Support date for zoom API

c3.js

@@ -5535,8 +5535,14 @@
 
     c3_chart_fn.zoom = function (domain) {
         var $$ = this.internal;
+        if (domain) {
+            if ($$.isTimeSeries()) {
+                domain = domain.map(function (x) { return $$.parseDate(x); });
+            }
             $$.brush.extent(domain);
             $$.redraw({withUpdateXDomain: true});
+        }
+        return $$.brush.extent();
     };
     c3_chart_fn.zoom.enable = function (enabled) {
         var $$ = this.internal;

spec/api.zoom-spec.js

@@ -37,35 +37,88 @@ describe('c3 api zoom', function () {
     describe('zoom', function () {
 
         it('should be zoomed properly', function () {
-            chart.zoom([3, 5]);
+            var target = [3, 5], domain;
-            var domain = chart.internal.x.domain();
+            chart.zoom(target);
-            expect(domain[0]).toBe(3);
+            domain = chart.internal.x.domain();
-            expect(domain[1]).toBe(5);
+            expect(domain[0]).toBe(target[0]);
+            expect(domain[1]).toBe(target[1]);
         });
 
         it('should be zoomed properly again', function () {
-            chart.zoom([1, 4]);
+            var target = [1, 4], domain;
-            var domain = chart.internal.x.domain();
+            chart.zoom(target);
-            expect(domain[0]).toBe(1);
+            domain = chart.internal.x.domain();
-            expect(domain[1]).toBe(4);
+            expect(domain[0]).toBe(target[0]);
+            expect(domain[1]).toBe(target[1]);
+        });
+
+        it('should load timeseries data', function () {
+            args = {
+                data: {
+                    x: 'date',
+                    columns: [
+                        ['date', '2014-01-01', '2014-01-02', '2014-08-01', '2014-10-19'],
+                        ['data1', 30, 200, 100, 400]
+                    ]
+                },
+                axis: {
+                    x: {
+                        type: 'timeseries'
+                    }
+                },
+                zoom: {
+                    enabled: true
+                }
+            };
+            expect(true).toBeTruthy();
+        });
+
+        it('should be zoomed properly', function () {
+            var target = [new Date(2014, 7, 1), new Date(2014, 8, 1)], domain;
+            chart.zoom(target);
+            domain = chart.internal.x.domain();
+            expect(+domain[0]).toBe(+target[0]);
+            expect(+domain[1]).toBe(+target[1]);
+        });
+
+        it('should be zoomed properly', function () {
+            var target = ['2014-08-01', '2014-09-01'], domain;
+            chart.zoom(target);
+            domain = chart.internal.x.domain();
+            expect(+domain[0]).toBe(+chart.internal.parseDate(target[0]));
+            expect(+domain[1]).toBe(+chart.internal.parseDate(target[1]));
         });
 
     });
 
     describe('unzoom', function () {
 
+        it('should load indexed data', function () {
+            args = {
+                data: {
+                    columns: [
+                        ['data1', 30, 200, 100, 400, 150, 250]
+                    ]
+                },
+                zoom: {
+                    enabled: true
+                }
+            };
+            expect(true).toBeTruthy();
+        });
+
         it('should be unzoomed properly', function () {
-            var domain;
+            var target = [1, 4], orginal = chart.internal.x.domain(), domain;
 
-            chart.zoom([1, 4]);
+            chart.zoom(target);
             domain = chart.internal.x.domain();
-            expect(domain[0]).toBe(1);
+            expect(domain[0]).toBe(target[0]);
-            expect(domain[1]).toBe(4);
+            expect(domain[1]).toBe(target[1]);
 
             chart.unzoom();
             domain = chart.internal.x.domain();
-            expect(domain[0]).toBe(-0.05);
+            expect(domain[0]).toBe(orginal[0]);
-            expect(domain[1]).toBe(5.05);
+            expect(domain[1]).toBe(orginal[1]);
         });
 
     });

src/api.zoom.js

@@ -1,7 +1,13 @@
 c3_chart_fn.zoom = function (domain) {
     var $$ = this.internal;
+    if (domain) {
+        if ($$.isTimeSeries()) {
+            domain = domain.map(function (x) { return $$.parseDate(x); });
+        }
         $$.brush.extent(domain);
         $$.redraw({withUpdateXDomain: true});
+    }
+    return $$.brush.extent();
 };
 c3_chart_fn.zoom.enable = function (enabled) {
     var $$ = this.internal;