Source: base-mixin.js

/**
 * `dc.baseMixin` is an abstract functional object representing a basic `dc` chart object
 * for all chart and widget implementations. Methods from the {@link #dc.baseMixin dc.baseMixin} are inherited
 * and available on all chart implementations in the `dc` library.
 * @name baseMixin
 * @memberof dc
 * @mixin
 * @param {Object} _chart
 * @returns {dc.baseMixin}
 */
dc.baseMixin = function (_chart) {
    _chart.__dcFlag__ = dc.utils.uniqueId();

    var _dimension;
    var _group;

    var _anchor;
    var _root;
    var _svg;
    var _isChild;

    var _minWidth = 200;
    var _defaultWidthCalc = function (element) {
        var width = element && element.getBoundingClientRect && element.getBoundingClientRect().width;
        return (width && width > _minWidth) ? width : _minWidth;
    };
    var _widthCalc = _defaultWidthCalc;

    var _minHeight = 200;
    var _defaultHeightCalc = function (element) {
        var height = element && element.getBoundingClientRect && element.getBoundingClientRect().height;
        return (height && height > _minHeight) ? height : _minHeight;
    };
    var _heightCalc = _defaultHeightCalc;
    var _width, _height;
    var _useViewBoxResizing = false;

    var _keyAccessor = dc.pluck('key');
    var _valueAccessor = dc.pluck('value');
    var _label = dc.pluck('key');

    var _ordering = dc.pluck('key');

    var _renderLabel = false;

    var _title = function (d) {
        return _chart.keyAccessor()(d) + ': ' + _chart.valueAccessor()(d);
    };
    var _renderTitle = true;
    var _controlsUseVisibility = false;

    var _transitionDuration = 750;

    var _transitionDelay = 0;

    var _filterPrinter = dc.printers.filters;

    var _mandatoryAttributes = ['dimension', 'group'];

    var _chartGroup = dc.constants.DEFAULT_CHART_GROUP;

    var _listeners = d3.dispatch(
        'preRender',
        'postRender',
        'preRedraw',
        'postRedraw',
        'filtered',
        'zoomed',
        'renderlet',
        'pretransition');

    var _legend;
    var _commitHandler;

    var _filters = [];
    var _filterHandler = function (dimension, filters) {
        if (filters.length === 0) {
            dimension.filter(null);
        } else if (filters.length === 1 && !filters[0].isFiltered) {
            // single value and not a function-based filter
            dimension.filterExact(filters[0]);
        } else if (filters.length === 1 && filters[0].filterType === 'RangedFilter') {
            // single range-based filter
            dimension.filterRange(filters[0]);
        } else {
            dimension.filterFunction(function (d) {
                for (var i = 0; i < filters.length; i++) {
                    var filter = filters[i];
                    if (filter.isFiltered && filter.isFiltered(d)) {
                        return true;
                    } else if (filter <= d && filter >= d) {
                        return true;
                    }
                }
                return false;
            });
        }
        return filters;
    };

    var _data = function (group) {
        return group.all();
    };

    /**
     * Set or get the height attribute of a chart. The height is applied to the SVGElement generated by
     * the chart when rendered (or re-rendered). If a value is given, then it will be used to calculate
     * the new height and the chart returned for method chaining.  The value can either be a numeric, a
     * function, or falsy. If no value is specified then the value of the current height attribute will
     * be returned.
     *
     * By default, without an explicit height being given, the chart will select the width of its
     * anchor element. If that isn't possible it defaults to 200 (provided by the
     * {@link dc.baseMixin#minHeight minHeight} property). Setting the value falsy will return
     * the chart to the default behavior.
     * @method height
     * @memberof dc.baseMixin
     * @instance
     * @see {@link dc.baseMixin#minHeight minHeight}
     * @example
     * // Default height
     * chart.height(function (element) {
     *     var height = element && element.getBoundingClientRect && element.getBoundingClientRect().height;
     *     return (height && height > chart.minHeight()) ? height : chart.minHeight();
     * });
     *
     * chart.height(250); // Set the chart's height to 250px;
     * chart.height(function(anchor) { return doSomethingWith(anchor); }); // set the chart's height with a function
     * chart.height(null); // reset the height to the default auto calculation
     * @param {Number|Function} [height]
     * @returns {Number|dc.baseMixin}
     */
    _chart.height = function (height) {
        if (!arguments.length) {
            if (!dc.utils.isNumber(_height)) {
                // only calculate once
                _height = _heightCalc(_root.node());
            }
            return _height;
        }
        _heightCalc = height ? (typeof height === 'function' ? height : dc.utils.constant(height)) : _defaultHeightCalc;
        _height = undefined;
        return _chart;
    };

    /**
     * Set or get the width attribute of a chart.
     * @method width
     * @memberof dc.baseMixin
     * @instance
     * @see {@link dc.baseMixin#height height}
     * @see {@link dc.baseMixin#minWidth minWidth}
     * @example
     * // Default width
     * chart.width(function (element) {
     *     var width = element && element.getBoundingClientRect && element.getBoundingClientRect().width;
     *     return (width && width > chart.minWidth()) ? width : chart.minWidth();
     * });
     * @param {Number|Function} [width]
     * @returns {Number|dc.baseMixin}
     */
    _chart.width = function (width) {
        if (!arguments.length) {
            if (!dc.utils.isNumber(_width)) {
                // only calculate once
                _width = _widthCalc(_root.node());
            }
            return _width;
        }
        _widthCalc = width ? (typeof width === 'function' ? width : dc.utils.constant(width)) : _defaultWidthCalc;
        _width = undefined;
        return _chart;
    };

    /**
     * Set or get the minimum width attribute of a chart. This only has effect when used with the default
     * {@link dc.baseMixin#width width} function.
     * @method minWidth
     * @memberof dc.baseMixin
     * @instance
     * @see {@link dc.baseMixin#width width}
     * @param {Number} [minWidth=200]
     * @returns {Number|dc.baseMixin}
     */
    _chart.minWidth = function (minWidth) {
        if (!arguments.length) {
            return _minWidth;
        }
        _minWidth = minWidth;
        return _chart;
    };

