMinutes()) {
+            return d3.timeFormat("%I:%M")(date);
+        }
+        if (date.getHours()) {
+            return d3.timeFormat("%I %p")(date);
+        }
+        if (date.getDay() && date.getDate() !== 1) {
+            return d3.timeFormat("%-m/%-d")(date);
+        }
+        if (date.getDate() !== 1) {
+            return d3.timeFormat("%-m/%-d")(date);
+        }
+        if (date.getMonth()) {
+            return d3.timeFormat("%-m/%-d")(date);
+        }
         return d3.timeFormat("%Y/%-m/%-d")(date);
     };
     $$.hiddenTargetIds = [];
@@ -126,27 +155,37 @@ c3_chart_internal_fn.initParams = function () {
     $$.axes.subx = d3.selectAll([]); // needs when excluding subchart.js
 };
 
-c3_chart_internal_fn.initChartElements = function () {
-    if (this.initBar) { this.initBar(); }
-    if (this.initLine) { this.initLine(); }
-    if (this.initArc) { this.initArc(); }
-    if (this.initGauge) { this.initGauge(); }
-    if (this.initText) { this.initText(); }
+ChartInternal.prototype.initChartElements = function() {
+    if (this.initBar) {
+        this.initBar();
+    }
+    if (this.initLine) {
+        this.initLine();
+    }
+    if (this.initArc) {
+        this.initArc();
+    }
+    if (this.initGauge) {
+        this.initGauge();
+    }
+    if (this.initText) {
+        this.initText();
+    }
 };
 
-c3_chart_internal_fn.initWithData = function (data) {
-    var $$ = this, d3 = $$.d3, config = $$.config;
+ChartInternal.prototype.initWithData = function(data) {
+    var $$ = this,
+        d3 = $$.d3,
+        config = $$.config;
     var defs, main, binding = true;
 
     $$.axis = new Axis($$);
 
     if (!config.bindto) {
         $$.selectChart = d3.selectAll([]);
-    }
-    else if (typeof config.bindto.node === 'function') {
+    } else if (typeof config.bindto.node === 'function') {
         $$.selectChart = config.bindto;
-    }
-    else {
+    } else {
         $$.selectChart = d3.select(config.bindto);
     }
     if ($$.selectChart.empty()) {
@@ -192,8 +231,12 @@ c3_chart_internal_fn.initWithData = function (data) {
     // Define svgs
     $$.svg = $$.selectChart.append("svg")
         .style("overflow", "hidden")
-        .on('mouseenter', function () { return config.onmouseover.call($$); })
-        .on('mouseleave', function () { return config.onmouseout.call($$); });
+        .on('mouseenter', function() {
+            return config.onmouseover.call($$);
+        })
+        .on('mouseleave', function() {
+            return config.onmouseout.call($$);
+        });
 
     if ($$.config.svg_classname) {
         $$.svg.attr('class', $$.config.svg_classname);
@@ -211,16 +254,30 @@ c3_chart_internal_fn.initWithData = function (data) {
     // Define regions
     main = $$.main = $$.svg.append("g").attr("transform", $$.getTranslate('main'));
 
-    if ($$.initPie) { $$.initPie(); }
-    if ($$.initSubchart) { $$.initSubchart(); }
-    if ($$.initTooltip) { $$.initTooltip(); }
-    if ($$.initLegend) { $$.initLegend(); }
-    if ($$.initTitle) { $$.initTitle(); }
-    if ($$.initZoom) { $$.initZoom(); }
+    if ($$.initPie) {
+        $$.initPie();
+    }
+    if ($$.initSubchart) {
+        $$.initSubchart();
+    }
+    if ($$.initTooltip) {
+        $$.initTooltip();
+    }
+    if ($$.initLegend) {
+        $$.initLegend();
+    }
+    if ($$.initTitle) {
+        $$.initTitle();
+    }
+    if ($$.initZoom) {
+        $$.initZoom();
+    }
 
     // Update selection based on size and scale
     // TODO: currently this must be called after initLegend because of update of sizes, but it should be done in initSubchart.
-    if ($$.initSubchartBrush) { $$.initSubchartBrush(); }
+    if ($$.initSubchartBrush) {
+        $$.initSubchartBrush();
+    }
 
     /*-- Main Region --*/
 
@@ -242,7 +299,9 @@ c3_chart_internal_fn.initWithData = function (data) {
         .attr('class', CLASS.chart);
 
     // Grid lines
-    if (config.grid_lines_front) { $$.initGridLines(); }
+    if (config.grid_lines_front) {
+        $$.initGridLines();
+    }
 
     // Cover whole with rects for events
     $$.initEventRect();
@@ -257,7 +316,9 @@ c3_chart_internal_fn.initWithData = function (data) {
     $$.updateTargets($$.data.targets);
 
     // Set default extent if defined
-    if (config.axis_x_selection) { $$.brush.selectionAsValue($$.getDefaultSelection()); }
+    if (config.axis_x_selection) {
+        $$.brush.selectionAsValue($$.getDefaultSelection());
+    }
 
     // Draw with targets
     if (binding) {
@@ -279,10 +340,10 @@ c3_chart_internal_fn.initWithData = function (data) {
     $$.api.element = $$.selectChart.node();
 };
 
-c3_chart_internal_fn.smoothLines = function (el, type) {
+ChartInternal.prototype.smoothLines = function(el, type) {
     var $$ = this;
     if (type === 'grid') {
-        el.each(function () {
+        el.each(function() {
             var g = $$.d3.select(this),
                 x1 = g.attr('x1'),
                 x2 = g.attr('x2'),
@@ -298,9 +359,9 @@ c3_chart_internal_fn.smoothLines = function (el, type) {
     }
 };
 
-
-c3_chart_internal_fn.updateSizes = function () {
-    var $$ = this, config = $$.config;
+ChartInternal.prototype.updateSizes = function() {
+    var $$ = this,
+        config = $$.config;
     var legendHeight = $$.legend ? $$.getLegendHeight() : 0,
         legendWidth = $$.legend ? $$.getLegendWidth() : 0,
         legendHeightForBottom = $$.isLegendRight || $$.isLegendInset ? 0 : legendHeight,
@@ -344,17 +405,27 @@ c3_chart_internal_fn.updateSizes = function () {
         bottom: 0,
         left: 0
     };
-    if ($$.updateSizeForLegend) { $$.updateSizeForLegend(legendHeight, legendWidth); }
+    if ($$.updateSizeForLegend) {
+        $$.updateSizeForLegend(legendHeight, legendWidth);
+    }
 
     $$.width = $$.currentWidth - $$.margin.left - $$.margin.right;
     $$.height = $$.currentHeight - $$.margin.top - $$.margin.bottom;
-    if ($$.width < 0) { $$.width = 0; }
-    if ($$.height < 0) { $$.height = 0; }
+    if ($$.width < 0) {
+        $$.width = 0;
+    }
+    if ($$.height < 0) {
+        $$.height = 0;
+    }
 
     $$.width2 = config.axis_rotated ? $$.margin.left - $$.rotated_padding_left - $$.rotated_padding_right : $$.width;
     $$.height2 = config.axis_rotated ? $$.height : $$.currentHeight - $$.margin2.top - $$.margin2.bottom;
-    if ($$.width2 < 0) { $$.width2 = 0; }
-    if ($$.height2 < 0) { $$.height2 = 0; }
+    if ($$.width2 < 0) {
+        $$.width2 = 0;
+    }
+    if ($$.height2 < 0) {
+        $$.height2 = 0;
+    }
 
     // for arc
     $$.arcWidth = $$.width - ($$.isLegendRight ? legendWidth + 10 : 0);
@@ -362,14 +433,16 @@ c3_chart_internal_fn.updateSizes = function () {
     if ($$.hasType('gauge') && !config.gauge_fullCircle) {
         $$.arcHeight += $$.height - $$.getGaugeLabelHeight();
     }
-    if ($$.updateRadius) { $$.updateRadius(); }
+    if ($$.updateRadius) {
+        $$.updateRadius();
+    }
 
     if ($$.isLegendRight && hasArc) {
         $$.margin3.left = $$.arcWidth / 2 + $$.radiusExpanded * 1.1;
     }
 };
 
-c3_chart_internal_fn.updateTargets = function (targets) {
+ChartInternal.prototype.updateTargets = function(targets) {
     var $$ = this;
 
     /*-- Main --*/
@@ -384,25 +457,36 @@ c3_chart_internal_fn.updateTargets = function (targets) {
     $$.updateTargetsForLine(targets);
 
     //-- Arc --//
-    if ($$.hasArcType() && $$.updateTargetsForArc) { $$.updateTargetsForArc(targets); }
+    if ($$.hasArcType() && $$.updateTargetsForArc) {
+        $$.updateTargetsForArc(targets);
+    }
 
     /*-- Sub --*/
 
-    if ($$.updateTargetsForSubchart) { $$.updateTargetsForSubchart(targets); }
+    if ($$.updateTargetsForSubchart) {
+        $$.updateTargetsForSubchart(targets);
+    }
 
     // Fade-in each chart
     $$.showTargets();
 };
-c3_chart_internal_fn.showTargets = function () {
+ChartInternal.prototype.showTargets = function() {
     var $$ = this;
-    $$.svg.selectAll('.' + CLASS.target).filter(function (d) { return $$.isTargetToShow(d.id); })
-      .transition().duration($$.config.transition_duration)
+    $$.svg.selectAll('.' + CLASS.target).filter(function(d) {
+            return $$.isTargetToShow(d.id);
+        })
+        .transition().duration($$.config.transition_duration)
         .style("opacity", 1);
 };
 
-c3_chart_internal_fn.redraw = function (options, transitions) {
-    var $$ = this, main = $$.main, d3 = $$.d3, config = $$.config;
-    var areaIndices = $$.getShapeIndices($$.isAreaType), barIndices = $$.getShapeIndices($$.isBarType), lineIndices = $$.getShapeIndices($$.isLineType);
+ChartInternal.prototype.redraw = function(options, transitions) {
+    var $$ = this,
+        main = $$.main,
+        d3 = $$.d3,
+        config = $$.config;
+    var areaIndices = $$.getShapeIndices($$.isAreaType),
+        barIndices = $$.getShapeIndices($$.isBarType),
+        lineIndices = $$.getShapeIndices($$.isLineType);
     var withY, withSubchart, withTransition, withTransitionForExit, withTransitionForAxis,
         withTransform, withUpdateXDomain, withUpdateOrgXDomain, withTrimXDomain, withLegend,
         withEventRect, withDimension, withUpdateXAxis;
@@ -410,8 +494,10 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
     var drawArea, drawBar, drawLine, xForText, yForText;
     var duration, durationForExit, durationForAxis;
     var transitionsToWait, waitForDraw, flow, transition;
-    var targetsToShow = $$.filterTargetsToShow($$.data.targets), tickValues, i, intervalForCulling, xDomainForZoom;
-    var xv = $$.xv.bind($$), cx, cy;
+    var targetsToShow = $$.filterTargetsToShow($$.data.targets),
+        tickValues, i, intervalForCulling, xDomainForZoom;
+    var xv = $$.xv.bind($$),
+        cx, cy;
 
     options = options || {};
     withY = getOption(options, "withY", true);
@@ -487,7 +573,7 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
                     break;
                 }
             }
-            $$.svg.selectAll('.' + CLASS.axisX + ' .tick text').each(function (e) {
+            $$.svg.selectAll('.' + CLASS.axisX + ' .tick text').each(function(e) {
                 var index = tickValues.indexOf(e);
                 if (index >= 0) {
                     d3.select(this).style('display', index % intervalForCulling ? 'none' : 'block');
@@ -525,11 +611,13 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
         .attr("x", $$.width / 2)
         .attr("y", $$.height / 2)
         .text(config.data_empty_label_text)
-      .transition()
+        .transition()
         .style('opacity', targetsToShow.length ? 0 : 1);
 
     // event rect
-    if (withEventRect) { $$.redrawEventRect(); }
+    if (withEventRect) {
+        $$.redrawEventRect();
+    }
 
     // grid
     $$.updateGrid(duration);
@@ -551,10 +639,14 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
     }
 
     // title
-    if ($$.redrawTitle) { $$.redrawTitle(); }
+    if ($$.redrawTitle) {
+        $$.redrawTitle();
+    }
 
     // arc
-    if ($$.redrawArc) { $$.redrawArc(duration, durationForExit, withTransform); }
+    if ($$.redrawArc) {
+        $$.redrawArc(duration, durationForExit, withTransform);
+    }
 
     // subchart
     if ($$.redrawSubchart) {
@@ -596,22 +688,25 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
                 $$.redrawText(xForText, yForText, options.flow, true, transition),
                 $$.redrawRegion(true, transition),
                 $$.redrawGrid(true, transition),
-            ].forEach(function (transitions) {
-                transitions.forEach(function (transition) {
+            ].forEach(function(transitions) {
+                transitions.forEach(function(transition) {
                     transitionsToWait.push(transition);
                 });
             });
             // Wait for end of transitions to call flow and onrendered callback
             waitForDraw = $$.generateWait();
-            transitionsToWait.forEach(function (t) {
+            transitionsToWait.forEach(function(t) {
                 waitForDraw.add(t);
             });
-            waitForDraw(function () {
-                if (flow) { flow(); }
-                if (config.onrendered) { config.onrendered.call($$); }
+            waitForDraw(function() {
+                if (flow) {
+                    flow();
+                }
+                if (config.onrendered) {
+                    config.onrendered.call($$);
+                }
             });
-        }
-        else {
+        } else {
             $$.redrawBar(drawBar);
             $$.redrawLine(drawLine);
             $$.redrawArea(drawArea);
@@ -619,19 +714,25 @@ c3_chart_internal_fn.redraw = function (options, transitions) {
             $$.redrawText(xForText, yForText, options.flow);
             $$.redrawRegion();
             $$.redrawGrid();
-            if (flow) { flow(); }
-            if (config.onrendered) { config.onrendered.call($$); }
+            if (flow) {
+                flow();
+            }
+            if (config.onrendered) {
+                config.onrendered.call($$);
+            }
         }
     }
 
     // update fadein condition
-    $$.mapToIds($$.data.targets).forEach(function (id) {
+    $$.mapToIds($$.data.targets).forEach(function(id) {
         $$.withoutFadeIn[id] = true;
     });
 };
 
-c3_chart_internal_fn.updateAndRedraw = function (options) {
-    var $$ = this, config = $$.config, transitions;
+ChartInternal.prototype.updateAndRedraw = function(options) {
+    var $$ = this,
+        config = $$.config,
+        transitions;
     options = options || {};
     // same with redraw
     options.withTransition = getOption(options, "withTransition", true);
@@ -656,7 +757,7 @@ c3_chart_internal_fn.updateAndRedraw = function (options) {
     // Draw with new sizes & scales
     $$.redraw(options, transitions);
 };
-c3_chart_internal_fn.redrawWithoutRescale = function () {
+ChartInternal.prototype.redrawWithoutRescale = function() {
     this.redraw({
         withY: false,
         withSubchart: false,
@@ -665,23 +766,26 @@ c3_chart_internal_fn.redrawWithoutRescale = function () {
     });
 };
 
-c3_chart_internal_fn.isTimeSeries = function () {
+ChartInternal.prototype.isTimeSeries = function() {
     return this.config.axis_x_type === 'timeseries';
 };
-c3_chart_internal_fn.isCategorized = function () {
+ChartInternal.prototype.isCategorized = function() {
     return this.config.axis_x_type.indexOf('categor') >= 0;
 };
-c3_chart_internal_fn.isCustomX = function () {
-    var $$ = this, config = $$.config;
+ChartInternal.prototype.isCustomX = function() {
+    var $$ = this,
+        config = $$.config;
     return !$$.isTimeSeries() && (config.data_x || notEmpty(config.data_xs));
 };
 
-c3_chart_internal_fn.isTimeSeriesY = function () {
+ChartInternal.prototype.isTimeSeriesY = function() {
     return this.config.axis_y_type === 'timeseries';
 };
 
