c3/es6_modules/chart/api.flow.js

import {
    CLASS,
    isValue,
    isFunction,
    isString,
    isUndefined,
    isDefined,
    ceil10,
    asHalfPixel,
    diffDomain,
    isEmpty,
    notEmpty,
    getOption,
    hasValue,
    sanitise,
    getPathBox,
    ChartInternal
} from '../chartinternal.js';

const flow = function (args) {
    let $$ = this.internal,
        targets, data, notfoundIds = [],
        orgDataCount = $$.getMaxDataCount(),
        dataCount, domain, baseTarget, baseValue, length = 0,
        tail = 0,
        diff, to;

    if (args.json) {
        data = $$.convertJsonToData(args.json, args.keys);
    } else if (args.rows) {
        data = $$.convertRowsToData(args.rows);
    } else if (args.columns) {
        data = $$.convertColumnsToData(args.columns);
    } else {
        return;
    }
    targets = $$.convertDataToTargets(data, true);

    // Update/Add data
    $$.data.targets.forEach((t) => {
        let found = false,
            i, j;
        for (i = 0; i < targets.length; i++) {
            if (t.id === targets[i].id) {
                found = true;

                if (t.values[t.values.length - 1]) {
                    tail = t.values[t.values.length - 1].index + 1;
                }
                length = targets[i].values.length;

                for (j = 0; j < length; j++) {
                    targets[i].values[j].index = tail + j;
                    if (!$$.isTimeSeries()) {
                        targets[i].values[j].x = tail + j;
                    }
                }
                t.values = t.values.concat(targets[i].values);

                targets.splice(i, 1);
                break;
            }
        }
        if (!found) { notfoundIds.push(t.id); }
    });

    // Append null for not found targets
    $$.data.targets.forEach((t) => {
        let i, j;
        for (i = 0; i < notfoundIds.length; i++) {
            if (t.id === notfoundIds[i]) {
                tail = t.values[t.values.length - 1].index + 1;
                for (j = 0; j < length; j++) {
                    t.values.push({
                        id: t.id,
                        index: tail + j,
                        x: $$.isTimeSeries() ? $$.getOtherTargetX(tail + j) : tail + j,
                        value: null,
                    });
                }
            }
        }
    });

    // Generate null values for new target
    if ($$.data.targets.length) {
        targets.forEach((t) => {
            let i, missing = [];
            for (i = $$.data.targets[0].values[0].index; i < tail; i++) {
                missing.push({
                    id: t.id,
                    index: i,
                    x: $$.isTimeSeries() ? $$.getOtherTargetX(i) : i,
                    value: null,
                });
            }
            t.values.forEach((v) => {
                v.index += tail;
                if (!$$.isTimeSeries()) {
                    v.x += tail;
                }
            });
            t.values = missing.concat(t.values);
        });
    }
    $$.data.targets = $$.data.targets.concat(targets); // add remained

    // check data count because behavior needs to change when it's only one
    dataCount = $$.getMaxDataCount();
    baseTarget = $$.data.targets[0];
    baseValue = baseTarget.values[0];

    // Update length to flow if needed
    if (isDefined(args.to)) {
        length = 0;
        to = $$.isTimeSeries() ? $$.parseDate(args.to) : args.to;
        baseTarget.values.forEach((v) => {
            if (v.x < to) { length++; }
        });
    } else if (isDefined(args.length)) {
        length = args.length;
    }

    // If only one data, update the domain to flow from left edge of the chart
    if (!orgDataCount) {
        if ($$.isTimeSeries()) {
            if (baseTarget.values.length > 1) {
                diff = baseTarget.values[baseTarget.values.length - 1].x - baseValue.x;
            } else {
                diff = baseValue.x - $$.getXDomain($$.data.targets)[0];
            }
        } else {
            diff = 1;
        }
        domain = [baseValue.x - diff, baseValue.x];
        $$.updateXDomain(null, true, true, false, domain);
    } else if (orgDataCount === 1) {
        if ($$.isTimeSeries()) {
            diff = (baseTarget.values[baseTarget.values.length - 1].x - baseValue.x) / 2;
            domain = [new Date(+baseValue.x - diff), new Date(+baseValue.x + diff)];
            $$.updateXDomain(null, true, true, false, domain);
        }
    }

    // Set targets
    $$.updateTargets($$.data.targets);

    // Redraw with new targets
    $$.redraw({
        flow: {
            index: baseValue.index,
            length,
            duration: isValue(args.duration) ? args.duration : $$.config.transition_duration,
            done: args.done,
            orgDataCount,
        },
        withLegend: true,
        withTransition: orgDataCount > 1,
        withTrimXDomain: false,
        withUpdateXAxis: true,
    });
};

export { flow };