    /**
     * Set or get the minimum height attribute of a chart. This only has effect when used with the default
     * {@link dc.baseMixin#height height} function.
     * @method minHeight
     * @memberof dc.baseMixin
     * @instance
     * @see {@link dc.baseMixin#height height}
     * @param {Number} [minHeight=200]
     * @returns {Number|dc.baseMixin}
     */
    _chart.minHeight = function (minHeight) {
        if (!arguments.length) {
            return _minHeight;
        }
        _minHeight = minHeight;
        return _chart;
    };

    /**
     * Turn on/off using the SVG
     * {@link https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/viewBox `viewBox` attribute}.
     * When enabled, `viewBox` will be set on the svg root element instead of `width` and `height`.
     * Requires that the chart aspect ratio be defined using chart.width(w) and chart.height(h).
     *
     * This will maintain the aspect ratio while enabling the chart to resize responsively to the
     * space given to the chart using CSS. For example, the chart can use `width: 100%; height:
     * 100%` or absolute positioning to resize to its parent div.
     *
     * Since the text will be sized as if the chart is drawn according to the width and height, and
     * will be resized if the chart is any other size, you need to set the chart width and height so
     * that the text looks good. In practice, 600x400 seems to work pretty well for most charts.
     *
     * You can see examples of this resizing strategy in the [Chart Resizing
     * Examples](http://dc-js.github.io/dc.js/resizing/); just add `?resize=viewbox` to any of the
     * one-chart examples to enable `useViewBoxResizing`.
     * @method useViewBoxResizing
     * @memberof dc.baseMixin
     * @instance
     * @param {Boolean} [useViewBoxResizing=false]
     * @returns {Boolean|dc.baseMixin}
     */
    _chart.useViewBoxResizing = function (useViewBoxResizing) {
        if (!arguments.length) {
            return _useViewBoxResizing;
        }
        _useViewBoxResizing = useViewBoxResizing;
        return _chart;
    };

    /**
     * **mandatory**
     *
     * Set or get the dimension attribute of a chart. In `dc`, a dimension can be any valid
     * {@link https://github.com/crossfilter/crossfilter/wiki/API-Reference#dimension crossfilter dimension}
     *
     * If a value is given, then it will be used as the new dimension. If no value is specified then
     * the current dimension will be returned.
     * @method dimension
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://github.com/crossfilter/crossfilter/wiki/API-Reference#dimension crossfilter.dimension}
     * @example
     * var index = crossfilter([]);
     * var dimension = index.dimension(dc.pluck('key'));
     * chart.dimension(dimension);
     * @param {crossfilter.dimension} [dimension]
     * @returns {crossfilter.dimension|dc.baseMixin}
     */
    _chart.dimension = function (dimension) {
        if (!arguments.length) {
            return _dimension;
        }
        _dimension = dimension;
        _chart.expireCache();
        return _chart;
    };

    /**
     * Set the data callback or retrieve the chart's data set. The data callback is passed the chart's
     * group and by default will return
     * {@link https://github.com/crossfilter/crossfilter/wiki/API-Reference#group_all group.all}.
     * This behavior may be modified to, for instance, return only the top 5 groups.
     * @method data
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // Default data function
     * chart.data(function (group) { return group.all(); });
     *
     * chart.data(function (group) { return group.top(5); });
     * @param {Function} [callback]
     * @returns {*|dc.baseMixin}
     */
    _chart.data = function (callback) {
        if (!arguments.length) {
            return _data.call(_chart, _group);
        }
        _data = typeof callback === 'function' ? callback : dc.utils.constant(callback);
        _chart.expireCache();
        return _chart;
    };

    /**
     * **mandatory**
     *
     * Set or get the group attribute of a chart. In `dc` a group is a
     * {@link https://github.com/crossfilter/crossfilter/wiki/API-Reference#group-map-reduce crossfilter group}.
     * Usually the group should be created from the particular dimension associated with the same chart. If a value is
     * given, then it will be used as the new group.
     *
     * If no value specified then the current group will be returned.
     * If `name` is specified then it will be used to generate legend label.
     * @method group
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://github.com/crossfilter/crossfilter/wiki/API-Reference#group-map-reduce crossfilter.group}
     * @example
     * var index = crossfilter([]);
     * var dimension = index.dimension(dc.pluck('key'));
     * chart.dimension(dimension);
     * chart.group(dimension.group().reduceSum());
     * @param {crossfilter.group} [group]
     * @param {String} [name]
     * @returns {crossfilter.group|dc.baseMixin}
     */
    _chart.group = function (group, name) {
        if (!arguments.length) {
            return _group;
        }
        _group = group;
        _chart._groupName = name;
        _chart.expireCache();
        return _chart;
    };

    /**
     * Get or set an accessor to order ordinal dimensions.  The chart uses
     * {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort Array.sort}
     * to sort elements; this accessor returns the value to order on.
     * @method ordering
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // Default ordering accessor
     * _chart.ordering(dc.pluck('key'));
     * @param {Function} [orderFunction]
     * @returns {Function|dc.baseMixin}
     */
    _chart.ordering = function (orderFunction) {
        if (!arguments.length) {
            return _ordering;
        }
        _ordering = orderFunction;
        _chart.expireCache();
        return _chart;
    };

    _chart._computeOrderedGroups = function (data) {
        // clone the array before sorting, otherwise Array.sort sorts in-place
        return data.slice().sort(function (a, b) { return _ordering(a) - _ordering(b) });
    };

    /**
     * Clear all filters associated with this chart. The same effect can be achieved by calling
     * {@link dc.baseMixin#filter chart.filter(null)}.
     * @method filterAll
     * @memberof dc.baseMixin
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.filterAll = function () {
        return _chart.filter(null);
    };