-c3_chart_internal_fn.getTranslate = function (target) {
-    var $$ = this, config = $$.config, x, y;
+ChartInternal.prototype.getTranslate = function(target) {
+    var $$ = this,
+        config = $$.config,
+        x, y;
     if (target === 'main') {
         x = asHalfPixel($$.margin.left);
         y = asHalfPixel($$.margin.top);
@@ -705,66 +809,72 @@ c3_chart_internal_fn.getTranslate = function (target) {
         y = config.axis_rotated ? 0 : $$.height2;
     } else if (target === 'arc') {
         x = $$.arcWidth / 2;
-        y = $$.arcHeight / 2 - ($$.hasType('gauge') ? 6 : 0);// to prevent wrong display of min and max label
+        y = $$.arcHeight / 2 - ($$.hasType('gauge') ? 6 : 0); // to prevent wrong display of min and max label
     }
     return "translate(" + x + "," + y + ")";
 };
-c3_chart_internal_fn.initialOpacity = function (d) {
+ChartInternal.prototype.initialOpacity = function(d) {
     return d.value !== null && this.withoutFadeIn[d.id] ? 1 : 0;
 };
-c3_chart_internal_fn.initialOpacityForCircle = function (d) {
+ChartInternal.prototype.initialOpacityForCircle = function(d) {
     return d.value !== null && this.withoutFadeIn[d.id] ? this.opacityForCircle(d) : 0;
 };
-c3_chart_internal_fn.opacityForCircle = function (d) {
+ChartInternal.prototype.opacityForCircle = function(d) {
     var isPointShouldBeShown = isFunction(this.config.point_show) ? this.config.point_show(d) : this.config.point_show;
     var opacity = isPointShouldBeShown ? 1 : 0;
     return isValue(d.value) ? (this.isScatterType(d) ? 0.5 : opacity) : 0;
 };
-c3_chart_internal_fn.opacityForText = function () {
+ChartInternal.prototype.opacityForText = function() {
     return this.hasDataLabel() ? 1 : 0;
 };
-c3_chart_internal_fn.xx = function (d) {
+ChartInternal.prototype.xx = function(d) {
     return d ? this.x(d.x) : null;
 };
-c3_chart_internal_fn.xv = function (d) {
-    var $$ = this, value = d.value;
+ChartInternal.prototype.xv = function(d) {
+    var $$ = this,
+        value = d.value;
     if ($$.isTimeSeries()) {
         value = $$.parseDate(d.value);
-    }
-    else if ($$.isCategorized() && typeof d.value === 'string') {
+    } else if ($$.isCategorized() && typeof d.value === 'string') {
         value = $$.config.axis_x_categories.indexOf(d.value);
     }
     return Math.ceil($$.x(value));
 };
-c3_chart_internal_fn.yv = function (d) {
+ChartInternal.prototype.yv = function(d) {
     var $$ = this,
         yScale = d.axis && d.axis === 'y2' ? $$.y2 : $$.y;
     return Math.ceil(yScale(d.value));
 };
-c3_chart_internal_fn.subxx = function (d) {
+ChartInternal.prototype.subxx = function(d) {
     return d ? this.subX(d.x) : null;
 };
 
-c3_chart_internal_fn.transformMain = function (withTransition, transitions) {
+ChartInternal.prototype.transformMain = function(withTransition, transitions) {
     var $$ = this,
         xAxis, yAxis, y2Axis;
     if (transitions && transitions.axisX) {
         xAxis = transitions.axisX;
     } else {
-        xAxis  = $$.main.select('.' + CLASS.axisX);
-        if (withTransition) { xAxis = xAxis.transition(); }
+        xAxis = $$.main.select('.' + CLASS.axisX);
+        if (withTransition) {
+            xAxis = xAxis.transition();
+        }
     }
     if (transitions && transitions.axisY) {
         yAxis = transitions.axisY;
     } else {
         yAxis = $$.main.select('.' + CLASS.axisY);
-        if (withTransition) { yAxis = yAxis.transition(); }
+        if (withTransition) {
+            yAxis = yAxis.transition();
+        }
     }
     if (transitions && transitions.axisY2) {
         y2Axis = transitions.axisY2;
     } else {
         y2Axis = $$.main.select('.' + CLASS.axisY2);
-        if (withTransition) { y2Axis = y2Axis.transition(); }
+        if (withTransition) {
+            y2Axis = y2Axis.transition();
+        }
     }
     (withTransition ? $$.main.transition() : $$.main).attr("transform", $$.getTranslate('main'));
     xAxis.attr("transform", $$.getTranslate('x'));
@@ -772,14 +882,18 @@ c3_chart_internal_fn.transformMain = function (withTransition, transitions) {
     y2Axis.attr("transform", $$.getTranslate('y2'));
     $$.main.select('.' + CLASS.chartArcs).attr("transform", $$.getTranslate('arc'));
 };
-c3_chart_internal_fn.transformAll = function (withTransition, transitions) {
+ChartInternal.prototype.transformAll = function(withTransition, transitions) {
     var $$ = this;
     $$.transformMain(withTransition, transitions);
-    if ($$.config.subchart_show) { $$.transformContext(withTransition, transitions); }
-    if ($$.legend) { $$.transformLegend(withTransition); }
+    if ($$.config.subchart_show) {
+        $$.transformContext(withTransition, transitions);
+    }
+    if ($$.legend) {
+        $$.transformLegend(withTransition);
+    }
 };
 
-c3_chart_internal_fn.updateSvgSize = function () {
+ChartInternal.prototype.updateSvgSize = function() {
     var $$ = this,
         brush = $$.svg.select(".c3-brush .overlay");
     $$.svg.attr('width', $$.currentWidth).attr('height', $$.currentHeight);
@@ -803,8 +917,7 @@ c3_chart_internal_fn.updateSvgSize = function () {
     $$.selectChart.style('max-height', $$.currentHeight + "px");
 };
 
-
-c3_chart_internal_fn.updateDimension = function (withoutAxis) {
+ChartInternal.prototype.updateDimension = function(withoutAxis) {
     var $$ = this;
     if (!withoutAxis) {
         if ($$.config.axis_rotated) {
@@ -821,23 +934,26 @@ c3_chart_internal_fn.updateDimension = function (withoutAxis) {
     $$.transformAll(false);
 };
 
-c3_chart_internal_fn.observeInserted = function (selection) {
-    var $$ = this, observer;
+ChartInternal.prototype.observeInserted = function(selection) {
+    var $$ = this,
+        observer;
     if (typeof MutationObserver === 'undefined') {
         window.console.error("MutationObserver not defined.");
         return;
     }
-    observer= new MutationObserver(function (mutations) {
-        mutations.forEach(function (mutation) {
+    observer = new MutationObserver(function(mutations) {
+        mutations.forEach(function(mutation) {
             if (mutation.type === 'childList' && mutation.previousSibling) {
                 observer.disconnect();
                 // need to wait for completion of load because size calculation requires the actual sizes determined after that completion
-                $$.intervalForObserveInserted = window.setInterval(function () {
+                $$.intervalForObserveInserted = window.setInterval(function() {
                     // parentNode will NOT be null when completed
                     if (selection.node().parentNode) {
                         window.clearInterval($$.intervalForObserveInserted);
                         $$.updateDimension();
-                        if ($$.brush) { $$.brush.update(); }
+                        if ($$.brush) {
+                            $$.brush.update();
+                        }
                         $$.config.oninit.call($$);
                         $$.redraw({
                             withTransform: true,
@@ -853,23 +969,28 @@ c3_chart_internal_fn.observeInserted = function (selection) {
             }
         });
     });
-    observer.observe(selection.node(), {attributes: true, childList: true, characterData: true});
+    observer.observe(selection.node(), {
+        attributes: true,
+        childList: true,
+        characterData: true
+    });
 };
 
-c3_chart_internal_fn.bindResize = function () {
-    var $$ = this, config = $$.config;
+ChartInternal.prototype.bindResize = function() {
+    var $$ = this,
+        config = $$.config;
 
     $$.resizeFunction = $$.generateResize(); // need to call .remove
 
-    $$.resizeFunction.add(function () {
+    $$.resizeFunction.add(function() {
         config.onresize.call($$);
     });
     if (config.resize_auto) {
-        $$.resizeFunction.add(function () {
+        $$.resizeFunction.add(function() {
             if ($$.resizeTimeout !== undefined) {
                 window.clearTimeout($$.resizeTimeout);
             }
-            $$.resizeTimeout = window.setTimeout(function () {
+            $$.resizeTimeout = window.setTimeout(function() {
                 delete $$.resizeTimeout;
                 $$.updateAndRedraw({
                     withUpdateXDomain: false,
@@ -878,11 +999,13 @@ c3_chart_internal_fn.bindResize = function () {
                     withTransitionForTransform: false,
                     withLegend: true,
                 });
-                if ($$.brush) { $$.brush.update(); }
+                if ($$.brush) {
+                    $$.brush.update();
+                }
             }, 100);
         });
     }
-    $$.resizeFunction.add(function () {
+    $$.resizeFunction.add(function() {
         config.onresized.call($$);
     });
 
@@ -915,25 +1038,26 @@ c3_chart_internal_fn.bindResize = function () {
         window.onresize = function() {
             // if element not displayed skip it
             if (!$$.api.element.offsetParent) {
-                    return;
+                return;
             }
 
             wrapper();
-		};
+        };
     }
 };
 
-c3_chart_internal_fn.generateResize = function () {
+ChartInternal.prototype.generateResize = function() {
     var resizeFunctions = [];
+
     function callResizeFunctions() {
-        resizeFunctions.forEach(function (f) {
+        resizeFunctions.forEach(function(f) {
             f();
         });
     }
-    callResizeFunctions.add = function (f) {
+    callResizeFunctions.add = function(f) {
         resizeFunctions.push(f);
     };
-    callResizeFunctions.remove = function (f) {
+    callResizeFunctions.remove = function(f) {
         for (var i = 0; i < resizeFunctions.length; i++) {
             if (resizeFunctions[i] === f) {
                 resizeFunctions.splice(i, 1);
@@ -944,20 +1068,24 @@ c3_chart_internal_fn.generateResize = function () {
     return callResizeFunctions;
 };
 
-c3_chart_internal_fn.endall = function (transition, callback) {
+ChartInternal.prototype.endall = function(transition, callback) {
     var n = 0;
     transition
-        .each(function () { ++n; })
-        .on("end", function () {
-            if (!--n) { callback.apply(this, arguments); }
+        .each(function() {
+            ++n;
+        })
+        .on("end", function() {
+            if (!--n) {
+                callback.apply(this, arguments);
+            }
         });
 };
-c3_chart_internal_fn.generateWait = function () {
+ChartInternal.prototype.generateWait = function() {
     var transitionsToWait = [],
-        f = function (callback) {
-            var timer = setInterval(function () {
+        f = function(callback) {
+            var timer = setInterval(function() {
                 var done = 0;
-                transitionsToWait.forEach(function (t) {
+                transitionsToWait.forEach(function(t) {
                     if (t.empty()) {
                         done += 1;
                         return;
@@ -970,18 +1098,21 @@ c3_chart_internal_fn.generateWait = function () {
                 });
                 if (done === transitionsToWait.length) {
                     clearInterval(timer);
-                    if (callback) { callback(); }
+                    if (callback) {
+                        callback();
+                    }
                 }
             }, 50);
         };
-    f.add = function (transition) {
+    f.add = function(transition) {
         transitionsToWait.push(transition);
     };
     return f;
 };
 
-c3_chart_internal_fn.parseDate = function (date) {
-    var $$ = this, parsedDate;
+ChartInternal.prototype.parseDate = function(date) {
+    var $$ = this,
+        parsedDate;
     if (date instanceof Date) {
         parsedDate = date;
     } else if (typeof date === 'string') {
@@ -997,7 +1128,7 @@ c3_chart_internal_fn.parseDate = function (date) {
     return parsedDate;
 };
 
-c3_chart_internal_fn.isTabVisible = function () {
+ChartInternal.prototype.isTabVisible = function() {
     var hidden;
     if (typeof document.hidden !== "undefined") { // Opera 12.10 and Firefox 18 and later support
         hidden = "hidden";
@@ -1012,19 +1143,12 @@ c3_chart_internal_fn.isTabVisible = function () {
     return document[hidden] ? false : true;
 };
 
-c3_chart_internal_fn.isValue = isValue;
-c3_chart_internal_fn.isFunction = isFunction;
-c3_chart_internal_fn.isString = isString;
-c3_chart_internal_fn.isUndefined = isUndefined;
-c3_chart_internal_fn.isDefined = isDefined;
-c3_chart_internal_fn.ceil10 = ceil10;
-c3_chart_internal_fn.asHalfPixel = asHalfPixel;
-c3_chart_internal_fn.diffDomain = diffDomain;
-c3_chart_internal_fn.isEmpty = isEmpty;
-c3_chart_internal_fn.notEmpty = notEmpty;
-c3_chart_internal_fn.notEmpty = notEmpty;
-c3_chart_internal_fn.getOption = getOption;
-c3_chart_internal_fn.hasValue = hasValue;
-c3_chart_internal_fn.sanitise = sanitise;
-c3_chart_internal_fn.getPathBox = getPathBox;
-c3_chart_internal_fn.CLASS = CLASS;
+ChartInternal.prototype.getPathBox = getPathBox;
+ChartInternal.prototype.CLASS = CLASS;
+
+export {
+    Chart
+};
+export {
+    ChartInternal
+};

src/data.convert.js

@@ -1,7 +1,7 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isValue, isUndefined, isDefined, notEmpty, isArray } from './util';
 
-c3_chart_internal_fn.convertUrlToData = function (url, mimeType, headers, keys, done) {
+ChartInternal.prototype.convertUrlToData = function (url, mimeType, headers, keys, done) {
     var $$ = this, type = mimeType ? mimeType : 'csv', f, converter;
 
     if (type === 'json') {
@@ -21,7 +21,7 @@ c3_chart_internal_fn.convertUrlToData = function (url, mimeType, headers, keys,
         throw error;
     });
 };
-c3_chart_internal_fn.convertXsvToData = function (xsv) {
+ChartInternal.prototype.convertXsvToData = function (xsv) {
     var keys = xsv.columns, rows = xsv;
     if (rows.length === 0) {
         return { keys, rows: [ keys.reduce((row, key) => Object.assign(row, { [key]: null }), {}) ] };
@@ -31,7 +31,7 @@ c3_chart_internal_fn.convertXsvToData = function (xsv) {
         return { keys, rows: [].concat(xsv) };
     }
 };
-c3_chart_internal_fn.convertJsonToData = function (json, keys) {
+ChartInternal.prototype.convertJsonToData = function (json, keys) {
     var $$ = this,
         new_rows = [], targetKeys, data;
     if (keys) { // when keys specified, json would be an array that includes objects
@@ -63,7 +63,7 @@ c3_chart_internal_fn.convertJsonToData = function (json, keys) {
     }
     return data;
 };
-c3_chart_internal_fn.findValueInJson = function (object, path) {
+ChartInternal.prototype.findValueInJson = function (object, path) {
     path = path.replace(/\[(\w+)\]/g, '.$1'); // convert indexes to properties (replace [] with .)
     path = path.replace(/^\./, '');           // strip a leading dot
     var pathArray = path.split('.');
@@ -83,7 +83,7 @@ c3_chart_internal_fn.findValueInJson = function (object, path) {
  * @param {any[][]} rows The row data
  * @return {Object}
  */
-c3_chart_internal_fn.convertRowsToData = (rows) => {
+ChartInternal.prototype.convertRowsToData = (rows) => {
     const newRows = [];
     const keys = rows[0];
 
@@ -105,7 +105,7 @@ c3_chart_internal_fn.convertRowsToData = (rows) => {
  * @param {any[][]} columns The column data
  * @return {Object}
  */
-c3_chart_internal_fn.convertColumnsToData = (columns) => {
+ChartInternal.prototype.convertColumnsToData = (columns) => {
     const newRows = [];
     const keys = [];
 
@@ -134,7 +134,7 @@ c3_chart_internal_fn.convertColumnsToData = (columns) => {
  * @param {boolean} appendXs True to append to $$.data.xs, False to replace.
  * @return {!Array}
  */
-c3_chart_internal_fn.convertDataToTargets = function (data, appendXs) {
+ChartInternal.prototype.convertDataToTargets = function (data, appendXs) {
     var $$ = this, config = $$.config, targets, ids, xs, keys;
 
     // handles format where keys are not orderly provided

src/data.js

@@ -1,19 +1,29 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
-import { isValue, isFunction, isArray, notEmpty, hasValue } from './util';
+import {
+    ChartInternal
+} from './core';
+import {
+    isValue,
+    isFunction,
+    isArray,
+    notEmpty,
+    hasValue
+} from './util';
 
-c3_chart_internal_fn.isX = function (key) {
-    var $$ = this, config = $$.config;
+ChartInternal.prototype.isX = function (key) {
+    var $$ = this,
+        config = $$.config;
     return (config.data_x && key === config.data_x) || (notEmpty(config.data_xs) && hasValue(config.data_xs, key));
 };
-c3_chart_internal_fn.isNotX = function (key) {
+ChartInternal.prototype.isNotX = function (key) {
     return !this.isX(key);
 };
-c3_chart_internal_fn.getXKey = function (id) {
-    var $$ = this, config = $$.config;
+ChartInternal.prototype.getXKey = function (id) {
+    var $$ = this,
+        config = $$.config;
     return config.data_x ? config.data_x : notEmpty(config.data_xs) ? config.data_xs[id] : null;
 };
-c3_chart_internal_fn.getXValuesOfXKey = function (key, targets) {
+ChartInternal.prototype.getXValuesOfXKey = function (key, targets) {
     var $$ = this,
         xValues, ids = targets && notEmpty(targets) ? $$.mapToIds(targets) : [];
     ids.forEach(function (id) {
@@ -23,38 +33,41 @@ c3_chart_internal_fn.getXValuesOfXKey = function (key, targets) {
     });
     return xValues;
 };
-c3_chart_internal_fn.getXValue = function (id, i) {
+ChartInternal.prototype.getXValue = function (id, i) {
     var $$ = this;
     return id in $$.data.xs && $$.data.xs[id] && isValue($$.data.xs[id][i]) ? $$.data.xs[id][i] : i;
 };
-c3_chart_internal_fn.getOtherTargetXs = function () {
+ChartInternal.prototype.getOtherTargetXs = function () {
     var $$ = this,
         idsForX = Object.keys($$.data.xs);
     return idsForX.length ? $$.data.xs[idsForX[0]] : null;
 };
-c3_chart_internal_fn.getOtherTargetX = function (index) {
+ChartInternal.prototype.getOtherTargetX = function (index) {
     var xs = this.getOtherTargetXs();
     return xs && index < xs.length ? xs[index] : null;
 };
-c3_chart_internal_fn.addXs = function (xs) {
+ChartInternal.prototype.addXs = function (xs) {
     var $$ = this;
     Object.keys(xs).forEach(function (id) {
         $$.config.data_xs[id] = xs[id];
     });
 };
-c3_chart_internal_fn.addName = function (data) {
-    var $$ = this, name;
+ChartInternal.prototype.addName = function (data) {
+    var $$ = this,
+        name;
     if (data) {
         name = $$.config.data_names[data.id];
         data.name = name !== undefined ? name : data.id;
     }
     return data;
 };
-c3_chart_internal_fn.getValueOnIndex = function (values, index) {
-    var valueOnIndex = values.filter(function (v) { return v.index === index; });
+ChartInternal.prototype.getValueOnIndex = function (values, index) {
+    var valueOnIndex = values.filter(function (v) {
+        return v.index === index;
+    });
     return valueOnIndex.length ? valueOnIndex[0] : null;
 };
-c3_chart_internal_fn.updateTargetX = function (targets, x) {
+ChartInternal.prototype.updateTargetX = function (targets, x) {
     var $$ = this;
     targets.forEach(function (t) {
         t.values.forEach(function (v, i) {
@@ -63,7 +76,7 @@ c3_chart_internal_fn.updateTargetX = function (targets, x) {
         $$.data.xs[t.id] = x;
     });
 };
-c3_chart_internal_fn.updateTargetXs = function (targets, xs) {
+ChartInternal.prototype.updateTargetXs = function (targets, xs) {
     var $$ = this;
     targets.forEach(function (t) {
         if (xs[t.id]) {
@@ -71,41 +84,49 @@ c3_chart_internal_fn.updateTargetXs = function (targets, xs) {
         }
     });
 };
-c3_chart_internal_fn.generateTargetX = function (rawX, id, index) {
-    var $$ = this, x;
+ChartInternal.prototype.generateTargetX = function (rawX, id, index) {
+    var $$ = this,
+        x;
     if ($$.isTimeSeries()) {
         x = rawX ? $$.parseDate(rawX) : $$.parseDate($$.getXValue(id, index));
-    }
-    else if ($$.isCustomX() && !$$.isCategorized()) {
+    } else if ($$.isCustomX() && !$$.isCategorized()) {
         x = isValue(rawX) ? +rawX : $$.getXValue(id, index);
-    }
-    else {
+    } else {
         x = index;
     }
     return x;
 };
-c3_chart_internal_fn.cloneTarget = function (target) {
+ChartInternal.prototype.cloneTarget = function (target) {
     return {
-        id : target.id,
-        id_org : target.id_org,
-        values : target.values.map(function (d) {
-            return {x: d.x, value: d.value, id: d.id};
+        id: target.id,
+        id_org: target.id_org,
+        values: target.values.map(function (d) {
+            return {
+                x: d.x,
+                value: d.value,
+                id: d.id
+            };
         })
     };
 };
-c3_chart_internal_fn.getMaxDataCount = function () {
+ChartInternal.prototype.getMaxDataCount = function () {
     var $$ = this;
-    return $$.d3.max($$.data.targets, function (t) { return t.values.length; });
+    return $$.d3.max($$.data.targets, function (t) {
+        return t.values.length;
+    });
 };
-c3_chart_internal_fn.mapToIds = function (targets) {
-    return targets.map(function (d) { return d.id; });
+ChartInternal.prototype.mapToIds = function (targets) {
+    return targets.map(function (d) {
+        return d.id;
+    });
 };
-c3_chart_internal_fn.mapToTargetIds = function (ids) {
+ChartInternal.prototype.mapToTargetIds = function (ids) {
     var $$ = this;
     return ids ? [].concat(ids) : $$.mapToIds($$.data.targets);
 };
-c3_chart_internal_fn.hasTarget = function (targets, id) {
-    var ids = this.mapToIds(targets), i;
+ChartInternal.prototype.hasTarget = function (targets, id) {
+    var ids = this.mapToIds(targets),
+        i;
     for (i = 0; i < ids.length; i++) {
         if (ids[i] === id) {
             return true;
@@ -113,23 +134,35 @@ c3_chart_internal_fn.hasTarget = function (targets, id) {
     }
     return false;
 };
-c3_chart_internal_fn.isTargetToShow = function (targetId) {
+ChartInternal.prototype.isTargetToShow = function (targetId) {
     return this.hiddenTargetIds.indexOf(targetId) < 0;
 };
-c3_chart_internal_fn.isLegendToShow = function (targetId) {
+ChartInternal.prototype.isLegendToShow = function (targetId) {
     return this.hiddenLegendIds.indexOf(targetId) < 0;
 };
-c3_chart_internal_fn.filterTargetsToShow = function (targets) {
+ChartInternal.prototype.filterTargetsToShow = function (targets) {
     var $$ = this;
-    return targets.filter(function (t) { return $$.isTargetToShow(t.id); });
+    return targets.filter(function (t) {
+        return $$.isTargetToShow(t.id);
+    });
 };
-c3_chart_internal_fn.mapTargetsToUniqueXs = function (targets) {
+ChartInternal.prototype.mapTargetsToUniqueXs = function (targets) {
     var $$ = this;
-    var xs = $$.d3.set($$.d3.merge(targets.map(function (t) { return t.values.map(function (v) { return +v.x; }); }))).values();
-    xs = $$.isTimeSeries() ? xs.map(function (x) { return new Date(+x); }) : xs.map(function (x) { return +x; });
-    return xs.sort(function (a, b) { return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN; });
+    var xs = $$.d3.set($$.d3.merge(targets.map(function (t) {
+        return t.values.map(function (v) {
+            return +v.x;
+        });
+    }))).values();
+    xs = $$.isTimeSeries() ? xs.map(function (x) {
+        return new Date(+x);
+    }) : xs.map(function (x) {
+        return +x;
+    });
+    return xs.sort(function (a, b) {
+        return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
+    });
 };
-c3_chart_internal_fn.addHiddenTargetIds = function (targetIds) {
+ChartInternal.prototype.addHiddenTargetIds = function (targetIds) {
     targetIds = (targetIds instanceof Array) ? targetIds : new Array(targetIds);
     for (var i = 0; i < targetIds.length; i++) {
         if (this.hiddenTargetIds.indexOf(targetIds[i]) < 0) {
@@ -137,10 +170,12 @@ c3_chart_internal_fn.addHiddenTargetIds = function (targetIds) {
         }
     }
 };
-c3_chart_internal_fn.removeHiddenTargetIds = function (targetIds) {
-    this.hiddenTargetIds = this.hiddenTargetIds.filter(function (id) { return targetIds.indexOf(id) < 0; });
+ChartInternal.prototype.removeHiddenTargetIds = function (targetIds) {
+    this.hiddenTargetIds = this.hiddenTargetIds.filter(function (id) {
+        return targetIds.indexOf(id) < 0;
+    });
 };
-c3_chart_internal_fn.addHiddenLegendIds = function (targetIds) {
+ChartInternal.prototype.addHiddenLegendIds = function (targetIds) {
     targetIds = (targetIds instanceof Array) ? targetIds : new Array(targetIds);
     for (var i = 0; i < targetIds.length; i++) {
         if (this.hiddenLegendIds.indexOf(targetIds[i]) < 0) {
@@ -148,10 +183,12 @@ c3_chart_internal_fn.addHiddenLegendIds = function (targetIds) {
         }
     }
 };
-c3_chart_internal_fn.removeHiddenLegendIds = function (targetIds) {
-    this.hiddenLegendIds = this.hiddenLegendIds.filter(function (id) { return targetIds.indexOf(id) < 0; });
+ChartInternal.prototype.removeHiddenLegendIds = function (targetIds) {
+    this.hiddenLegendIds = this.hiddenLegendIds.filter(function (id) {
+        return targetIds.indexOf(id) < 0;
+    });
 };
-c3_chart_internal_fn.getValuesAsIdKeyed = function (targets) {
+ChartInternal.prototype.getValuesAsIdKeyed = function (targets) {
     var ys = {};
     targets.forEach(function (t) {
         ys[t.id] = [];
@@ -161,8 +198,9 @@ c3_chart_internal_fn.getValuesAsIdKeyed = function (targets) {
     });
     return ys;
 };
-c3_chart_internal_fn.checkValueInTargets = function (targets, checker) {
-    var ids = Object.keys(targets), i, j, values;
+ChartInternal.prototype.checkValueInTargets = function (targets, checker) {
+    var ids = Object.keys(targets),
+        i, j, values;
     for (i = 0; i < ids.length; i++) {
         values = targets[ids[i]].values;
         for (j = 0; j < values.length; j++) {
@@ -173,24 +211,33 @@ c3_chart_internal_fn.checkValueInTargets = function (targets, checker) {
     }
     return false;
 };
-c3_chart_internal_fn.hasNegativeValueInTargets = function (targets) {
-    return this.checkValueInTargets(targets, function (v) { return v < 0; });
+ChartInternal.prototype.hasNegativeValueInTargets = function (targets) {
+    return this.checkValueInTargets(targets, function (v) {
+        return v < 0;
+    });
 };
-c3_chart_internal_fn.hasPositiveValueInTargets = function (targets) {
-    return this.checkValueInTargets(targets, function (v) { return v > 0; });
+ChartInternal.prototype.hasPositiveValueInTargets = function (targets) {
+    return this.checkValueInTargets(targets, function (v) {
+        return v > 0;
+    });
 };
-c3_chart_internal_fn.isOrderDesc = function () {
+ChartInternal.prototype.isOrderDesc = function () {
     var config = this.config;
-    return typeof(config.data_order) === 'string' && config.data_order.toLowerCase() === 'desc';
+    return typeof (config.data_order) === 'string' && config.data_order.toLowerCase() === 'desc';
 };
-c3_chart_internal_fn.isOrderAsc = function () {
+ChartInternal.prototype.isOrderAsc = function () {
     var config = this.config;
-    return typeof(config.data_order) === 'string' && config.data_order.toLowerCase() === 'asc';
+    return typeof (config.data_order) === 'string' && config.data_order.toLowerCase() === 'asc';
 };
-c3_chart_internal_fn.getOrderFunction = function() {
-    var $$ = this, config = $$.config, orderAsc = $$.isOrderAsc(), orderDesc = $$.isOrderDesc();
+ChartInternal.prototype.getOrderFunction = function () {
+    var $$ = this,
+        config = $$.config,
+        orderAsc = $$.isOrderAsc(),
+        orderDesc = $$.isOrderDesc();
     if (orderAsc || orderDesc) {
-        var reducer = function (p, c) { return p + Math.abs(c.value); };
+        var reducer = function (p, c) {
+            return p + Math.abs(c.value);
+        };
         return function (t1, t2) {
             var t1Sum = t1.values.reduce(reducer, 0),
                 t2Sum = t2.values.reduce(reducer, 0);
@@ -205,20 +252,26 @@ c3_chart_internal_fn.getOrderFunction = function() {
         };
     }
 };
-c3_chart_internal_fn.orderTargets = function (targets) {
+ChartInternal.prototype.orderTargets = function (targets) {
     var fct = this.getOrderFunction();
     if (fct) {
         targets.sort(fct);
     }
     return targets;
 };
-c3_chart_internal_fn.filterByX = function (targets, x) {
-    return this.d3.merge(targets.map(function (t) { return t.values; })).filter(function (v) { return v.x - x === 0; });
+ChartInternal.prototype.filterByX = function (targets, x) {
+    return this.d3.merge(targets.map(function (t) {
+        return t.values;
+    })).filter(function (v) {
+        return v.x - x === 0;
+    });
 };
-c3_chart_internal_fn.filterRemoveNull = function (data) {
-    return data.filter(function (d) { return isValue(d.value); });
+ChartInternal.prototype.filterRemoveNull = function (data) {
+    return data.filter(function (d) {
+        return isValue(d.value);
+    });
 };
-c3_chart_internal_fn.filterByXDomain = function (targets, xDomain) {
+ChartInternal.prototype.filterByXDomain = function (targets, xDomain) {
     return targets.map(function (t) {
         return {
             id: t.id,
@@ -229,7 +282,7 @@ c3_chart_internal_fn.filterByXDomain = function (targets, xDomain) {
         };
     });
 };
-c3_chart_internal_fn.hasDataLabel = function () {
+ChartInternal.prototype.hasDataLabel = function () {
     var config = this.config;
     if (typeof config.data_labels === 'boolean' && config.data_labels) {
         return true;
@@ -238,27 +291,31 @@ c3_chart_internal_fn.hasDataLabel = function () {
     }
     return false;
 };
-c3_chart_internal_fn.getDataLabelLength = function (min, max, key) {
+ChartInternal.prototype.getDataLabelLength = function (min, max, key) {
     var $$ = this,
-        lengths = [0, 0], paddingCoef = 1.3;
+        lengths = [0, 0],
+        paddingCoef = 1.3;
     $$.selectChart.select('svg').selectAll('.dummy')
         .data([min, max])
         .enter().append('text')
-        .text(function (d) { return $$.dataLabelFormat(d.id)(d); })
+        .text(function (d) {
+            return $$.dataLabelFormat(d.id)(d);
+        })
         .each(function (d, i) {
             lengths[i] = this.getBoundingClientRect()[key] * paddingCoef;
         })
         .remove();
     return lengths;
 };
-c3_chart_internal_fn.isNoneArc = function (d) {
-    return this.hasTarget(this.data.targets, d.id);
-},
-c3_chart_internal_fn.isArc = function (d) {
-    return 'data' in d && this.hasTarget(this.data.targets, d.data.id);
-};
-c3_chart_internal_fn.findClosestFromTargets = function (targets, pos) {
-    var $$ = this, candidates;
+ChartInternal.prototype.isNoneArc = function (d) {
+        return this.hasTarget(this.data.targets, d.id);
+    },
+    ChartInternal.prototype.isArc = function (d) {
+        return 'data' in d && this.hasTarget(this.data.targets, d.data.id);
+    };
+ChartInternal.prototype.findClosestFromTargets = function (targets, pos) {
+    var $$ = this,
+        candidates;
 
     // map to array of closest points of each target
     candidates = targets.map(function (target) {
@@ -268,11 +325,15 @@ c3_chart_internal_fn.findClosestFromTargets = function (targets, pos) {
     // decide closest point and return
     return $$.findClosest(candidates, pos);
 };
-c3_chart_internal_fn.findClosest = function (values, pos) {
-    var $$ = this, minDist = $$.config.point_sensitivity, closest;
+ChartInternal.prototype.findClosest = function (values, pos) {
+    var $$ = this,
+        minDist = $$.config.point_sensitivity,
+        closest;
 
     // find mouseovering bar
-    values.filter(function (v) { return v && $$.isBarType(v.id); }).forEach(function (v) {
+    values.filter(function (v) {
+        return v && $$.isBarType(v.id);
+    }).forEach(function (v) {
         var shape = $$.main.select('.' + CLASS.bars + $$.getTargetSelectorSuffix(v.id) + ' .' + CLASS.bar + '-' + v.index).node();
         if (!closest && $$.isWithinBar($$.d3.mouse(shape), shape)) {
             closest = v;
@@ -280,7 +341,9 @@ c3_chart_internal_fn.findClosest = function (values, pos) {
     });
 