    /**
     * Execute d3 single selection in the chart's scope using the given selector and return the d3
     * selection.
     *
     * This function is **not chainable** since it does not return a chart instance; however the d3
     * selection result can be chained to d3 function calls.
     * @method select
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://github.com/d3/d3-selection/blob/master/README.md#select d3.select}
     * @example
     * // Has the same effect as d3.select('#chart-id').select(selector)
     * chart.select(selector)
     * @param {String} sel CSS selector string
     * @returns {d3.selection}
     */
    _chart.select = function (sel) {
        return _root.select(sel);
    };

    /**
     * Execute in scope d3 selectAll using the given selector and return d3 selection result.
     *
     * This function is **not chainable** since it does not return a chart instance; however the d3
     * selection result can be chained to d3 function calls.
     * @method selectAll
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://github.com/d3/d3-selection/blob/master/README.md#selectAll d3.selectAll}
     * @example
     * // Has the same effect as d3.select('#chart-id').selectAll(selector)
     * chart.selectAll(selector)
     * @param {String} sel CSS selector string
     * @returns {d3.selection}
     */
    _chart.selectAll = function (sel) {
        return _root ? _root.selectAll(sel) : null;
    };

    /**
     * Set the root SVGElement to either be an existing chart's root; or any valid [d3 single
     * selector](https://github.com/d3/d3-selection/blob/master/README.md#selecting-elements) specifying a dom
     * block element such as a div; or a dom element or d3 selection. Optionally registers the chart
     * within the chartGroup. This class is called internally on chart initialization, but be called
     * again to relocate the chart. However, it will orphan any previously created SVGElements.
     * @method anchor
     * @memberof dc.baseMixin
     * @instance
     * @param {anchorChart|anchorSelector|anchorNode} [parent]
     * @param {String} [chartGroup]
     * @returns {String|node|d3.selection|dc.baseMixin}
     */
    _chart.anchor = function (parent, chartGroup) {
        if (!arguments.length) {
            return _anchor;
        }
        if (dc.instanceOfChart(parent)) {
            _anchor = parent.anchor();
            if (_anchor.children) { // is _anchor a div?
                _anchor = '#' + parent.anchorName();
            }
            _root = parent.root();
            _isChild = true;
        } else if (parent) {
            if (parent.select && parent.classed) { // detect d3 selection
                _anchor = parent.node();
            } else {
                _anchor = parent;
            }
            _root = d3.select(_anchor);
            _root.classed(dc.constants.CHART_CLASS, true);
            dc.registerChart(_chart, chartGroup);
            _isChild = false;
        } else {
            throw new dc.errors.BadArgumentException('parent must be defined');
        }
        _chartGroup = chartGroup;
        return _chart;
    };

    /**
     * Returns the DOM id for the chart's anchored location.
     * @method anchorName
     * @memberof dc.baseMixin
     * @instance
     * @returns {String}
     */
    _chart.anchorName = function () {
        var a = _chart.anchor();
        if (a && a.id) {
            return a.id;
        }
        if (a && a.replace) {
            return a.replace('#', '');
        }
        return 'dc-chart' + _chart.chartID();
    };

    /**
     * Returns the root element where a chart resides. Usually it will be the parent div element where
     * the SVGElement was created. You can also pass in a new root element however this is usually handled by
     * dc internally. Resetting the root element on a chart outside of dc internals may have
     * unexpected consequences.
     * @method root
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement HTMLElement}
     * @param {HTMLElement} [rootElement]
     * @returns {HTMLElement|dc.baseMixin}
     */
    _chart.root = function (rootElement) {
        if (!arguments.length) {
            return _root;
        }
        _root = rootElement;
        return _chart;
    };

    /**
     * Returns the top SVGElement for this specific chart. You can also pass in a new SVGElement,
     * however this is usually handled by dc internally. Resetting the SVGElement on a chart outside
     * of dc internals may have unexpected consequences.
     * @method svg
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/SVGElement SVGElement}
     * @param {SVGElement|d3.selection} [svgElement]
     * @returns {SVGElement|d3.selection|dc.baseMixin}
     */
    _chart.svg = function (svgElement) {
        if (!arguments.length) {
            return _svg;
        }
        _svg = svgElement;
        return _chart;
    };

    /**
     * Remove the chart's SVGElements from the dom and recreate the container SVGElement.
     * @method resetSvg
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://developer.mozilla.org/en-US/docs/Web/API/SVGElement SVGElement}
     * @returns {SVGElement}
     */
    _chart.resetSvg = function () {
        _chart.select('svg').remove();
        return generateSvg();
    };

    function sizeSvg () {
        if (_svg) {
            if (!_useViewBoxResizing) {
                _svg
                    .attr('width', _chart.width())
                    .attr('height', _chart.height());
            } else if (!_svg.attr('viewBox')) {
                _svg
                    .attr('viewBox', '0 0 ' + _chart.width() + ' ' + _chart.height());
            }
        }
    }

    function generateSvg () {
        _svg = _chart.root().append('svg');
        sizeSvg();
        return _svg;
    }

    /**
     * Set or get the filter printer function. The filter printer function is used to generate human
     * friendly text for filter value(s) associated with the chart instance. The text will get shown
     * in the `.filter element; see {@link dc.baseMixin#turnOnControls turnOnControls}.
     *
     * By default dc charts use a default filter printer {@link dc.printers.filters dc.printers.filters}
     * that provides simple printing support for both single value and ranged filters.
     * @method filterPrinter
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // for a chart with an ordinal brush, print the filters in upper case
     * chart.filterPrinter(function(filters) {
     *   return filters.map(function(f) { return f.toUpperCase(); }).join(', ');
     * });
     * // for a chart with a range brush, print the filter as start and extent
     * chart.filterPrinter(function(filters) {
     *   return 'start ' + dc.utils.printSingleValue(filters[0][0]) +
     *     ' extent ' + dc.utils.printSingleValue(filters[0][1] - filters[0][0]);
     * });
     * @param {Function} [filterPrinterFunction=dc.printers.filters]
     * @returns {Function|dc.baseMixin}
     */
    _chart.filterPrinter = function (filterPrinterFunction) {
        if (!arguments.length) {
            return _filterPrinter;
        }
        _filterPrinter = filterPrinterFunction;
        return _chart;
    };