     // find closest point from non-bar
-    values.filter(function (v) { return v && !$$.isBarType(v.id); }).forEach(function (v) {
+    values.filter(function (v) {
+        return v && !$$.isBarType(v.id);
+    }).forEach(function (v) {
         var d = $$.dist(v, pos);
         if (d < minDist) {
             minDist = d;
@@ -290,16 +353,18 @@ c3_chart_internal_fn.findClosest = function (values, pos) {
 
     return closest;
 };
-c3_chart_internal_fn.dist = function (data, pos) {
-    var $$ = this, config = $$.config,
+ChartInternal.prototype.dist = function (data, pos) {
+    var $$ = this,
+        config = $$.config,
         xIndex = config.axis_rotated ? 1 : 0,
         yIndex = config.axis_rotated ? 0 : 1,
         y = $$.circleY(data, data.index),
         x = $$.x(data.x);
     return Math.sqrt(Math.pow(x - pos[xIndex], 2) + Math.pow(y - pos[yIndex], 2));
 };
-c3_chart_internal_fn.convertValuesToStep = function (values) {
-    var converted = [].concat(values), i;
+ChartInternal.prototype.convertValuesToStep = function (values) {
+    var converted = [].concat(values),
+        i;
 
     if (!this.isCategorized()) {
         return values;
@@ -322,12 +387,18 @@ c3_chart_internal_fn.convertValuesToStep = function (values) {
 
     return converted;
 };
-c3_chart_internal_fn.updateDataAttributes = function (name, attrs) {
-    var $$ = this, config = $$.config, current = config['data_' + name];
-    if (typeof attrs === 'undefined') { return current; }
+ChartInternal.prototype.updateDataAttributes = function (name, attrs) {
+    var $$ = this,
+        config = $$.config,
+        current = config['data_' + name];
+    if (typeof attrs === 'undefined') {
+        return current;
+    }
     Object.keys(attrs).forEach(function (id) {
         current[id] = attrs[id];
     });
-    $$.redraw({withLegend: true});
+    $$.redraw({
+        withLegend: true
+    });
     return current;
 };

src/data.load.js

@@ -1,7 +1,7 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.load = function (targets, args) {
+ChartInternal.prototype.load = function (targets, args) {
     var $$ = this;
     if (targets) {
         // filter loading targets if needed
@@ -36,7 +36,7 @@ c3_chart_internal_fn.load = function (targets, args) {
 
     if (args.done) { args.done(); }
 };
-c3_chart_internal_fn.loadFromArgs = function (args) {
+ChartInternal.prototype.loadFromArgs = function (args) {
     var $$ = this;
     if (args.data) {
         $$.load($$.convertDataToTargets(args.data), args);
@@ -59,7 +59,7 @@ c3_chart_internal_fn.loadFromArgs = function (args) {
         $$.load(null, args);
     }
 };
-c3_chart_internal_fn.unload = function (targetIds, done) {
+ChartInternal.prototype.unload = function (targetIds, done) {
     var $$ = this;
     if (!done) {
         done = function () {};

src/domain.js

@@ -1,7 +1,7 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isValue, isDefined, diffDomain, notEmpty } from './util';
 
-c3_chart_internal_fn.getYDomainMin = function (targets) {
+ChartInternal.prototype.getYDomainMin = function (targets) {
     var $$ = this, config = $$.config,
         ids = $$.mapToIds(targets), ys = $$.getValuesAsIdKeyed(targets),
         j, k, baseId, idsInGroup, id, hasNegativeValue;
@@ -32,7 +32,7 @@ c3_chart_internal_fn.getYDomainMin = function (targets) {
     }
     return $$.d3.min(Object.keys(ys).map(function (key) { return $$.d3.min(ys[key]); }));
 };
-c3_chart_internal_fn.getYDomainMax = function (targets) {
+ChartInternal.prototype.getYDomainMax = function (targets) {
     var $$ = this, config = $$.config,
         ids = $$.mapToIds(targets), ys = $$.getValuesAsIdKeyed(targets),
         j, k, baseId, idsInGroup, id, hasPositiveValue;
@@ -63,7 +63,7 @@ c3_chart_internal_fn.getYDomainMax = function (targets) {
     }
     return $$.d3.max(Object.keys(ys).map(function (key) { return $$.d3.max(ys[key]); }));
 };
-c3_chart_internal_fn.getYDomain = function (targets, axisId, xDomain) {
+ChartInternal.prototype.getYDomain = function (targets, axisId, xDomain) {
     var $$ = this, config = $$.config,
         targetsByAxisId = targets.filter(function (t) { return $$.axis.getId(t.id) === axisId; }),
         yTargets = xDomain ? $$.filterByXDomain(targetsByAxisId, xDomain) : targetsByAxisId,
@@ -145,19 +145,19 @@ c3_chart_internal_fn.getYDomain = function (targets, axisId, xDomain) {
     domain = [yDomainMin - padding_bottom, yDomainMax + padding_top];
     return isInverted ? domain.reverse() : domain;
 };
-c3_chart_internal_fn.getXDomainMin = function (targets) {
+ChartInternal.prototype.getXDomainMin = function (targets) {
     var $$ = this, config = $$.config;
     return isDefined(config.axis_x_min) ?
         ($$.isTimeSeries() ? this.parseDate(config.axis_x_min) : config.axis_x_min) :
     $$.d3.min(targets, function (t) { return $$.d3.min(t.values, function (v) { return v.x; }); });
 };
-c3_chart_internal_fn.getXDomainMax = function (targets) {
+ChartInternal.prototype.getXDomainMax = function (targets) {
     var $$ = this, config = $$.config;
     return isDefined(config.axis_x_max) ?
         ($$.isTimeSeries() ? this.parseDate(config.axis_x_max) : config.axis_x_max) :
     $$.d3.max(targets, function (t) { return $$.d3.max(t.values, function (v) { return v.x; }); });
 };
-c3_chart_internal_fn.getXDomainPadding = function (domain) {
+ChartInternal.prototype.getXDomainPadding = function (domain) {
     var $$ = this, config = $$.config,
         diff = domain[1] - domain[0],
         maxDataCount, padding, paddingLeft, paddingRight;
@@ -179,7 +179,7 @@ c3_chart_internal_fn.getXDomainPadding = function (domain) {
     }
     return {left: paddingLeft, right: paddingRight};
 };
-c3_chart_internal_fn.getXDomain = function (targets) {
+ChartInternal.prototype.getXDomain = function (targets) {
     var $$ = this,
         xDomain = [$$.getXDomainMin(targets), $$.getXDomainMax(targets)],
         firstX = xDomain[0], lastX = xDomain[1],
@@ -203,7 +203,7 @@ c3_chart_internal_fn.getXDomain = function (targets) {
     }
     return [min, max];
 };
-c3_chart_internal_fn.updateXDomain = function (targets, withUpdateXDomain, withUpdateOrgXDomain, withTrim, domain) {
+ChartInternal.prototype.updateXDomain = function (targets, withUpdateXDomain, withUpdateOrgXDomain, withTrim, domain) {
     var $$ = this, config = $$.config;
 
     if (withUpdateOrgXDomain) {
@@ -222,7 +222,7 @@ c3_chart_internal_fn.updateXDomain = function (targets, withUpdateXDomain, withU
 
     return $$.x.domain();
 };
-c3_chart_internal_fn.trimXDomain = function (domain) {
+ChartInternal.prototype.trimXDomain = function (domain) {
     var zoomDomain = this.getZoomDomain(),
         min = zoomDomain[0], max = zoomDomain[1];
     if (domain[0] <= min) {

src/drag.js

@@ -1,8 +1,8 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { getPathBox } from './util';
 
-c3_chart_internal_fn.drag = function (mouse) {
+ChartInternal.prototype.drag = function (mouse) {
     var $$ = this, config = $$.config, main = $$.main, d3 = $$.d3;
     var sx, sy, mx, my, minX, maxX, minY, maxY;
 
@@ -59,7 +59,7 @@ c3_chart_internal_fn.drag = function (mouse) {
         });
 };
 
-c3_chart_internal_fn.dragstart = function (mouse) {
+ChartInternal.prototype.dragstart = function (mouse) {
     var $$ = this, config = $$.config;
     if ($$.hasArcType()) { return; }
     if (! config.data_selection_enabled) { return; } // do nothing if not selectable
@@ -70,7 +70,7 @@ c3_chart_internal_fn.dragstart = function (mouse) {
     $$.dragging = true;
 };
 
-c3_chart_internal_fn.dragend = function () {
+ChartInternal.prototype.dragend = function () {
     var $$ = this, config = $$.config;
     if ($$.hasArcType()) { return; }
     if (! config.data_selection_enabled) { return; } // do nothing if not selectable

src/format.js

@@ -1,7 +1,7 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isValue } from './util';
 
-c3_chart_internal_fn.getYFormat = function (forArc) {
+ChartInternal.prototype.getYFormat = function (forArc) {
     var $$ = this,
         formatForY = forArc && !$$.hasType('gauge') ? $$.defaultArcValueFormat : $$.yFormat,
         formatForY2 = forArc && !$$.hasType('gauge') ? $$.defaultArcValueFormat : $$.y2Format;
@@ -10,23 +10,23 @@ c3_chart_internal_fn.getYFormat = function (forArc) {
         return format.call($$, v, ratio);
     };
 };
-c3_chart_internal_fn.yFormat = function (v) {
+ChartInternal.prototype.yFormat = function (v) {
     var $$ = this, config = $$.config,
         format = config.axis_y_tick_format ? config.axis_y_tick_format : $$.defaultValueFormat;
     return format(v);
 };
-c3_chart_internal_fn.y2Format = function (v) {
+ChartInternal.prototype.y2Format = function (v) {
     var $$ = this, config = $$.config,
         format = config.axis_y2_tick_format ? config.axis_y2_tick_format : $$.defaultValueFormat;
     return format(v);
 };
-c3_chart_internal_fn.defaultValueFormat = function (v) {
+ChartInternal.prototype.defaultValueFormat = function (v) {
     return isValue(v) ? +v : "";
 };
-c3_chart_internal_fn.defaultArcValueFormat = function (v, ratio) {
+ChartInternal.prototype.defaultArcValueFormat = function (v, ratio) {
     return (ratio * 100).toFixed(1) + '%';
 };
-c3_chart_internal_fn.dataLabelFormat = function (targetId) {
+ChartInternal.prototype.dataLabelFormat = function (targetId) {
     var $$ = this, data_labels = $$.config.data_labels,
         format, defaultFormat = function (v) { return isValue(v) ? +v : ""; };
     // find format according to axis id

src/grid.js

@@ -1,8 +1,8 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isValue } from './util';
 
-c3_chart_internal_fn.initGrid = function () {
+ChartInternal.prototype.initGrid = function () {
     var $$ = this, config = $$.config, d3 = $$.d3;
     $$.grid = $$.main.append('g')
         .attr("clip-path", $$.clipPathForGrid)
@@ -22,7 +22,7 @@ c3_chart_internal_fn.initGrid = function () {
     $$.xgrid = d3.selectAll([]);
     if (!config.grid_lines_front) { $$.initGridLines(); }
 };
-c3_chart_internal_fn.initGridLines = function () {
+ChartInternal.prototype.initGridLines = function () {
     var $$ = this, d3 = $$.d3;
     $$.gridLines = $$.main.append('g')
         .attr("clip-path", $$.clipPathForGrid)
@@ -31,7 +31,7 @@ c3_chart_internal_fn.initGridLines = function () {
     $$.gridLines.append('g').attr('class', CLASS.ygridLines);
     $$.xgridLines = d3.selectAll([]);
 };
-c3_chart_internal_fn.updateXGrid = function (withoutUpdate) {
+ChartInternal.prototype.updateXGrid = function (withoutUpdate) {
     var $$ = this, config = $$.config, d3 = $$.d3,
         xgridData = $$.generateGridData(config.grid_x_type, $$.x),
         tickOffset = $$.isCategorized() ? $$.xAxis.tickOffset() : 0;
@@ -73,7 +73,7 @@ c3_chart_internal_fn.updateXGrid = function (withoutUpdate) {
     xgrid.exit().remove();
 };
 
-c3_chart_internal_fn.updateYGrid = function () {
+ChartInternal.prototype.updateYGrid = function () {
     var $$ = this, config = $$.config,
         gridValues = $$.yAxis.tickValues() || $$.y.ticks(config.grid_y_ticks);
     var ygrid = $$.main.select('.' + CLASS.ygrids).selectAll('.' + CLASS.ygrid)
@@ -91,19 +91,19 @@ c3_chart_internal_fn.updateYGrid = function () {
     $$.smoothLines($$.ygrid, 'grid');
 };
 
-c3_chart_internal_fn.gridTextAnchor = function (d) {
+ChartInternal.prototype.gridTextAnchor = function (d) {
     return d.position ? d.position : "end";
 };
-c3_chart_internal_fn.gridTextDx = function (d) {
+ChartInternal.prototype.gridTextDx = function (d) {
     return d.position === 'start' ? 4 : d.position === 'middle' ? 0 : -4;
 };
-c3_chart_internal_fn.xGridTextX = function (d) {
+ChartInternal.prototype.xGridTextX = function (d) {
     return d.position === 'start' ? -this.height : d.position === 'middle' ? -this.height / 2 : 0;
 };
-c3_chart_internal_fn.yGridTextX = function (d) {
+ChartInternal.prototype.yGridTextX = function (d) {
     return d.position === 'start' ? 0 : d.position === 'middle' ? this.width / 2 : this.width;
 };
-c3_chart_internal_fn.updateGrid = function (duration) {
+ChartInternal.prototype.updateGrid = function (duration) {
     var $$ = this, main = $$.main, config = $$.config,
         xgridLine, xgridLineEnter, ygridLine, ygridLineEnter,
         xv = $$.xv.bind($$), yv = $$.yv.bind($$),
@@ -186,7 +186,7 @@ c3_chart_internal_fn.updateGrid = function (duration) {
         .style("opacity", 0)
         .remove();
 };
-c3_chart_internal_fn.redrawGrid = function (withTransition, transition) {
+ChartInternal.prototype.redrawGrid = function (withTransition, transition) {
     var $$ = this, config = $$.config, xv = $$.xv.bind($$),
         lines = $$.xgridLines.select('line'),
         texts = $$.xgridLines.select('text');
@@ -204,7 +204,7 @@ c3_chart_internal_fn.redrawGrid = function (withTransition, transition) {
             .style("opacity", 1)
     ];
 };
-c3_chart_internal_fn.showXGridFocus = function (selectedData) {
+ChartInternal.prototype.showXGridFocus = function (selectedData) {
     var $$ = this, config = $$.config,
         dataToShow = selectedData.filter(function (d) { return d && isValue(d.value); }),
         focusEl = $$.main.selectAll('line.' + CLASS.xgridFocus),
@@ -219,10 +219,10 @@ c3_chart_internal_fn.showXGridFocus = function (selectedData) {
         .attr(config.axis_rotated ? 'y2' : 'x2', xx);
     $$.smoothLines(focusEl, 'grid');
 };
-c3_chart_internal_fn.hideXGridFocus = function () {
+ChartInternal.prototype.hideXGridFocus = function () {
     this.main.select('line.' + CLASS.xgridFocus).style("visibility", "hidden");
 };
-c3_chart_internal_fn.updateXgridFocus = function () {
+ChartInternal.prototype.updateXgridFocus = function () {
     var $$ = this, config = $$.config;
     $$.main.select('line.' + CLASS.xgridFocus)
         .attr("x1", config.axis_rotated ? 0 : -10)
@@ -230,7 +230,7 @@ c3_chart_internal_fn.updateXgridFocus = function () {
         .attr("y1", config.axis_rotated ? -10 : 0)
         .attr("y2", config.axis_rotated ? -10 : $$.height);
 };
-c3_chart_internal_fn.generateGridData = function (type, scale) {
+ChartInternal.prototype.generateGridData = function (type, scale) {
     var $$ = this,
         gridData = [], xDomain, firstYear, lastYear, i,
         tickNum = $$.main.select("." + CLASS.axisX).selectAll('.tick').size();
@@ -249,7 +249,7 @@ c3_chart_internal_fn.generateGridData = function (type, scale) {
     }
     return gridData;
 };
-c3_chart_internal_fn.getGridFilterToRemove = function (params) {
+ChartInternal.prototype.getGridFilterToRemove = function (params) {
     return params ? function (line) {
         var found = false;
         [].concat(params).forEach(function (param) {
@@ -260,7 +260,7 @@ c3_chart_internal_fn.getGridFilterToRemove = function (params) {
         return found;
     } : function () { return true; };
 };
-c3_chart_internal_fn.removeGridLines = function (params, forX) {
+ChartInternal.prototype.removeGridLines = function (params, forX) {
     var $$ = this, config = $$.config,
         toRemove = $$.getGridFilterToRemove(params),
         toShow = function (line) { return !toRemove(line); },

src/index.js

@@ -1,7 +1,6 @@
 import { c3 } from './core';
 
 import './polyfill';
-
 import './api.axis';
 import './api.category';
 import './api.chart';

src/interaction.js

@@ -1,7 +1,7 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.initEventRect = function () {
+ChartInternal.prototype.initEventRect = function () {
     var $$ = this, config = $$.config;
 
     $$.main.select('.' + CLASS.chart).append("g")
@@ -21,7 +21,7 @@ c3_chart_internal_fn.initEventRect = function () {
         }
     }
 };
-c3_chart_internal_fn.redrawEventRect = function () {
+ChartInternal.prototype.redrawEventRect = function () {
     var $$ = this, d3 = $$.d3, config = $$.config,
         x, y, w, h;
 
@@ -140,11 +140,11 @@ c3_chart_internal_fn.redrawEventRect = function () {
             ) : function () {}
         );
 };
-c3_chart_internal_fn.getMousePosition = function (data) {
+ChartInternal.prototype.getMousePosition = function (data) {
     var $$ = this;
     return [$$.x(data.x), $$.getYScale(data.id)(data.value)];
 };
-c3_chart_internal_fn.dispatchEvent = function (type, mouse) {
+ChartInternal.prototype.dispatchEvent = function (type, mouse) {
     var $$ = this,
         selector = '.' + CLASS.eventRect,
         eventRect = $$.main.select(selector).node(),

src/legend.js

@@ -1,8 +1,8 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isDefined, isEmpty, getOption } from './util';
 
-c3_chart_internal_fn.initLegend = function () {
+ChartInternal.prototype.initLegend = function () {
     var $$ = this;
     $$.legendItemTextBox = {};
     $$.legendHasRendered = false;
@@ -16,11 +16,11 @@ c3_chart_internal_fn.initLegend = function () {
     // MEMO: translate will be upated by this, so transform not needed in updateLegend()
     $$.updateLegendWithDefaults();
 };
-c3_chart_internal_fn.updateLegendWithDefaults = function () {
+ChartInternal.prototype.updateLegendWithDefaults = function () {
     var $$ = this;
     $$.updateLegend($$.mapToIds($$.data.targets), {withTransform: false, withTransitionForTransform: false, withTransition: false});
 };
-c3_chart_internal_fn.updateSizeForLegend = function (legendHeight, legendWidth) {
+ChartInternal.prototype.updateSizeForLegend = function (legendHeight, legendWidth) {
     var $$ = this, config = $$.config, insetLegendPosition = {
         top: $$.isLegendTop ? $$.getCurrentPaddingTop() + config.legend_inset_y + 5.5 : $$.currentHeight - legendHeight - $$.getCurrentPaddingBottom() - config.legend_inset_y,
         left: $$.isLegendLeft ? $$.getCurrentPaddingLeft() + config.legend_inset_x + 0.5 : $$.currentWidth - legendWidth - $$.getCurrentPaddingRight() - config.legend_inset_x + 0.5
@@ -33,24 +33,24 @@ c3_chart_internal_fn.updateSizeForLegend = function (legendHeight, legendWidth)
         left: $$.isLegendRight ? $$.currentWidth - legendWidth : $$.isLegendInset ? insetLegendPosition.left : 0
     };
 };
-c3_chart_internal_fn.transformLegend = function (withTransition) {
+ChartInternal.prototype.transformLegend = function (withTransition) {
     var $$ = this;
     (withTransition ? $$.legend.transition() : $$.legend).attr("transform", $$.getTranslate('legend'));
 };
-c3_chart_internal_fn.updateLegendStep = function (step) {
+ChartInternal.prototype.updateLegendStep = function (step) {
     this.legendStep = step;
 };
-c3_chart_internal_fn.updateLegendItemWidth = function (w) {
+ChartInternal.prototype.updateLegendItemWidth = function (w) {
     this.legendItemWidth = w;
 };
-c3_chart_internal_fn.updateLegendItemHeight = function (h) {
+ChartInternal.prototype.updateLegendItemHeight = function (h) {
     this.legendItemHeight = h;
 };
-c3_chart_internal_fn.getLegendWidth = function () {
+ChartInternal.prototype.getLegendWidth = function () {
     var $$ = this;
     return $$.config.legend_show ? $$.isLegendRight || $$.isLegendInset ? $$.legendItemWidth * ($$.legendStep + 1) : $$.currentWidth : 0;
 };
-c3_chart_internal_fn.getLegendHeight = function () {
+ChartInternal.prototype.getLegendHeight = function () {
     var $$ = this, h = 0;
     if ($$.config.legend_show) {
         if ($$.isLegendRight) {
@@ -61,13 +61,13 @@ c3_chart_internal_fn.getLegendHeight = function () {
     }
     return h;
 };
-c3_chart_internal_fn.opacityForLegend = function (legendItem) {
+ChartInternal.prototype.opacityForLegend = function (legendItem) {
     return legendItem.classed(CLASS.legendItemHidden) ? null : 1;
 };
-c3_chart_internal_fn.opacityForUnfocusedLegend = function (legendItem) {
+ChartInternal.prototype.opacityForUnfocusedLegend = function (legendItem) {
     return legendItem.classed(CLASS.legendItemHidden) ? null : 0.3;
 };
-c3_chart_internal_fn.toggleFocusLegend = function (targetIds, focus) {
+ChartInternal.prototype.toggleFocusLegend = function (targetIds, focus) {
     var $$ = this;
     targetIds = $$.mapToTargetIds(targetIds);
     $$.legend.selectAll('.' + CLASS.legendItem)
@@ -79,14 +79,14 @@ c3_chart_internal_fn.toggleFocusLegend = function (targetIds, focus) {
             return opacity.call($$, $$.d3.select(this));
         });
 };
-c3_chart_internal_fn.revertLegend = function () {
+ChartInternal.prototype.revertLegend = function () {
     var $$ = this, d3 = $$.d3;
     $$.legend.selectAll('.' + CLASS.legendItem)
         .classed(CLASS.legendItemFocused, false)
         .transition().duration(100)
         .style('opacity', function () { return $$.opacityForLegend(d3.select(this)); });
 };
-c3_chart_internal_fn.showLegend = function (targetIds) {
+ChartInternal.prototype.showLegend = function (targetIds) {
     var $$ = this, config = $$.config;
     if (!config.legend_show) {
         config.legend_show = true;
@@ -101,7 +101,7 @@ c3_chart_internal_fn.showLegend = function (targetIds) {
         .transition()
         .style('opacity', function () { return $$.opacityForLegend($$.d3.select(this)); });
 };
-c3_chart_internal_fn.hideLegend = function (targetIds) {
+ChartInternal.prototype.hideLegend = function (targetIds) {
     var $$ = this, config = $$.config;
     if (config.legend_show && isEmpty(targetIds)) {
         config.legend_show = false;
@@ -112,10 +112,10 @@ c3_chart_internal_fn.hideLegend = function (targetIds) {
         .style('opacity', 0)
         .style('visibility', 'hidden');
 };
-c3_chart_internal_fn.clearLegendItemTextBoxCache = function () {
+ChartInternal.prototype.clearLegendItemTextBoxCache = function () {
     this.legendItemTextBox = {};
 };
-c3_chart_internal_fn.updateLegend = function (targetIds, options, transitions) {
+ChartInternal.prototype.updateLegend = function (targetIds, options, transitions) {
     var $$ = this, config = $$.config;
     var xForLegend, xForLegendText, xForLegendRect, yForLegend, yForLegendText, yForLegendRect, x1ForLegendTile, x2ForLegendTile, yForLegendTile;
     var paddingTop = 4, paddingRight = 10, maxWidth = 0, maxHeight = 0, posMin = 10, tileWidth = config.legend_item_tile_width + 5;

src/region.js

@@ -1,14 +1,14 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isValue } from './util';
 
-c3_chart_internal_fn.initRegion = function () {
+ChartInternal.prototype.initRegion = function () {
     var $$ = this;
     $$.region = $$.main.append('g')
         .attr("clip-path", $$.clipPath)
         .attr("class", CLASS.regions);
 };
-c3_chart_internal_fn.updateRegion = function (duration) {
+ChartInternal.prototype.updateRegion = function (duration) {
     var $$ = this, config = $$.config;
 
     // hide if arc type
@@ -28,7 +28,7 @@ c3_chart_internal_fn.updateRegion = function (duration) {
         .style("opacity", 0)
         .remove();
 };
-c3_chart_internal_fn.redrawRegion = function (withTransition, transition) {
+ChartInternal.prototype.redrawRegion = function (withTransition, transition) {
     var $$ = this, regions = $$.mainRegion;
     return [(withTransition ? regions.transition(transition) : regions)
             .attr("x", $$.regionX.bind($$))
@@ -38,7 +38,7 @@ c3_chart_internal_fn.redrawRegion = function (withTransition, transition) {
             .style("fill-opacity", function (d) { return isValue(d.opacity) ? d.opacity : 0.1; })
     ];
 };
-c3_chart_internal_fn.regionX = function (d) {
+ChartInternal.prototype.regionX = function (d) {
     var $$ = this, config = $$.config,
         xPos, yScale = d.axis === 'y' ? $$.y : $$.y2;
     if (d.axis === 'y' || d.axis === 'y2') {
@@ -48,7 +48,7 @@ c3_chart_internal_fn.regionX = function (d) {
     }
     return xPos;
 };
-c3_chart_internal_fn.regionY = function (d) {
+ChartInternal.prototype.regionY = function (d) {
     var $$ = this, config = $$.config,
         yPos, yScale = d.axis === 'y' ? $$.y : $$.y2;
     if (d.axis === 'y' || d.axis === 'y2') {
@@ -58,7 +58,7 @@ c3_chart_internal_fn.regionY = function (d) {
     }
     return yPos;
 };
-c3_chart_internal_fn.regionWidth = function (d) {
+ChartInternal.prototype.regionWidth = function (d) {
     var $$ = this, config = $$.config,
         start = $$.regionX(d), end, yScale = d.axis === 'y' ? $$.y : $$.y2;
     if (d.axis === 'y' || d.axis === 'y2') {
@@ -68,7 +68,7 @@ c3_chart_internal_fn.regionWidth = function (d) {
     }
     return end < start ? 0 : end - start;
 };
-c3_chart_internal_fn.regionHeight = function (d) {
+ChartInternal.prototype.regionHeight = function (d) {
     var $$ = this, config = $$.config,
         start = this.regionY(d), end, yScale = d.axis === 'y' ? $$.y : $$.y2;
     if (d.axis === 'y' || d.axis === 'y2') {
@@ -78,6 +78,6 @@ c3_chart_internal_fn.regionHeight = function (d) {
     }
     return end < start ? 0 : end - start;
 };
-c3_chart_internal_fn.isRegionOnX = function (d) {
+ChartInternal.prototype.isRegionOnX = function (d) {
     return !d.axis || d.axis === 'x';
 };

src/scale.js

@@ -1,9 +1,9 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.getScale = function (min, max, forTimeseries) {
+ChartInternal.prototype.getScale = function (min, max, forTimeseries) {
     return (forTimeseries ? this.d3.scaleTime() : this.d3.scaleLinear()).range([min, max]);
 };
-c3_chart_internal_fn.getX = function (min, max, domain, offset) {
+ChartInternal.prototype.getX = function (min, max, domain, offset) {
     var $$ = this,
         scale = $$.getScale(min, max, $$.isTimeSeries()),
         _scale = domain ? scale.domain(domain) : scale, key;
@@ -40,18 +40,18 @@ c3_chart_internal_fn.getX = function (min, max, domain, offset) {
     }
     return scale;
 };
-c3_chart_internal_fn.getY = function (min, max, domain) {
+ChartInternal.prototype.getY = function (min, max, domain) {
     var scale = this.getScale(min, max, this.isTimeSeriesY());
     if (domain) { scale.domain(domain); }
     return scale;
 };
-c3_chart_internal_fn.getYScale = function (id) {
+ChartInternal.prototype.getYScale = function (id) {
     return this.axis.getId(id) === 'y2' ? this.y2 : this.y;
 };
-c3_chart_internal_fn.getSubYScale = function (id) {
+ChartInternal.prototype.getSubYScale = function (id) {
     return this.axis.getId(id) === 'y2' ? this.subY2 : this.subY;
 };
-c3_chart_internal_fn.updateScales = function () {
+ChartInternal.prototype.updateScales = function () {
     var $$ = this, config = $$.config,
         forInit = !$$.x;
     // update edges

src/selection.js

@@ -1,7 +1,7 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.selectPoint = function (target, d, i) {
+ChartInternal.prototype.selectPoint = function (target, d, i) {
     var $$ = this, config = $$.config,
         cx = (config.axis_rotated ? $$.circleY : $$.circleX).bind($$),
         cy = (config.axis_rotated ? $$.circleX : $$.circleY).bind($$),
@@ -19,7 +19,7 @@ c3_chart_internal_fn.selectPoint = function (target, d, i) {
         .transition().duration(100)
         .attr("r", r);
 };
-c3_chart_internal_fn.unselectPoint = function (target, d, i) {
+ChartInternal.prototype.unselectPoint = function (target, d, i) {
     var $$ = this;
     $$.config.data_onunselected.call($$.api, d, target.node());
     // remove selected-circle from low layer g
@@ -27,10 +27,10 @@ c3_chart_internal_fn.unselectPoint = function (target, d, i) {
         .transition().duration(100).attr('r', 0)
         .remove();
 };
-c3_chart_internal_fn.togglePoint = function (selected, target, d, i) {
+ChartInternal.prototype.togglePoint = function (selected, target, d, i) {
     selected ? this.selectPoint(target, d, i) : this.unselectPoint(target, d, i);
 };
-c3_chart_internal_fn.selectPath = function (target, d) {
+ChartInternal.prototype.selectPath = function (target, d) {
     var $$ = this;
     $$.config.data_onselected.call($$, d, target.node());
     if ($$.config.interaction_brighten) {
@@ -38,7 +38,7 @@ c3_chart_internal_fn.selectPath = function (target, d) {
             .style("fill", function () { return $$.d3.rgb($$.color(d)).brighter(0.75); });
     }
 };
-c3_chart_internal_fn.unselectPath = function (target, d) {
+ChartInternal.prototype.unselectPath = function (target, d) {
     var $$ = this;
     $$.config.data_onunselected.call($$, d, target.node());
     if ($$.config.interaction_brighten) {
@@ -46,10 +46,10 @@ c3_chart_internal_fn.unselectPath = function (target, d) {
             .style("fill", function () { return $$.color(d); });
     }
 };
-c3_chart_internal_fn.togglePath = function (selected, target, d, i) {
+ChartInternal.prototype.togglePath = function (selected, target, d, i) {
     selected ? this.selectPath(target, d, i) : this.unselectPath(target, d, i);
 };
-c3_chart_internal_fn.getToggle = function (that, d) {
+ChartInternal.prototype.getToggle = function (that, d) {
     var $$ = this, toggle;
     if (that.nodeName === 'circle') {
         if ($$.isStepType(d)) {
@@ -64,7 +64,7 @@ c3_chart_internal_fn.getToggle = function (that, d) {
     }
     return toggle;
 };
-c3_chart_internal_fn.toggleShape = function (that, d, i) {
+ChartInternal.prototype.toggleShape = function (that, d, i) {
     var $$ = this, d3 = $$.d3, config = $$.config,
         shape = d3.select(that), isSelected = shape.classed(CLASS.SELECTED),
         toggle = $$.getToggle(that, d).bind($$);

src/shape.bar.js

@@ -1,13 +1,13 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isValue } from './util';
 
-c3_chart_internal_fn.initBar = function () {
+ChartInternal.prototype.initBar = function () {
     var $$ = this;
     $$.main.select('.' + CLASS.chart).append("g")
         .attr("class", CLASS.chartBars);
 };
-c3_chart_internal_fn.updateTargetsForBar = function (targets) {
+ChartInternal.prototype.updateTargetsForBar = function (targets) {
     var $$ = this, config = $$.config,
         mainBars, mainBarEnter,
         classChartBar = $$.classChartBar.bind($$),
@@ -25,7 +25,7 @@ c3_chart_internal_fn.updateTargetsForBar = function (targets) {
         .style("cursor", function (d) { return config.data_selection_isselectable(d) ? "pointer" : null; });
 