    /**
     * If set, use the `visibility` attribute instead of the `display` attribute for showing/hiding
     * chart reset and filter controls, for less disruption to the layout.
     * @method controlsUseVisibility
     * @memberof dc.baseMixin
     * @instance
     * @param {Boolean} [controlsUseVisibility=false]
     * @returns {Boolean|dc.baseMixin}
     **/
    _chart.controlsUseVisibility = function (controlsUseVisibility) {
        if (!arguments.length) {
            return _controlsUseVisibility;
        }
        _controlsUseVisibility = controlsUseVisibility;
        return _chart;
    };

    /**
     * Turn on optional control elements within the root element. dc currently supports the
     * following html control elements.
     * * root.selectAll('.reset') - elements are turned on if the chart has an active filter. This type
     * of control element is usually used to store a reset link to allow user to reset filter on a
     * certain chart. This element will be turned off automatically if the filter is cleared.
     * * root.selectAll('.filter') elements are turned on if the chart has an active filter. The text
     * content of this element is then replaced with the current filter value using the filter printer
     * function. This type of element will be turned off automatically if the filter is cleared.
     * @method turnOnControls
     * @memberof dc.baseMixin
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.turnOnControls = function () {
        if (_root) {
            var attribute = _chart.controlsUseVisibility() ? 'visibility' : 'display';
            _chart.selectAll('.reset').style(attribute, null);
            _chart.selectAll('.filter').text(_filterPrinter(_chart.filters())).style(attribute, null);
        }
        return _chart;
    };

    /**
     * Turn off optional control elements within the root element.
     * @method turnOffControls
     * @memberof dc.baseMixin
     * @see {@link dc.baseMixin#turnOnControls turnOnControls}
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.turnOffControls = function () {
        if (_root) {
            var attribute = _chart.controlsUseVisibility() ? 'visibility' : 'display';
            var value = _chart.controlsUseVisibility() ? 'hidden' : 'none';
            _chart.selectAll('.reset').style(attribute, value);
            _chart.selectAll('.filter').style(attribute, value).text(_chart.filter());
        }
        return _chart;
    };

    /**
     * Set or get the animation transition duration (in milliseconds) for this chart instance.
     * @method transitionDuration
     * @memberof dc.baseMixin
     * @instance
     * @param {Number} [duration=750]
     * @returns {Number|dc.baseMixin}
     */
    _chart.transitionDuration = function (duration) {
        if (!arguments.length) {
            return _transitionDuration;
        }
        _transitionDuration = duration;
        return _chart;
    };

    /**
     * Set or get the animation transition delay (in milliseconds) for this chart instance.
     * @method transitionDelay
     * @memberof dc.baseMixin
     * @instance
     * @param {Number} [delay=0]
     * @returns {Number|dc.baseMixin}
     */
    _chart.transitionDelay = function (delay) {
        if (!arguments.length) {
            return _transitionDelay;
        }
        _transitionDelay = delay;
        return _chart;
    };

    _chart._mandatoryAttributes = function (_) {
        if (!arguments.length) {
            return _mandatoryAttributes;
        }
        _mandatoryAttributes = _;
        return _chart;
    };

    function checkForMandatoryAttributes (a) {
        if (!_chart[a] || !_chart[a]()) {
            throw new dc.errors.InvalidStateException('Mandatory attribute chart.' + a +
                ' is missing on chart[#' + _chart.anchorName() + ']');
        }
    }

    /**
     * Invoking this method will force the chart to re-render everything from scratch. Generally it
     * should only be used to render the chart for the first time on the page or if you want to make
     * sure everything is redrawn from scratch instead of relying on the default incremental redrawing
     * behaviour.
     * @method render
     * @memberof dc.baseMixin
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.render = function () {
        _height = _width = undefined; // force recalculate
        _listeners.call('preRender', _chart, _chart);

        if (_mandatoryAttributes) {
            _mandatoryAttributes.forEach(checkForMandatoryAttributes);
        }

        var result = _chart._doRender();

        if (_legend) {
            _legend.render();
        }

        _chart._activateRenderlets('postRender');

        return result;
    };

    _chart._activateRenderlets = function (event) {
        _listeners.call('pretransition', _chart, _chart);
        if (_chart.transitionDuration() > 0 && _svg) {
            _svg.transition().duration(_chart.transitionDuration()).delay(_chart.transitionDelay())
                .on('end', function () {
                    _listeners.call('renderlet', _chart, _chart);
                    if (event) {
                        _listeners.call(event, _chart, _chart);
                    }
                });
        } else {
            _listeners.call('renderlet', _chart, _chart);
            if (event) {
                _listeners.call(event, _chart, _chart);
            }
        }
    };

    /**
     * Calling redraw will cause the chart to re-render data changes incrementally. If there is no
     * change in the underlying data dimension then calling this method will have no effect on the
     * chart. Most chart interaction in dc will automatically trigger this method through internal
     * events (in particular {@link dc.redrawAll dc.redrawAll}); therefore, you only need to
     * manually invoke this function if data is manipulated outside of dc's control (for example if
     * data is loaded in the background using
     * {@link https://github.com/crossfilter/crossfilter/wiki/API-Reference#crossfilter_add crossfilter.add}).
     * @method redraw
     * @memberof dc.baseMixin
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.redraw = function () {
        sizeSvg();
        _listeners.call('preRedraw', _chart, _chart);

        var result = _chart._doRedraw();

        if (_legend) {
            _legend.render();
        }

        _chart._activateRenderlets('postRedraw');

        return result;
    };

    /**
     * Gets/sets the commit handler. If the chart has a commit handler, the handler will be called when
     * the chart's filters have changed, in order to send the filter data asynchronously to a server.
     *
     * Unlike other functions in dc.js, the commit handler is asynchronous. It takes two arguments:
     * a flag indicating whether this is a render (true) or a redraw (false), and a callback to be
     * triggered once the commit is done. The callback has the standard node.js continuation signature
     * with error first and result second.
     * @method commitHandler
     * @param {Function} commitHandler
     * @memberof dc.baseMixin
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.commitHandler = function (commitHandler) {
        if (!arguments.length) {
            return _commitHandler;
        }
        _commitHandler = commitHandler;
        return _chart;
    };