 };
-c3_chart_internal_fn.updateBar = function (durationForExit) {
+ChartInternal.prototype.updateBar = function (durationForExit) {
     var $$ = this,
         barData = $$.barData.bind($$),
         classBar = $$.classBar.bind($$),
@@ -42,7 +42,7 @@ c3_chart_internal_fn.updateBar = function (durationForExit) {
     mainBar.exit().transition().duration(durationForExit)
         .style("opacity", 0);
 };
-c3_chart_internal_fn.redrawBar = function (drawBar, withTransition, transition) {
+ChartInternal.prototype.redrawBar = function (drawBar, withTransition, transition) {
     return [
         (withTransition ? this.mainBar.transition(transition) : this.mainBar)
             .attr('d', drawBar)
@@ -51,25 +51,25 @@ c3_chart_internal_fn.redrawBar = function (drawBar, withTransition, transition)
             .style("opacity", 1)
     ];
 };
-c3_chart_internal_fn.getBarW = function (axis, barTargetsNum) {
+ChartInternal.prototype.getBarW = function (axis, barTargetsNum) {
     var $$ = this, config = $$.config,
         w = typeof config.bar_width === 'number' ? config.bar_width : barTargetsNum ? (axis.tickInterval() * config.bar_width_ratio) / barTargetsNum : 0;
     return config.bar_width_max && w > config.bar_width_max ? config.bar_width_max : w;
 };
-c3_chart_internal_fn.getBars = function (i, id) {
+ChartInternal.prototype.getBars = function (i, id) {
     var $$ = this;
     return (id ? $$.main.selectAll('.' + CLASS.bars + $$.getTargetSelectorSuffix(id)) : $$.main).selectAll('.' + CLASS.bar + (isValue(i) ? '-' + i : ''));
 };
-c3_chart_internal_fn.expandBars = function (i, id, reset) {
+ChartInternal.prototype.expandBars = function (i, id, reset) {
     var $$ = this;
     if (reset) { $$.unexpandBars(); }
     $$.getBars(i, id).classed(CLASS.EXPANDED, true);
 };
-c3_chart_internal_fn.unexpandBars = function (i) {
+ChartInternal.prototype.unexpandBars = function (i) {
     var $$ = this;
     $$.getBars(i).classed(CLASS.EXPANDED, false);
 };
-c3_chart_internal_fn.generateDrawBar = function (barIndices, isSub) {
+ChartInternal.prototype.generateDrawBar = function (barIndices, isSub) {
     var $$ = this, config = $$.config,
         getPoints = $$.generateGetBarPoints(barIndices, isSub);
     return function (d, i) {
@@ -89,7 +89,7 @@ c3_chart_internal_fn.generateDrawBar = function (barIndices, isSub) {
         return path;
     };
 };
-c3_chart_internal_fn.generateGetBarPoints = function (barIndices, isSub) {
+ChartInternal.prototype.generateGetBarPoints = function (barIndices, isSub) {
     var $$ = this,
         axis = isSub ? $$.subXAxis : $$.xAxis,
         barTargetsNum = barIndices.__max__ + 1,
@@ -116,7 +116,7 @@ c3_chart_internal_fn.generateGetBarPoints = function (barIndices, isSub) {
         ];
     };
 };
-c3_chart_internal_fn.isWithinBar = function (mouse, that) {
+ChartInternal.prototype.isWithinBar = function (mouse, that) {
     var box = that.getBoundingClientRect(),
         seg0 = that.pathSegList.getItem(0), seg1 = that.pathSegList.getItem(1),
         x = Math.min(seg0.x, seg1.x), y = Math.min(seg0.y, seg1.y),

src/shape.js

@@ -1,8 +1,8 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isUndefined } from './util';
 
-c3_chart_internal_fn.getShapeIndices = function (typeFilter) {
+ChartInternal.prototype.getShapeIndices = function (typeFilter) {
     var $$ = this, config = $$.config,
         indices = {}, i = 0, j, k;
     $$.filterTargetsToShow($$.data.targets.filter(typeFilter, $$)).forEach(function (d) {
@@ -20,21 +20,21 @@ c3_chart_internal_fn.getShapeIndices = function (typeFilter) {
     indices.__max__ = i - 1;
     return indices;
 };
-c3_chart_internal_fn.getShapeX = function (offset, targetsNum, indices, isSub) {
+ChartInternal.prototype.getShapeX = function (offset, targetsNum, indices, isSub) {
     var $$ = this, scale = isSub ? $$.subX : $$.x;
     return function (d) {
         var index = d.id in indices ? indices[d.id] : 0;
         return d.x || d.x === 0 ? scale(d.x) - offset * (targetsNum / 2 - index) : 0;
     };
 };
-c3_chart_internal_fn.getShapeY = function (isSub) {
+ChartInternal.prototype.getShapeY = function (isSub) {
     var $$ = this;
     return function (d) {
         var scale = isSub ? $$.getSubYScale(d.id) : $$.getYScale(d.id);
         return scale(d.value);
     };
 };
-c3_chart_internal_fn.getShapeOffset = function (typeFilter, indices, isSub) {
+ChartInternal.prototype.getShapeOffset = function (typeFilter, indices, isSub) {
     var $$ = this,
         targets = $$.orderTargets($$.filterTargetsToShow($$.data.targets.filter(typeFilter, $$))),
         targetIds = targets.map(function (t) { return t.id; });
@@ -63,7 +63,7 @@ c3_chart_internal_fn.getShapeOffset = function (typeFilter, indices, isSub) {
         return offset;
     };
 };
-c3_chart_internal_fn.isWithinShape = function (that, d) {
+ChartInternal.prototype.isWithinShape = function (that, d) {
     var $$ = this,
         shape = $$.d3.select(that), isWithin;
     if (!$$.isTargetToShow(d.id)) {
@@ -79,7 +79,7 @@ c3_chart_internal_fn.isWithinShape = function (that, d) {
 };
 
 
-c3_chart_internal_fn.getInterpolate = function (d) {
+ChartInternal.prototype.getInterpolate = function (d) {
     var $$ = this, d3 = $$.d3,
         types = {
             'linear': d3.curveLinear,

src/shape.line.js

@@ -1,13 +1,13 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isValue, isFunction, isUndefined, isDefined } from './util';
 
-c3_chart_internal_fn.initLine = function () {
+ChartInternal.prototype.initLine = function () {
     var $$ = this;
     $$.main.select('.' + CLASS.chart).append("g")
         .attr("class", CLASS.chartLines);
 };
-c3_chart_internal_fn.updateTargetsForLine = function (targets) {
+ChartInternal.prototype.updateTargetsForLine = function (targets) {
     var $$ = this, config = $$.config,
         mainLines, mainLineEnter,
         classChartLine = $$.classChartLine.bind($$),
@@ -43,7 +43,7 @@ c3_chart_internal_fn.updateTargetsForLine = function (targets) {
     // MEMO: can not keep same color...
     //mainLineUpdate.exit().remove();
 };
-c3_chart_internal_fn.updateLine = function (durationForExit) {
+ChartInternal.prototype.updateLine = function (durationForExit) {
     var $$ = this;
     var mainLine = $$.main.selectAll('.' + CLASS.lines).selectAll('.' + CLASS.line)
         .data($$.lineData.bind($$));
@@ -57,7 +57,7 @@ c3_chart_internal_fn.updateLine = function (durationForExit) {
     mainLine.exit().transition().duration(durationForExit)
         .style('opacity', 0);
 };
-c3_chart_internal_fn.redrawLine = function (drawLine, withTransition, transition) {
+ChartInternal.prototype.redrawLine = function (drawLine, withTransition, transition) {
     return [
         (withTransition ? this.mainLine.transition(transition) : this.mainLine)
             .attr("d", drawLine)
@@ -65,7 +65,7 @@ c3_chart_internal_fn.redrawLine = function (drawLine, withTransition, transition
             .style("opacity", 1)
     ];
 };
-c3_chart_internal_fn.generateDrawLine = function (lineIndices, isSub) {
+ChartInternal.prototype.generateDrawLine = function (lineIndices, isSub) {
     var $$ = this, config = $$.config,
         line = $$.d3.line(),
         getPoints = $$.generateGetLinePoints(lineIndices, isSub),
@@ -97,7 +97,7 @@ c3_chart_internal_fn.generateDrawLine = function (lineIndices, isSub) {
         return path ? path : "M 0 0";
     };
 };
-c3_chart_internal_fn.generateGetLinePoints = function (lineIndices, isSub) { // partial duplication of generateGetBarPoints
+ChartInternal.prototype.generateGetLinePoints = function (lineIndices, isSub) { // partial duplication of generateGetBarPoints
     var $$ = this, config = $$.config,
         lineTargetsNum = lineIndices.__max__ + 1,
         x = $$.getShapeX(0, lineTargetsNum, lineIndices, !!isSub),
@@ -123,7 +123,7 @@ c3_chart_internal_fn.generateGetLinePoints = function (lineIndices, isSub) { //
 };
 
 
-c3_chart_internal_fn.lineWithRegions = function (d, x, y, _regions) {
+ChartInternal.prototype.lineWithRegions = function (d, x, y, _regions) {
     var $$ = this, config = $$.config,
         prev = -1, i, j,
         s = "M", sWithRegion,
@@ -219,7 +219,7 @@ c3_chart_internal_fn.lineWithRegions = function (d, x, y, _regions) {
 };
 
 
-c3_chart_internal_fn.updateArea = function (durationForExit) {
+ChartInternal.prototype.updateArea = function (durationForExit) {
     var $$ = this, d3 = $$.d3;
     var mainArea = $$.main.selectAll('.' + CLASS.areas).selectAll('.' + CLASS.area)
         .data($$.lineData.bind($$));
@@ -232,7 +232,7 @@ c3_chart_internal_fn.updateArea = function (durationForExit) {
     mainArea.exit().transition().duration(durationForExit)
         .style('opacity', 0);
 };
-c3_chart_internal_fn.redrawArea = function (drawArea, withTransition, transition) {
+ChartInternal.prototype.redrawArea = function (drawArea, withTransition, transition) {
     return [
         (withTransition ? this.mainArea.transition(transition) : this.mainArea)
             .attr("d", drawArea)
@@ -240,7 +240,7 @@ c3_chart_internal_fn.redrawArea = function (drawArea, withTransition, transition
             .style("opacity", this.orgAreaOpacity)
     ];
 };
-c3_chart_internal_fn.generateDrawArea = function (areaIndices, isSub) {
+ChartInternal.prototype.generateDrawArea = function (areaIndices, isSub) {
     var $$ = this, config = $$.config, area = $$.d3.area(),
         getPoints = $$.generateGetAreaPoints(areaIndices, isSub),
         yScaleGetter = isSub ? $$.getSubYScale : $$.getYScale,
@@ -273,10 +273,10 @@ c3_chart_internal_fn.generateDrawArea = function (areaIndices, isSub) {
         return path ? path : "M 0 0";
     };
 };
-c3_chart_internal_fn.getAreaBaseValue = function () {
+ChartInternal.prototype.getAreaBaseValue = function () {
     return 0;
 };
-c3_chart_internal_fn.generateGetAreaPoints = function (areaIndices, isSub) { // partial duplication of generateGetBarPoints
+ChartInternal.prototype.generateGetAreaPoints = function (areaIndices, isSub) { // partial duplication of generateGetBarPoints
     var $$ = this, config = $$.config,
         areaTargetsNum = areaIndices.__max__ + 1,
         x = $$.getShapeX(0, areaTargetsNum, areaIndices, !!isSub),
@@ -302,7 +302,7 @@ c3_chart_internal_fn.generateGetAreaPoints = function (areaIndices, isSub) { //
 };
 
 
-c3_chart_internal_fn.updateCircle = function (cx, cy) {
+ChartInternal.prototype.updateCircle = function (cx, cy) {
     var $$ = this;
     var mainCircle = $$.main.selectAll('.' + CLASS.circles).selectAll('.' + CLASS.circle)
         .data($$.lineOrScatterData.bind($$));
@@ -317,7 +317,7 @@ c3_chart_internal_fn.updateCircle = function (cx, cy) {
     mainCircle.exit()
         .style("opacity", 0);
 };
-c3_chart_internal_fn.redrawCircle = function (cx, cy, withTransition, transition) {
+ChartInternal.prototype.redrawCircle = function (cx, cy, withTransition, transition) {
     var $$ = this,
         selectedCircles = $$.main.selectAll('.' + CLASS.selectedCircle);
     return [
@@ -331,10 +331,10 @@ c3_chart_internal_fn.redrawCircle = function (cx, cy, withTransition, transition
             .attr("cy", cy)
     ];
 };
-c3_chart_internal_fn.circleX = function (d) {
+ChartInternal.prototype.circleX = function (d) {
     return d.x || d.x === 0 ? this.x(d.x) : null;
 };
-c3_chart_internal_fn.updateCircleY = function () {
+ChartInternal.prototype.updateCircleY = function () {
     var $$ = this, lineIndices, getPoints;
     if ($$.config.data_groups.length > 0) {
         lineIndices = $$.getShapeIndices($$.isLineType),
@@ -348,11 +348,11 @@ c3_chart_internal_fn.updateCircleY = function () {
         };
     }
 };
-c3_chart_internal_fn.getCircles = function (i, id) {
+ChartInternal.prototype.getCircles = function (i, id) {
     var $$ = this;
     return (id ? $$.main.selectAll('.' + CLASS.circles + $$.getTargetSelectorSuffix(id)) : $$.main).selectAll('.' + CLASS.circle + (isValue(i) ? '-' + i : ''));
 };
-c3_chart_internal_fn.expandCircles = function (i, id, reset) {
+ChartInternal.prototype.expandCircles = function (i, id, reset) {
     var $$ = this,
         r = $$.pointExpandedR.bind($$);
     if (reset) { $$.unexpandCircles(); }
@@ -360,7 +360,7 @@ c3_chart_internal_fn.expandCircles = function (i, id, reset) {
         .classed(CLASS.EXPANDED, true)
         .attr('r', r);
 };
-c3_chart_internal_fn.unexpandCircles = function (i) {
+ChartInternal.prototype.unexpandCircles = function (i) {
     var $$ = this,
         r = $$.pointR.bind($$);
     $$.getCircles(i)
@@ -368,11 +368,11 @@ c3_chart_internal_fn.unexpandCircles = function (i) {
         .classed(CLASS.EXPANDED, false)
         .attr('r', r);
 };
-c3_chart_internal_fn.pointR = function (d) {
+ChartInternal.prototype.pointR = function (d) {
     var $$ = this, config = $$.config;
     return $$.isStepType(d) ? 0 : (isFunction(config.point_r) ? config.point_r(d) : config.point_r);
 };
-c3_chart_internal_fn.pointExpandedR = function (d) {
+ChartInternal.prototype.pointExpandedR = function (d) {
     var $$ = this, config = $$.config;
     if (config.point_focus_expand_enabled) {
         return isFunction(config.point_focus_expand_r) ? config.point_focus_expand_r(d) : ((config.point_focus_expand_r) ? config.point_focus_expand_r : $$.pointR(d) * 1.75);
@@ -380,16 +380,16 @@ c3_chart_internal_fn.pointExpandedR = function (d) {
         return $$.pointR(d);
     }
 };
-c3_chart_internal_fn.pointSelectR = function (d) {
+ChartInternal.prototype.pointSelectR = function (d) {
     var $$ = this, config = $$.config;
     return isFunction(config.point_select_r) ? config.point_select_r(d) : ((config.point_select_r) ? config.point_select_r : $$.pointR(d) * 4);
 };
-c3_chart_internal_fn.isWithinCircle = function (that, r) {
+ChartInternal.prototype.isWithinCircle = function (that, r) {
     var d3 = this.d3,
         mouse = d3.mouse(that), d3_this = d3.select(that),
         cx = +d3_this.attr("cx"), cy = +d3_this.attr("cy");
     return Math.sqrt(Math.pow(cx - mouse[0], 2) + Math.pow(cy - mouse[1], 2)) < r;
 };
-c3_chart_internal_fn.isWithinStep = function (that, y) {
+ChartInternal.prototype.isWithinStep = function (that, y) {
     return Math.abs(y - this.d3.mouse(that)[1]) < 30;
 };

src/size.js

@@ -1,17 +1,17 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isValue, ceil10 } from './util';
 
-c3_chart_internal_fn.getCurrentWidth = function () {
+ChartInternal.prototype.getCurrentWidth = function () {
     var $$ = this, config = $$.config;
     return config.size_width ? config.size_width : $$.getParentWidth();
 };
-c3_chart_internal_fn.getCurrentHeight = function () {
+ChartInternal.prototype.getCurrentHeight = function () {
     var $$ = this, config = $$.config,
         h = config.size_height ? config.size_height : $$.getParentHeight();
     return h > 0 ? h : 320 / ($$.hasType('gauge') && !config.gauge_fullCircle ? 2 : 1);
 };
-c3_chart_internal_fn.getCurrentPaddingTop = function () {
+ChartInternal.prototype.getCurrentPaddingTop = function () {
     var $$ = this,
         config = $$.config,
         padding = isValue(config.padding_top) ? config.padding_top : 0;
@@ -20,11 +20,11 @@ c3_chart_internal_fn.getCurrentPaddingTop = function () {
     }
     return padding;
 };
-c3_chart_internal_fn.getCurrentPaddingBottom = function () {
+ChartInternal.prototype.getCurrentPaddingBottom = function () {
     var config = this.config;
     return isValue(config.padding_bottom) ? config.padding_bottom : 0;
 };
-c3_chart_internal_fn.getCurrentPaddingLeft = function (withoutRecompute) {
+ChartInternal.prototype.getCurrentPaddingLeft = function (withoutRecompute) {
     var $$ = this, config = $$.config;
     if (isValue(config.padding_left)) {
         return config.padding_left;
@@ -36,7 +36,7 @@ c3_chart_internal_fn.getCurrentPaddingLeft = function (withoutRecompute) {
         return ceil10($$.getAxisWidthByAxisId('y', withoutRecompute));
     }
 };
-c3_chart_internal_fn.getCurrentPaddingRight = function () {
+ChartInternal.prototype.getCurrentPaddingRight = function () {
     var $$ = this, config = $$.config,
         defaultPadding = 10, legendWidthOnRight = $$.isLegendRight ? $$.getLegendWidth() + 20 : 0;
     if (isValue(config.padding_right)) {
@@ -50,7 +50,7 @@ c3_chart_internal_fn.getCurrentPaddingRight = function () {
     }
 };
 
-c3_chart_internal_fn.getParentRectValue = function (key) {
+ChartInternal.prototype.getParentRectValue = function (key) {
     var parent = this.selectChart.node(), v;
     while (parent && parent.tagName !== 'BODY') {
         try {
@@ -69,16 +69,16 @@ c3_chart_internal_fn.getParentRectValue = function (key) {
     }
     return v;
 };
-c3_chart_internal_fn.getParentWidth = function () {
+ChartInternal.prototype.getParentWidth = function () {
     return this.getParentRectValue('width');
 };
-c3_chart_internal_fn.getParentHeight = function () {
+ChartInternal.prototype.getParentHeight = function () {
     var h = this.selectChart.style('height');
     return h.indexOf('px') > 0 ? +h.replace('px', '') : 0;
 };
 
 
-c3_chart_internal_fn.getSvgLeft = function (withoutRecompute) {
+ChartInternal.prototype.getSvgLeft = function (withoutRecompute) {
     var $$ = this, config = $$.config,
         hasLeftAxisRect = config.axis_rotated || (!config.axis_rotated && !config.axis_y_inner),
         leftAxisClass = config.axis_rotated ? CLASS.axisX : CLASS.axisY,
@@ -91,11 +91,11 @@ c3_chart_internal_fn.getSvgLeft = function (withoutRecompute) {
 };
 
 
-c3_chart_internal_fn.getAxisWidthByAxisId = function (id, withoutRecompute) {
+ChartInternal.prototype.getAxisWidthByAxisId = function (id, withoutRecompute) {
     var $$ = this, position = $$.axis.getLabelPositionById(id);
     return $$.axis.getMaxTickWidth(id, withoutRecompute) + (position.isInner ? 20 : 40);
 };
-c3_chart_internal_fn.getHorizontalAxisHeight = function (axisId) {
+ChartInternal.prototype.getHorizontalAxisHeight = function (axisId) {
     var $$ = this, config = $$.config, h = 30;
     if (axisId === 'x' && !config.axis_x_show) { return 8; }
     if (axisId === 'x' && config.axis_x_height) { return config.axis_x_height; }

src/subchart.js

@@ -1,8 +1,8 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isFunction } from './util';
 
-c3_chart_internal_fn.initBrush = function (scale) {
+ChartInternal.prototype.initBrush = function (scale) {
     var $$ = this, d3 = $$.d3;
     // TODO: dynamically change brushY/brushX according to axis_rotated.
     $$.brush = ($$.config.axis_rotated ? d3.brushY() : d3.brushX()).on("brush", function () {
@@ -59,7 +59,7 @@ c3_chart_internal_fn.initBrush = function (scale) {
     };
     return $$.brush.updateScale(scale);
 };
-c3_chart_internal_fn.initSubchart = function () {
+ChartInternal.prototype.initSubchart = function () {
     var $$ = this, config = $$.config,
         context = $$.context = $$.svg.append("g").attr("transform", $$.getTranslate('context')),
         visibility = config.subchart_show ? 'visible' : 'hidden';
@@ -92,13 +92,13 @@ c3_chart_internal_fn.initSubchart = function () {
         .attr("transform", $$.getTranslate('subx'))
         .attr("clip-path", config.axis_rotated ? "" : $$.clipPathForXAxis);
 };
-c3_chart_internal_fn.initSubchartBrush = function () {
+ChartInternal.prototype.initSubchartBrush = function () {
     var $$ = this;
     // Add extent rect for Brush
     $$.initBrush($$.subX).updateExtent();
     $$.context.select('.' + CLASS.brush).call($$.brush);
 };
-c3_chart_internal_fn.updateTargetsForSubchart = function (targets) {
+ChartInternal.prototype.updateTargetsForSubchart = function (targets) {
     var $$ = this, context = $$.context, config = $$.config,
         contextLineEnter, contextLine, contextBarEnter, contextBar,
         classChartBar = $$.classChartBar.bind($$),
@@ -138,7 +138,7 @@ c3_chart_internal_fn.updateTargetsForSubchart = function (targets) {
             .attr(config.axis_rotated ? "width" : "height", config.axis_rotated ? $$.width2 : $$.height2);
     }
 };
-c3_chart_internal_fn.updateBarForSubchart = function (durationForExit) {
+ChartInternal.prototype.updateBarForSubchart = function (durationForExit) {
     var $$ = this;
     var contextBar = $$.context.selectAll('.' + CLASS.bars).selectAll('.' + CLASS.bar)
         .data($$.barData.bind($$));
@@ -152,12 +152,12 @@ c3_chart_internal_fn.updateBarForSubchart = function (durationForExit) {
     $$.contextBar = contextBarEnter.merge(contextBar)
         .style("opacity", $$.initialOpacity.bind($$));
 };
-c3_chart_internal_fn.redrawBarForSubchart = function (drawBarOnSub, withTransition, duration) {
+ChartInternal.prototype.redrawBarForSubchart = function (drawBarOnSub, withTransition, duration) {
     (withTransition ? this.contextBar.transition(Math.random().toString()).duration(duration) : this.contextBar)
         .attr('d', drawBarOnSub)
         .style('opacity', 1);
 };
-c3_chart_internal_fn.updateLineForSubchart = function (durationForExit) {
+ChartInternal.prototype.updateLineForSubchart = function (durationForExit) {
     var $$ = this;
     var contextLine = $$.context.selectAll('.' + CLASS.lines).selectAll('.' + CLASS.line)
         .data($$.lineData.bind($$));
@@ -170,12 +170,12 @@ c3_chart_internal_fn.updateLineForSubchart = function (durationForExit) {
     $$.contextLine = contextLineEnter.merge(contextLine)
         .style("opacity", $$.initialOpacity.bind($$));
 };
-c3_chart_internal_fn.redrawLineForSubchart = function (drawLineOnSub, withTransition, duration) {
+ChartInternal.prototype.redrawLineForSubchart = function (drawLineOnSub, withTransition, duration) {
     (withTransition ? this.contextLine.transition(Math.random().toString()).duration(duration) : this.contextLine)
         .attr("d", drawLineOnSub)
         .style('opacity', 1);
 };
-c3_chart_internal_fn.updateAreaForSubchart = function (durationForExit) {
+ChartInternal.prototype.updateAreaForSubchart = function (durationForExit) {
     var $$ = this, d3 = $$.d3;
     var contextArea = $$.context.selectAll('.' + CLASS.areas).selectAll('.' + CLASS.area)
         .data($$.lineData.bind($$));
@@ -189,13 +189,13 @@ c3_chart_internal_fn.updateAreaForSubchart = function (durationForExit) {
     $$.contextArea = contextAreaEnter.merge(contextArea)
         .style("opacity", 0);
 };
-c3_chart_internal_fn.redrawAreaForSubchart = function (drawAreaOnSub, withTransition, duration) {
+ChartInternal.prototype.redrawAreaForSubchart = function (drawAreaOnSub, withTransition, duration) {
     (withTransition ? this.contextArea.transition(Math.random().toString()).duration(duration) : this.contextArea)
         .attr("d", drawAreaOnSub)
         .style("fill", this.color)
         .style("opacity", this.orgAreaOpacity);
 };
-c3_chart_internal_fn.redrawSubchart = function (withSubchart, transitions, duration, durationForExit, areaIndices, barIndices, lineIndices) {
+ChartInternal.prototype.redrawSubchart = function (withSubchart, transitions, duration, durationForExit, areaIndices, barIndices, lineIndices) {
     var $$ = this, d3 = $$.d3, config = $$.config,
         drawAreaOnSub, drawBarOnSub, drawLineOnSub;
 
@@ -228,7 +228,7 @@ c3_chart_internal_fn.redrawSubchart = function (withSubchart, transitions, durat
         }
     }
 };
-c3_chart_internal_fn.redrawForBrush = function () {
+ChartInternal.prototype.redrawForBrush = function () {
     var $$ = this, x = $$.x, d3 = $$.d3, s;
     $$.redraw({
         withTransition: false,
@@ -245,7 +245,7 @@ c3_chart_internal_fn.redrawForBrush = function () {
                                                .translate(-s[0], 0));
     $$.config.subchart_onbrush.call($$.api, x.orgDomain());
 };
-c3_chart_internal_fn.transformContext = function (withTransition, transitions) {
+ChartInternal.prototype.transformContext = function (withTransition, transitions) {
     var $$ = this, subXAxis;
     if (transitions && transitions.axisSubX) {
         subXAxis = transitions.axisSubX;
@@ -256,7 +256,7 @@ c3_chart_internal_fn.transformContext = function (withTransition, transitions) {
     $$.context.attr("transform", $$.getTranslate('context'));
     subXAxis.attr("transform", $$.getTranslate('subx'));
 };
-c3_chart_internal_fn.getDefaultSelection = function () {
+ChartInternal.prototype.getDefaultSelection = function () {
     var $$ = this, config = $$.config,
         selection = isFunction(config.axis_x_selection) ? config.axis_x_selection($$.getXDomain($$.data.targets)) : config.axis_x_selection;
     if ($$.isTimeSeries()) {

src/text.js

@@ -1,13 +1,13 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.initText = function () {
+ChartInternal.prototype.initText = function () {
     var $$ = this;
     $$.main.select('.' + CLASS.chart).append("g")
         .attr("class", CLASS.chartTexts);
     $$.mainText = $$.d3.selectAll([]);
 };
-c3_chart_internal_fn.updateTargetsForText = function (targets) {
+ChartInternal.prototype.updateTargetsForText = function (targets) {
     var $$ = this,
         classChartText = $$.classChartText.bind($$),
         classTexts = $$.classTexts.bind($$),
@@ -23,7 +23,7 @@ c3_chart_internal_fn.updateTargetsForText = function (targets) {
     mainTextEnter.merge(mainText)
         .attr('class', function (d) { return classChartText(d) + classFocus(d); });
 };
-c3_chart_internal_fn.updateText = function (xForText, yForText, durationForExit) {
+ChartInternal.prototype.updateText = function (xForText, yForText, durationForExit) {
     var $$ = this, config = $$.config,
         barOrLineData = $$.barOrLineData.bind($$),
         classText = $$.classText.bind($$);
@@ -44,7 +44,7 @@ c3_chart_internal_fn.updateText = function (xForText, yForText, durationForExit)
         .style('fill-opacity', 0)
         .remove();
 };
-c3_chart_internal_fn.redrawText = function (xForText, yForText, forFlow, withTransition, transition) {
+ChartInternal.prototype.redrawText = function (xForText, yForText, forFlow, withTransition, transition) {
     return [
         (withTransition ? this.mainText.transition(transition) : this.mainText)
             .attr('x', xForText)
@@ -53,7 +53,7 @@ c3_chart_internal_fn.redrawText = function (xForText, yForText, forFlow, withTra
             .style("fill-opacity", forFlow ? 0 : this.opacityForText.bind(this))
     ];
 };
-c3_chart_internal_fn.getTextRect = function (text, cls, element) {
+ChartInternal.prototype.getTextRect = function (text, cls, element) {
     var dummy = this.d3.select('body').append('div').classed('c3', true),
         svg = dummy.append("svg").style('visibility', 'hidden').style('position', 'fixed').style('top', 0).style('left', 0),
         font = this.d3.select(element).style('font'),
@@ -68,7 +68,7 @@ c3_chart_internal_fn.getTextRect = function (text, cls, element) {
     dummy.remove();
     return rect;
 };
-c3_chart_internal_fn.generateXYForText = function (areaIndices, barIndices, lineIndices, forX) {
+ChartInternal.prototype.generateXYForText = function (areaIndices, barIndices, lineIndices, forX) {
     var $$ = this,
         getAreaPoints = $$.generateGetAreaPoints(areaIndices, false),
         getBarPoints = $$.generateGetBarPoints(barIndices, false),
@@ -79,7 +79,7 @@ c3_chart_internal_fn.generateXYForText = function (areaIndices, barIndices, line
         return getter.call($$, getPoints(d, i), d, this);
     };
 };
-c3_chart_internal_fn.getXForText = function (points, d, textElement) {
+ChartInternal.prototype.getXForText = function (points, d, textElement) {
     var $$ = this,
         box = textElement.getBoundingClientRect(), xPos, padding;
     if ($$.config.axis_rotated) {
@@ -98,7 +98,7 @@ c3_chart_internal_fn.getXForText = function (points, d, textElement) {
     }
     return xPos;
 };
-c3_chart_internal_fn.getYForText = function (points, d, textElement) {
+ChartInternal.prototype.getYForText = function (points, d, textElement) {
     var $$ = this,
         box = textElement.getBoundingClientRect(),
         yPos;

src/title.js

@@ -1,19 +1,24 @@
-import { c3_chart_internal_fn } from './core';
+import {
+    ChartInternal
+} from './core';
 
-c3_chart_internal_fn.initTitle = function () {
+ChartInternal.prototype.initTitle = function () {
     var $$ = this;
     $$.title = $$.svg.append("text")
-          .text($$.config.title_text)
-          .attr("class", $$.CLASS.title);
+        .text($$.config.title_text)
+        .attr("class", $$.CLASS.title);
 };
-c3_chart_internal_fn.redrawTitle = function () {
+ChartInternal.prototype.redrawTitle = function () {
     var $$ = this;
     $$.title
-          .attr("x", $$.xForTitle.bind($$))
-          .attr("y", $$.yForTitle.bind($$));
+        .attr("x", $$.xForTitle.bind($$))
+        .attr("y", $$.yForTitle.bind($$));
 };
-c3_chart_internal_fn.xForTitle = function () {
-    var $$ = this, config = $$.config, position = config.title_position || 'left', x;
+ChartInternal.prototype.xForTitle = function () {
+    var $$ = this,
+        config = $$.config,
+        position = config.title_position || 'left',
+        x;
     if (position.indexOf('right') >= 0) {
         x = $$.currentWidth - $$.getTextRect($$.title.node().textContent, $$.CLASS.title, $$.title.node()).width - config.title_padding.right;
     } else if (position.indexOf('center') >= 0) {
@@ -23,11 +28,11 @@ c3_chart_internal_fn.xForTitle = function () {
     }
     return x;
 };
-c3_chart_internal_fn.yForTitle = function () {
+ChartInternal.prototype.yForTitle = function () {
     var $$ = this;
     return $$.config.title_padding.top + $$.getTextRect($$.title.node().textContent, $$.CLASS.title, $$.title.node()).height;
 };
-c3_chart_internal_fn.getTitlePadding = function() {
+ChartInternal.prototype.getTitlePadding = function () {
     var $$ = this;
     return $$.yForTitle() + $$.config.title_padding.bottom;
 };

src/tooltip.js

@@ -1,12 +1,22 @@
 import CLASS from './class';
-import { c3_chart_internal_fn } from './core';
-import { isValue, isFunction, isArray, isString, sanitise } from './util';
-
-c3_chart_internal_fn.initTooltip = function () {
-    var $$ = this, config = $$.config, i;
+import {
+    ChartInternal
+} from './core';
+import {
+    isValue,
+    isFunction,
+    isArray,
+    isString,
+    sanitise
+} from './util';
+
+ChartInternal.prototype.initTooltip = function () {
+    var $$ = this,
+        config = $$.config,
+        i;
     $$.tooltip = $$.selectChart
         .style("position", "relative")
-      .append("div")
+        .append("div")
         .attr('class', CLASS.tooltipContainer)
         .style("position", "absolute")
         .style("pointer-events", "none")
@@ -16,7 +26,9 @@ c3_chart_internal_fn.initTooltip = function () {
         if ($$.isTimeSeries() && isString(config.tooltip_init_x)) {
             config.tooltip_init_x = $$.parseDate(config.tooltip_init_x);
             for (i = 0; i < $$.data.targets[0].values.length; i++) {
-                if (($$.data.targets[0].values[i].x - config.tooltip_init_x) === 0) { break; }
+                if (($$.data.targets[0].values[i].x - config.tooltip_init_x) === 0) {
+                    break;
+                }
             }
             config.tooltip_init_x = i;
         }
@@ -28,8 +40,9 @@ c3_chart_internal_fn.initTooltip = function () {
             .style("display", "block");
     }
 };
-c3_chart_internal_fn.getTooltipSortFunction = function() {
-    var $$ = this, config = $$.config;
+ChartInternal.prototype.getTooltipSortFunction = function () {
+    var $$ = this,
+        config = $$.config;
 
     if (config.data_groups.length === 0 || config.tooltip_order !== undefined) {
         // if data are not grouped or if an order is specified
@@ -40,13 +53,13 @@ c3_chart_internal_fn.getTooltipSortFunction = function() {
             order = config.data_order;
         }
 
-        var valueOf = function(obj) {
+        var valueOf = function (obj) {
             return obj ? obj.value : null;
         };
 