    /**
     * Redraws all charts in the same group as this chart, typically in reaction to a filter
     * change. If the chart has a {@link dc.baseMixin.commitFilter commitHandler}, it will
     * be executed and waited for.
     * @method redrawGroup
     * @memberof dc.baseMixin
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.redrawGroup = function () {
        if (_commitHandler) {
            _commitHandler(false, function (error, result) {
                if (error) {
                    console.log(error);
                } else {
                    dc.redrawAll(_chart.chartGroup());
                }
            });
        } else {
            dc.redrawAll(_chart.chartGroup());
        }
        return _chart;
    };

    /**
     * Renders all charts in the same group as this chart. If the chart has a
     * {@link dc.baseMixin.commitFilter commitHandler}, it will be executed and waited for
     * @method renderGroup
     * @memberof dc.baseMixin
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.renderGroup = function () {
        if (_commitHandler) {
            _commitHandler(false, function (error, result) {
                if (error) {
                    console.log(error);
                } else {
                    dc.renderAll(_chart.chartGroup());
                }
            });
        } else {
            dc.renderAll(_chart.chartGroup());
        }
        return _chart;
    };

    _chart._invokeFilteredListener = function (f) {
        if (f !== undefined) {
            _listeners.call('filtered', _chart, _chart, f);
        }
    };

    _chart._invokeZoomedListener = function () {
        _listeners.call('zoomed', _chart, _chart);
    };

    var _hasFilterHandler = function (filters, filter) {
        if (filter === null || typeof(filter) === 'undefined') {
            return filters.length > 0;
        }
        return filters.some(function (f) {
            return filter <= f && filter >= f;
        });
    };

    /**
     * Set or get the has-filter handler. The has-filter handler is a function that checks to see if
     * the chart's current filters (first argument) include a specific filter (second argument).  Using a custom has-filter handler allows
     * you to change the way filters are checked for and replaced.
     * @method hasFilterHandler
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // default has-filter handler
     * chart.hasFilterHandler(function (filters, filter) {
     *     if (filter === null || typeof(filter) === 'undefined') {
     *         return filters.length > 0;
     *     }
     *     return filters.some(function (f) {
     *         return filter <= f && filter >= f;
     *     });
     * });
     *
     * // custom filter handler (no-op)
     * chart.hasFilterHandler(function(filters, filter) {
     *     return false;
     * });
     * @param {Function} [hasFilterHandler]
     * @returns {Function|dc.baseMixin}
     */
    _chart.hasFilterHandler = function (hasFilterHandler) {
        if (!arguments.length) {
            return _hasFilterHandler;
        }
        _hasFilterHandler = hasFilterHandler;
        return _chart;
    };

    /**
     * Check whether any active filter or a specific filter is associated with particular chart instance.
     * This function is **not chainable**.
     * @method hasFilter
     * @memberof dc.baseMixin
     * @instance
     * @see {@link dc.baseMixin#hasFilterHandler hasFilterHandler}
     * @param {*} [filter]
     * @returns {Boolean}
     */
    _chart.hasFilter = function (filter) {
        return _hasFilterHandler(_filters, filter);
    };

    var _removeFilterHandler = function (filters, filter) {
        for (var i = 0; i < filters.length; i++) {
            if (filters[i] <= filter && filters[i] >= filter) {
                filters.splice(i, 1);
                break;
            }
        }
        return filters;
    };

    /**
     * Set or get the remove filter handler. The remove filter handler is a function that removes a
     * filter from the chart's current filters. Using a custom remove filter handler allows you to
     * change how filters are removed or perform additional work when removing a filter, e.g. when
     * using a filter server other than crossfilter.
     *
     * The handler should return a new or modified array as the result.
     * @method removeFilterHandler
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // default remove filter handler
     * chart.removeFilterHandler(function (filters, filter) {
     *     for (var i = 0; i < filters.length; i++) {
     *         if (filters[i] <= filter && filters[i] >= filter) {
     *             filters.splice(i, 1);
     *             break;
     *         }
     *     }
     *     return filters;
     * });
     *
     * // custom filter handler (no-op)
     * chart.removeFilterHandler(function(filters, filter) {
     *     return filters;
     * });
     * @param {Function} [removeFilterHandler]
     * @returns {Function|dc.baseMixin}
     */
    _chart.removeFilterHandler = function (removeFilterHandler) {
        if (!arguments.length) {
            return _removeFilterHandler;
        }
        _removeFilterHandler = removeFilterHandler;
        return _chart;
    };

    var _addFilterHandler = function (filters, filter) {
        filters.push(filter);
        return filters;
    };

    /**
     * Set or get the add filter handler. The add filter handler is a function that adds a filter to
     * the chart's filter list. Using a custom add filter handler allows you to change the way filters
     * are added or perform additional work when adding a filter, e.g. when using a filter server other
     * than crossfilter.
     *
     * The handler should return a new or modified array as the result.
     * @method addFilterHandler
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // default add filter handler
     * chart.addFilterHandler(function (filters, filter) {
     *     filters.push(filter);
     *     return filters;
     * });
     *
     * // custom filter handler (no-op)
     * chart.addFilterHandler(function(filters, filter) {
     *     return filters;
     * });
     * @param {Function} [addFilterHandler]
     * @returns {Function|dc.baseMixin}
     */
    _chart.addFilterHandler = function (addFilterHandler) {
        if (!arguments.length) {
            return _addFilterHandler;
        }
        _addFilterHandler = addFilterHandler;
        return _chart;
    };

    var _resetFilterHandler = function (filters) {
        return [];
    };