         // if data are not grouped, we sort them by their value
         if (isString(order) && order.toLowerCase() === 'asc') {
-            return function(a, b) {
+            return function (a, b) {
                 return valueOf(a) - valueOf(b);
             };
         } else if (isString(order) && order.toLowerCase() === 'desc') {
@@ -65,10 +78,10 @@ c3_chart_internal_fn.getTooltipSortFunction = function() {
                 sortFunction = function (a, b) {
                     return order(a ? {
                         id: a.id,
-                        values: [ a ]
+                        values: [a]
                     } : null, b ? {
                         id: b.id,
-                        values: [ b ]
+                        values: [b]
                     } : null);
                 };
             }
@@ -76,13 +89,13 @@ c3_chart_internal_fn.getTooltipSortFunction = function() {
             return sortFunction;
 
         } else if (isArray(order)) {
-            return function(a, b) {
+            return function (a, b) {
                 return order.indexOf(a.id) - order.indexOf(b.id);
             };
         }
     } else {
         // if data are grouped, we follow the order of grouped targets
-        var ids = $$.orderTargets($$.data.targets).map(function(i) {
+        var ids = $$.orderTargets($$.data.targets).map(function (i) {
             return i.id;
         });
 
@@ -92,27 +105,32 @@ c3_chart_internal_fn.getTooltipSortFunction = function() {
             ids = ids.reverse();
         }
 
-        return function(a, b) {
+        return function (a, b) {
             return ids.indexOf(a.id) - ids.indexOf(b.id);
         };
     }
 };
-c3_chart_internal_fn.getTooltipContent = function (d, defaultTitleFormat, defaultValueFormat, color) {
-    var $$ = this, config = $$.config,
+ChartInternal.prototype.getTooltipContent = function (d, defaultTitleFormat, defaultValueFormat, color) {
+    var $$ = this,
+        config = $$.config,
         titleFormat = config.tooltip_format_title || defaultTitleFormat,
-        nameFormat = config.tooltip_format_name || function (name) { return name; },
+        nameFormat = config.tooltip_format_name || function (name) {
+            return name;
+        },
         valueFormat = config.tooltip_format_value || defaultValueFormat,
         text, i, title, value, name, bgcolor;
 
     var tooltipSortFunction = this.getTooltipSortFunction();
-    if(tooltipSortFunction) {
+    if (tooltipSortFunction) {
         d.sort(tooltipSortFunction);
     }
 
     for (i = 0; i < d.length; i++) {
-        if (! (d[i] && (d[i].value || d[i].value === 0))) { continue; }
+        if (!(d[i] && (d[i].value || d[i].value === 0))) {
+            continue;
+        }
 
-        if (! text) {
+        if (!text) {
             title = sanitise(titleFormat ? titleFormat(d[i].x) : d[i].x);
             text = "<table class='" + $$.CLASS.tooltip + "'>" + (title || title === 0 ? "<tr><th colspan='2'>" + title + "</th></tr>" : "");
         }
@@ -120,7 +138,9 @@ c3_chart_internal_fn.getTooltipContent = function (d, defaultTitleFormat, defaul
         value = sanitise(valueFormat(d[i].value, d[i].ratio, d[i].id, d[i].index, d));
         if (value !== undefined) {
             // Skip elements when their name is set to null
-            if (d[i].name === null) { continue; }
+            if (d[i].name === null) {
+                continue;
+            }
             name = sanitise(nameFormat(d[i].name, d[i].ratio, d[i].id, d[i].index));
             bgcolor = $$.levelColor ? $$.levelColor(d[i].value) : color(d[i].id);
 
@@ -132,12 +152,14 @@ c3_chart_internal_fn.getTooltipContent = function (d, defaultTitleFormat, defaul
     }
     return text + "</table>";
 };
-c3_chart_internal_fn.tooltipPosition = function (dataToShow, tWidth, tHeight, element) {
-    var $$ = this, config = $$.config, d3 = $$.d3;
+ChartInternal.prototype.tooltipPosition = function (dataToShow, tWidth, tHeight, element) {
+    var $$ = this,
+        config = $$.config,
+        d3 = $$.d3;
     var svgLeft, tooltipLeft, tooltipRight, tooltipTop, chartRight;
     var forArc = $$.hasArcType(),
         mouse = d3.mouse(element);
-  // Determin tooltip position
+    // Determin tooltip position
     if (forArc) {
         tooltipLeft = (($$.width - ($$.isLegendRight ? $$.getLegendWidth() : 0)) / 2) + mouse[0];
         tooltipTop = ($$.hasType('gauge') ? $$.height : $$.height / 2) + mouse[1] + 20;
@@ -166,14 +188,20 @@ c3_chart_internal_fn.tooltipPosition = function (dataToShow, tWidth, tHeight, el
     if (tooltipTop < 0) {
         tooltipTop = 0;
     }
-    return {top: tooltipTop, left: tooltipLeft};
+    return {
+        top: tooltipTop,
+        left: tooltipLeft
+    };
 };
-c3_chart_internal_fn.showTooltip = function (selectedData, element) {
-    var $$ = this, config = $$.config;
+ChartInternal.prototype.showTooltip = function (selectedData, element) {
+    var $$ = this,
+        config = $$.config;
     var tWidth, tHeight, position;
     var forArc = $$.hasArcType(),
-        dataToShow = selectedData.filter(function (d) { return d && isValue(d.value); }),
-        positionFunction = config.tooltip_position || c3_chart_internal_fn.tooltipPosition;
+        dataToShow = selectedData.filter(function (d) {
+            return d && isValue(d.value);
+        }),
+        positionFunction = config.tooltip_position || ChartInternal.prototype.tooltipPosition;
     if (dataToShow.length === 0 || !config.tooltip_show) {
         return;
     }
@@ -189,6 +217,6 @@ c3_chart_internal_fn.showTooltip = function (selectedData, element) {
         .style("top", position.top + "px")
         .style("left", position.left + 'px');
 };
-c3_chart_internal_fn.hideTooltip = function () {
+ChartInternal.prototype.hideTooltip = function () {
     this.tooltip.style("display", "none");
 };

src/type.js

@@ -1,7 +1,7 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 import { isString } from './util';
 
-c3_chart_internal_fn.setTargetType = function (targetIds, type) {
+ChartInternal.prototype.setTargetType = function (targetIds, type) {
     var $$ = this, config = $$.config;
     $$.mapToTargetIds(targetIds).forEach(function (id) {
         $$.withoutFadeIn[id] = (type === config.data_types[id]);
@@ -11,7 +11,7 @@ c3_chart_internal_fn.setTargetType = function (targetIds, type) {
         config.data_type = type;
     }
 };
-c3_chart_internal_fn.hasType = function (type, targets) {
+ChartInternal.prototype.hasType = function (type, targets) {
     var $$ = this, types = $$.config.data_types, has = false;
     targets = targets || $$.data.targets;
     if (targets && targets.length) {
@@ -30,52 +30,52 @@ c3_chart_internal_fn.hasType = function (type, targets) {
     }
     return has;
 };
-c3_chart_internal_fn.hasArcType = function (targets) {
+ChartInternal.prototype.hasArcType = function (targets) {
     return this.hasType('pie', targets) || this.hasType('donut', targets) || this.hasType('gauge', targets);
 };
-c3_chart_internal_fn.isLineType = function (d) {
+ChartInternal.prototype.isLineType = function (d) {
     var config = this.config, id = isString(d) ? d : d.id;
     return !config.data_types[id] || ['line', 'spline', 'area', 'area-spline', 'step', 'area-step'].indexOf(config.data_types[id]) >= 0;
 };
-c3_chart_internal_fn.isStepType = function (d) {
+ChartInternal.prototype.isStepType = function (d) {
     var id = isString(d) ? d : d.id;
     return ['step', 'area-step'].indexOf(this.config.data_types[id]) >= 0;
 };
-c3_chart_internal_fn.isSplineType = function (d) {
+ChartInternal.prototype.isSplineType = function (d) {
     var id = isString(d) ? d : d.id;
     return ['spline', 'area-spline'].indexOf(this.config.data_types[id]) >= 0;
 };
-c3_chart_internal_fn.isAreaType = function (d) {
+ChartInternal.prototype.isAreaType = function (d) {
     var id = isString(d) ? d : d.id;
     return ['area', 'area-spline', 'area-step'].indexOf(this.config.data_types[id]) >= 0;
 };
-c3_chart_internal_fn.isBarType = function (d) {
+ChartInternal.prototype.isBarType = function (d) {
     var id = isString(d) ? d : d.id;
     return this.config.data_types[id] === 'bar';
 };
-c3_chart_internal_fn.isScatterType = function (d) {
+ChartInternal.prototype.isScatterType = function (d) {
     var id = isString(d) ? d : d.id;
     return this.config.data_types[id] === 'scatter';
 };
-c3_chart_internal_fn.isPieType = function (d) {
+ChartInternal.prototype.isPieType = function (d) {
     var id = isString(d) ? d : d.id;
     return this.config.data_types[id] === 'pie';
 };
-c3_chart_internal_fn.isGaugeType = function (d) {
+ChartInternal.prototype.isGaugeType = function (d) {
     var id = isString(d) ? d : d.id;
     return this.config.data_types[id] === 'gauge';
 };
-c3_chart_internal_fn.isDonutType = function (d) {
+ChartInternal.prototype.isDonutType = function (d) {
     var id = isString(d) ? d : d.id;
     return this.config.data_types[id] === 'donut';
 };
-c3_chart_internal_fn.isArcType = function (d) {
+ChartInternal.prototype.isArcType = function (d) {
     return this.isPieType(d) || this.isDonutType(d) || this.isGaugeType(d);
 };
-c3_chart_internal_fn.lineData = function (d) {
+ChartInternal.prototype.lineData = function (d) {
     return this.isLineType(d) ? [d] : [];
 };
-c3_chart_internal_fn.arcData = function (d) {
+ChartInternal.prototype.arcData = function (d) {
     return this.isArcType(d.data) ? [d] : [];
 };
 /* not used
@@ -83,12 +83,12 @@ c3_chart_internal_fn.arcData = function (d) {
  return isScatterType(d) ? d.values : [];
  }
  */
-c3_chart_internal_fn.barData = function (d) {
+ChartInternal.prototype.barData = function (d) {
     return this.isBarType(d) ? d.values : [];
 };
-c3_chart_internal_fn.lineOrScatterData = function (d) {
+ChartInternal.prototype.lineOrScatterData = function (d) {
     return this.isLineType(d) || this.isScatterType(d) ? d.values : [];
 };
-c3_chart_internal_fn.barOrLineData = function (d) {
+ChartInternal.prototype.barOrLineData = function (d) {
     return this.isBarType(d) || this.isLineType(d) ? d.values : [];
 };

src/ua.js

@@ -1,10 +1,10 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.isSafari = function () {
+ChartInternal.prototype.isSafari = function () {
     var ua = window.navigator.userAgent;
     return ua.indexOf('Safari') >= 0 && ua.indexOf('Chrome') < 0;
 };
-c3_chart_internal_fn.isChrome = function () {
+ChartInternal.prototype.isChrome = function () {
     var ua = window.navigator.userAgent;
     return ua.indexOf('Chrome') >= 0;
 };

src/util.js

@@ -1,91 +1,53 @@
-import {ChartInternal} from './chart-internal';
-
-export var c3 = { version: "0.6.4" ,
-    chart: {
-        fn: Chart.prototype,
-        internal: {
-            fn: ChartInternal.prototype,
-        }
-    }
+export var asHalfPixel = function(n) {
+    return Math.ceil(n) + 0.5;
 };
-
-export function Chart(config) {
-    var $$ = this.internal = new ChartInternal(this);
-    $$.loadConfig(config);
-
-    $$.beforeInit(config);
-    $$.init();
-    $$.afterInit(config);
-
-    // bind "this" to nested API
-    (function bindThis(fn, target, argThis) {
-        Object.keys(fn).forEach(function (key) {
-            target[key] = fn[key].bind(argThis);
-            if (Object.keys(fn[key]).length > 0) {
-                bindThis(fn[key], target[key], argThis);
-            }
-        });
-    })(c3.chart.fn, this, this);
-}
-
-c3.generate = function (config) {
-    return new Chart(config);
+export var ceil10 = function(v) {
+    return Math.ceil(v / 10) * 10;
 };
-
-export function Component(owner, componentKey, fn) {
-    this.owner = owner;
-    c3.chart.internal[componentKey] = fn;
-}
-
-export var isValue = function (v) {
-    return v || v === 0;
+export var diffDomain = function(d) {
+    return d[1] - d[0];
 };
-export var isFunction = function (o) {
-    return typeof o === 'function';
+export var getOption = function(options, key, defaultValue) {
+    return isDefined(options[key]) ? options[key] : defaultValue;
 };
-export var isArray = function (o) {
-    return Array.isArray(o);
+export var getPathBox = function(path) {
+    var box = path.getBoundingClientRect(),
+        items = [path.pathSegList.getItem(0), path.pathSegList.getItem(1)],
+        minX = items[0].x,
+        minY = Math.min(items[0].y, items[1].y);
+    return { x: minX, y: minY, width: box.width, height: box.height };
 };
-export var isString = function (o) {
-    return typeof o === 'string';
+export var hasValue = function(dict, value) {
+    var found = false;
+    Object.keys(dict).forEach(function(key) {
+        if (dict[key] === value) { found = true; }
+    });
+    return found;
 };
-export var isUndefined = function (v) {
-    return typeof v === 'undefined';
+export var isArray = function(o) {
+    return Array.isArray(o);
 };
-export var isDefined = function (v) {
+export var isDefined = function(v) {
     return typeof v !== 'undefined';
 };
-export var ceil10 = function (v) {
-    return Math.ceil(v / 10) * 10;
-};
-export var asHalfPixel = function (n) {
-    return Math.ceil(n) + 0.5;
+export var isEmpty = function(o) {
+    return typeof o === 'undefined' || o === null || (isString(o) && o.length === 0) || (typeof o === 'object' && Object.keys(o).length === 0);
 };
-export var diffDomain = function (d) {
-    return d[1] - d[0];
+export var isFunction = function(o) {
+    return typeof o === 'function';
 };
-export var isEmpty = function (o) {
-    return typeof o === 'undefined' || o === null || (isString(o) && o.length === 0) || (typeof o === 'object' && Object.keys(o).length === 0);
+export var isString = function(o) {
+    return typeof o === 'string';
 };
-export var notEmpty = function (o) {
-    return !c3.chart.internal.fn.isEmpty(o);
+export var isUndefined = function(v) {
+    return typeof v === 'undefined';
 };
-export var getOption = function (options, key, defaultValue) {
-    return isDefined(options[key]) ? options[key] : defaultValue;
+export var isValue = function(v) {
+    return v || v === 0;
 };
-export var hasValue = function (dict, value) {
-    var found = false;
-    Object.keys(dict).forEach(function (key) {
-        if (dict[key] === value) { found = true; }
-    });
-    return found;
+export var notEmpty = function(o) {
+    return !isEmpty(o);
 };
-export var sanitise = function (str) {
+export var sanitise = function(str) {
     return typeof str === 'string' ? str.replace(/</g, '&lt;').replace(/>/g, '&gt;') : str;
 };
-export var getPathBox = function (path) {
-    var box = path.getBoundingClientRect(),
-        items = [path.pathSegList.getItem(0), path.pathSegList.getItem(1)],
-        minX = items[0].x, minY = Math.min(items[0].y, items[1].y);
-    return {x: minX, y: minY, width: box.width, height: box.height};
-};

src/zoom.js

@@ -1,6 +1,6 @@
-import { c3_chart_internal_fn } from './core';
+import { ChartInternal } from './core';
 
-c3_chart_internal_fn.initZoom = function () {
+ChartInternal.prototype.initZoom = function () {
     var $$ = this, d3 = $$.d3, config = $$.config, startEvent;
 
     $$.zoom = d3.zoom()
@@ -43,18 +43,18 @@ c3_chart_internal_fn.initZoom = function () {
 
     return $$.zoom.updateExtent();
 };
-c3_chart_internal_fn.zoomTransform = function (range) {
+ChartInternal.prototype.zoomTransform = function (range) {
     var $$ = this, s = [$$.x(range[0]), $$.x(range[1])];
     return $$.d3.zoomIdentity.scale($$.width / (s[1] - s[0])).translate(-s[0], 0);
 };
 
-c3_chart_internal_fn.getZoomDomain = function () {
+ChartInternal.prototype.getZoomDomain = function () {
     var $$ = this, config = $$.config, d3 = $$.d3,
         min = d3.min([$$.orgXDomain[0], config.zoom_x_min]),
         max = d3.max([$$.orgXDomain[1], config.zoom_x_max]);
     return [min, max];
 };
-c3_chart_internal_fn.redrawForZoom = function () {
+ChartInternal.prototype.redrawForZoom = function () {
     var $$ = this, d3 = $$.d3, config = $$.config, zoom = $$.zoom, x = $$.x;
     if (!config.zoom_enabled) {
         return;