    /**
     * Set or get the reset filter handler. The reset filter handler is a function that resets the
     * chart's filter list by returning a new list. Using a custom reset filter handler allows you to
     * change the way filters are reset, or perform additional work when resetting the filters,
     * e.g. when using a filter server other than crossfilter.
     *
     * The handler should return a new or modified array as the result.
     * @method resetFilterHandler
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // default remove filter handler
     * function (filters) {
     *     return [];
     * }
     *
     * // custom filter handler (no-op)
     * chart.resetFilterHandler(function(filters) {
     *     return filters;
     * });
     * @param {Function} [resetFilterHandler]
     * @returns {dc.baseMixin}
     */
    _chart.resetFilterHandler = function (resetFilterHandler) {
        if (!arguments.length) {
            return _resetFilterHandler;
        }
        _resetFilterHandler = resetFilterHandler;
        return _chart;
    };

    function applyFilters (filters) {
        if (_chart.dimension() && _chart.dimension().filter) {
            var fs = _filterHandler(_chart.dimension(), filters);
            if (fs) {
                filters = fs;
            }
        }
        return filters;
    }

    /**
     * Replace the chart filter. This is equivalent to calling `chart.filter(null).filter(filter)`
     * but more efficient because the filter is only applied once.
     *
     * @method replaceFilter
     * @memberof dc.baseMixin
     * @instance
     * @param {*} [filter]
     * @returns {dc.baseMixin}
     **/
    _chart.replaceFilter = function (filter) {
        _filters = _resetFilterHandler(_filters);
        _chart.filter(filter);
        return _chart;
    };

    /**
     * Filter the chart by the given parameter, or return the current filter if no input parameter
     * is given.
     *
     * The filter parameter can take one of these forms:
     * * A single value: the value will be toggled (added if it is not present in the current
     * filters, removed if it is present)
     * * An array containing a single array of values (`[[value,value,value]]`): each value is
     * toggled
     * * When appropriate for the chart, a {@link dc.filters dc filter object} such as
     *   * {@link dc.filters.RangedFilter `dc.filters.RangedFilter`} for the
     * {@link dc.coordinateGridMixin dc.coordinateGridMixin} charts
     *   * {@link dc.filters.TwoDimensionalFilter `dc.filters.TwoDimensionalFilter`} for the
     * {@link dc.heatMap heat map}
     *   * {@link dc.filters.RangedTwoDimensionalFilter `dc.filters.RangedTwoDimensionalFilter`}
     * for the {@link dc.scatterPlot scatter plot}
     * * `null`: the filter will be reset using the
     * {@link dc.baseMixin#resetFilterHandler resetFilterHandler}
     *
     * Note that this is always a toggle (even when it doesn't make sense for the filter type). If
     * you wish to replace the current filter, either call `chart.filter(null)` first - or it's more
     * efficient to call {@link dc.baseMixin#replaceFilter `chart.replaceFilter(filter)`} instead.
     *
     * Each toggle is executed by checking if the value is already present using the
     * {@link dc.baseMixin#hasFilterHandler hasFilterHandler}; if it is not present, it is added
     * using the {@link dc.baseMixin#addFilterHandler addFilterHandler}; if it is already present,
     * it is removed using the {@link dc.baseMixin#removeFilterHandler removeFilterHandler}.
     *
     * Once the filters array has been updated, the filters are applied to the
     * crossfilter dimension, using the {@link dc.baseMixin#filterHandler filterHandler}.
     *
     * Once you have set the filters, call {@link dc.baseMixin#redrawGroup `chart.redrawGroup()`}
     * (or {@link dc.redrawAll `dc.redrawAll()`}) to redraw the chart's group.
     * @method filter
     * @memberof dc.baseMixin
     * @instance
     * @see {@link dc.baseMixin#addFilterHandler addFilterHandler}
     * @see {@link dc.baseMixin#removeFilterHandler removeFilterHandler}
     * @see {@link dc.baseMixin#resetFilterHandler resetFilterHandler}
     * @see {@link dc.baseMixin#filterHandler filterHandler}
     * @example
     * // filter by a single string
     * chart.filter('Sunday');
     * // filter by a single age
     * chart.filter(18);
     * // filter by a set of states
     * chart.filter([['MA', 'TX', 'ND', 'WA']]);
     * // filter by range -- note the use of dc.filters.RangedFilter, which is different
     * // from the syntax for filtering a crossfilter dimension directly, dimension.filter([15,20])
     * chart.filter(dc.filters.RangedFilter(15,20));
     * @param {*} [filter]
     * @returns {dc.baseMixin}
     */
    _chart.filter = function (filter) {
        if (!arguments.length) {
            return _filters.length > 0 ? _filters[0] : null;
        }
        var filters = _filters;
        if (filter instanceof Array && filter[0] instanceof Array && !filter.isFiltered) {
            // toggle each filter
            filter[0].forEach(function (f) {
                if (_hasFilterHandler(filters, f)) {
                    filters = _removeFilterHandler(filters, f);
                } else {
                    filters = _addFilterHandler(filters, f);
                }
            });
        } else if (filter === null) {
            filters = _resetFilterHandler(filters);
        } else {
            if (_hasFilterHandler(filters, filter)) {
                filters = _removeFilterHandler(filters, filter);
            } else {
                filters = _addFilterHandler(filters, filter);
            }
        }
        _filters = applyFilters(filters);
        _chart._invokeFilteredListener(filter);

        if (_root !== null && _chart.hasFilter()) {
            _chart.turnOnControls();
        } else {
            _chart.turnOffControls();
        }

        return _chart;
    };

    /**
     * Returns all current filters. This method does not perform defensive cloning of the internal
     * filter array before returning, therefore any modification of the returned array will effect the
     * chart's internal filter storage.
     * @method filters
     * @memberof dc.baseMixin
     * @instance
     * @returns {Array<*>}
     */
    _chart.filters = function () {
        return _filters;
    };

    _chart.highlightSelected = function (e) {
        d3.select(e).classed(dc.constants.SELECTED_CLASS, true);
        d3.select(e).classed(dc.constants.DESELECTED_CLASS, false);
    };

    _chart.fadeDeselected = function (e) {
        d3.select(e).classed(dc.constants.SELECTED_CLASS, false);
        d3.select(e).classed(dc.constants.DESELECTED_CLASS, true);
    };

    _chart.resetHighlight = function (e) {
        d3.select(e).classed(dc.constants.SELECTED_CLASS, false);
        d3.select(e).classed(dc.constants.DESELECTED_CLASS, false);
    };

    /**
     * This function is passed to d3 as the onClick handler for each chart. The default behavior is to
     * filter on the clicked datum (passed to the callback) and redraw the chart group.
     *
     * This function can be replaced in order to change the click behavior (but first look at 
     * @method onClick
     * @memberof dc.baseMixin
     * @instance
     * @example
     * var oldHandler = chart.onClick;
     * chart.onClick = function(datum) {
     *   // use datum.
     * @param {*} datum
     * @return {undefined}
     */
    _chart.onClick = function (datum) {
        var filter = _chart.keyAccessor()(datum);
        dc.events.trigger(function () {
            _chart.filter(filter);
            _chart.redrawGroup();
        });
    };

    /**
     * Set or get the filter handler. The filter handler is a function that performs the filter action
     * on a specific dimension. Using a custom filter handler allows you to perform additional logic
     * before or after filtering.
     * @method filterHandler
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://github.com/crossfilter/crossfilter/wiki/API-Reference#dimension_filter crossfilter.dimension.filter}
     * @example
     * // the default filter handler handles all possible cases for the charts in dc.js
     * // you can replace it with something more specialized for your own chart
     * chart.filterHandler(function (dimension, filters) {
     *     if (filters.length === 0) {
     *         // the empty case (no filtering)
     *         dimension.filter(null);
     *     } else if (filters.length === 1 && !filters[0].isFiltered) {
     *         // single value and not a function-based filter
     *         dimension.filterExact(filters[0]);
     *     } else if (filters.length === 1 && filters[0].filterType === 'RangedFilter') {
     *         // single range-based filter
     *         dimension.filterRange(filters[0]);
     *     } else {
     *         // an array of values, or an array of filter objects
     *         dimension.filterFunction(function (d) {
     *             for (var i = 0; i < filters.length; i++) {
     *                 var filter = filters[i];
     *                 if (filter.isFiltered && filter.isFiltered(d)) {
     *                     return true;
     *                 } else if (filter <= d && filter >= d) {
     *                     return true;
     *                 }
     *             }
     *             return false;
     *         });
     *     }
     *     return filters;
     * });
     *
     * // custom filter handler
     * chart.filterHandler(function(dimension, filter){
     *     var newFilter = filter + 10;
     *     dimension.filter(newFilter);
     *     return newFilter; // set the actual filter value to the new value
     * });
     * @param {Function} [filterHandler]
     * @returns {Function|dc.baseMixin}
     */
    _chart.filterHandler = function (filterHandler) {
        if (!arguments.length) {
            return _filterHandler;
        }
        _filterHandler = filterHandler;
        return _chart;
    };

    // abstract function stub
    _chart._doRender = function () {
        // do nothing in base, should be overridden by sub-function
        return _chart;
    };

    _chart._doRedraw = function () {
        // do nothing in base, should be overridden by sub-function
        return _chart;
    };

    _chart.legendables = function () {
        // do nothing in base, should be overridden by sub-function
        return [];
    };

    _chart.legendHighlight = function () {
        // do nothing in base, should be overridden by sub-function
    };

    _chart.legendReset = function () {
        // do nothing in base, should be overridden by sub-function
    };

    _chart.legendToggle = function () {
        // do nothing in base, should be overriden by sub-function
    };

    _chart.isLegendableHidden = function () {
        // do nothing in base, should be overridden by sub-function
        return false;
    };

    /**
     * Set or get the key accessor function. The key accessor function is used to retrieve the key
     * value from the crossfilter group. Key values are used differently in different charts, for
     * example keys correspond to slices in a pie chart and x axis positions in a grid coordinate chart.
     * @method keyAccessor
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // default key accessor
     * chart.keyAccessor(function(d) { return d.key; });
     * // custom key accessor for a multi-value crossfilter reduction
     * chart.keyAccessor(function(p) { return p.value.absGain; });
     * @param {Function} [keyAccessor]
     * @returns {Function|dc.baseMixin}
     */
    _chart.keyAccessor = function (keyAccessor) {
        if (!arguments.length) {
            return _keyAccessor;
        }
        _keyAccessor = keyAccessor;
        return _chart;
    };

    /**
     * Set or get the value accessor function. The value accessor function is used to retrieve the
     * value from the crossfilter group. Group values are used differently in different charts, for
     * example values correspond to slice sizes in a pie chart and y axis positions in a grid
     * coordinate chart.
     * @method valueAccessor
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // default value accessor
     * chart.valueAccessor(function(d) { return d.value; });
     * // custom value accessor for a multi-value crossfilter reduction
     * chart.valueAccessor(function(p) { return p.value.percentageGain; });
     * @param {Function} [valueAccessor]
     * @returns {Function|dc.baseMixin}
     */
    _chart.valueAccessor = function (valueAccessor) {
        if (!arguments.length) {
            return _valueAccessor;
        }
        _valueAccessor = valueAccessor;
        return _chart;
    };

    /**
     * Set or get the label function. The chart class will use this function to render labels for each
     * child element in the chart, e.g. slices in a pie chart or bubbles in a bubble chart. Not every
     * chart supports the label function, for example line chart does not use this function
     * at all. By default, enables labels; pass false for the second parameter if this is not desired.
     * @method label
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // default label function just return the key
     * chart.label(function(d) { return d.key; });
     * // label function has access to the standard d3 data binding and can get quite complicated
     * chart.label(function(d) { return d.data.key + '(' + Math.floor(d.data.value / all.value() * 100) + '%)'; });
     * @param {Function} [labelFunction]
     * @param {Boolean} [enableLabels=true]
     * @returns {Function|dc.baseMixin}
     */
    _chart.label = function (labelFunction, enableLabels) {
        if (!arguments.length) {
            return _label;
        }
        _label = labelFunction;
        if ((enableLabels === undefined) || enableLabels) {
            _renderLabel = true;
        }
        return _chart;
    };

    /**
     * Turn on/off label rendering
     * @method renderLabel
     * @memberof dc.baseMixin
     * @instance
     * @param {Boolean} [renderLabel=false]
     * @returns {Boolean|dc.baseMixin}
     */
    _chart.renderLabel = function (renderLabel) {
        if (!arguments.length) {
            return _renderLabel;
        }
        _renderLabel = renderLabel;
        return _chart;
    };

    /**
     * Set or get the title function. The chart class will use this function to render the SVGElement title
     * (usually interpreted by browser as tooltips) for each child element in the chart, e.g. a slice
     * in a pie chart or a bubble in a bubble chart. Almost every chart supports the title function;
     * however in grid coordinate charts you need to turn off the brush in order to see titles, because
     * otherwise the brush layer will block tooltip triggering.
     * @method title
     * @memberof dc.baseMixin
     * @instance
     * @example
     * // default title function shows "key: value"
     * chart.title(function(d) { return d.key + ': ' + d.value; });
     * // title function has access to the standard d3 data binding and can get quite complicated
     * chart.title(function(p) {
     *    return p.key.getFullYear()
     *        + '\n'
     *        + 'Index Gain: ' + numberFormat(p.value.absGain) + '\n'
     *        + 'Index Gain in Percentage: ' + numberFormat(p.value.percentageGain) + '%\n'
     *        + 'Fluctuation / Index Ratio: ' + numberFormat(p.value.fluctuationPercentage) + '%';
     * });
     * @param {Function} [titleFunction]
     * @returns {Function|dc.baseMixin}
     */
    _chart.title = function (titleFunction) {
        if (!arguments.length) {
            return _title;
        }
        _title = titleFunction;
        return _chart;
    };

    /**
     * Turn on/off title rendering, or return the state of the render title flag if no arguments are
     * given.
     * @method renderTitle
     * @memberof dc.baseMixin
     * @instance
     * @param {Boolean} [renderTitle=true]
     * @returns {Boolean|dc.baseMixin}
     */
    _chart.renderTitle = function (renderTitle) {
        if (!arguments.length) {
            return _renderTitle;
        }
        _renderTitle = renderTitle;
        return _chart;
    };

    /**
     * A renderlet is similar to an event listener on rendering event. Multiple renderlets can be added
     * to an individual chart.  Each time a chart is rerendered or redrawn the renderlets are invoked
     * right after the chart finishes its transitions, giving you a way to modify the SVGElements.
     * Renderlet functions take the chart instance as the only input parameter and you can
     * use the dc API or use raw d3 to achieve pretty much any effect.
     *
     * Use {@link dc.baseMixin#on on} with a 'renderlet' prefix.
     * Generates a random key for the renderlet, which makes it hard to remove.
     * @method renderlet
     * @memberof dc.baseMixin
     * @instance
     * @deprecated
     * @example
     * // do this instead of .renderlet(function(chart) { ... })
     * chart.on("renderlet", function(chart){
     *     // mix of dc API and d3 manipulation
     *     chart.select('g.y').style('display', 'none');
     *     // its a closure so you can also access other chart variable available in the closure scope
     *     moveChart.filter(chart.filter());
     * });
     * @param {Function} renderletFunction
     * @returns {dc.baseMixin}
     */
    _chart.renderlet = dc.logger.deprecate(function (renderletFunction) {
        _chart.on('renderlet.' + dc.utils.uniqueId(), renderletFunction);
        return _chart;
    }, 'chart.renderlet has been deprecated.  Please use chart.on("renderlet.<renderletKey>", renderletFunction)');

    /**
     * Get or set the chart group to which this chart belongs. Chart groups are rendered or redrawn
     * together since it is expected they share the same underlying crossfilter data set.
     * @method chartGroup
     * @memberof dc.baseMixin
     * @instance
     * @param {String} [chartGroup]
     * @returns {String|dc.baseMixin}
     */
    _chart.chartGroup = function (chartGroup) {
        if (!arguments.length) {
            return _chartGroup;
        }
        if (!_isChild) {
            dc.deregisterChart(_chart, _chartGroup);
        }
        _chartGroup = chartGroup;
        if (!_isChild) {
            dc.registerChart(_chart, _chartGroup);
        }
        return _chart;
    };

    /**
     * Expire the internal chart cache. dc charts cache some data internally on a per chart basis to
     * speed up rendering and avoid unnecessary calculation; however it might be useful to clear the
     * cache if you have changed state which will affect rendering.  For example, if you invoke
     * {@link https://github.com/crossfilter/crossfilter/wiki/API-Reference#crossfilter_add crossfilter.add}
     * function or reset group or dimension after rendering, it is a good idea to
     * clear the cache to make sure charts are rendered properly.
     * @method expireCache
     * @memberof dc.baseMixin
     * @instance
     * @returns {dc.baseMixin}
     */
    _chart.expireCache = function () {
        // do nothing in base, should be overridden by sub-function
        return _chart;
    };

    /**
     * Attach a dc.legend widget to this chart. The legend widget will automatically draw legend labels
     * based on the color setting and names associated with each group.
     * @method legend
     * @memberof dc.baseMixin
     * @instance
     * @example
     * chart.legend(dc.legend().x(400).y(10).itemHeight(13).gap(5))
     * @param {dc.legend} [legend]
     * @returns {dc.legend|dc.baseMixin}
     */
    _chart.legend = function (legend) {
        if (!arguments.length) {
            return _legend;
        }
        _legend = legend;
        _legend.parent(_chart);
        return _chart;
    };

    /**
     * Returns the internal numeric ID of the chart.
     * @method chartID
     * @memberof dc.baseMixin
     * @instance
     * @returns {String}
     */
    _chart.chartID = function () {
        return _chart.__dcFlag__;
    };

    /**
     * Set chart options using a configuration object. Each key in the object will cause the method of
     * the same name to be called with the value to set that attribute for the chart.
     * @method options
     * @memberof dc.baseMixin
     * @instance
     * @example
     * chart.options({dimension: myDimension, group: myGroup});
     * @param {{}} opts
     * @returns {dc.baseMixin}
     */
    _chart.options = function (opts) {
        var applyOptions = [
            'anchor',
            'group',
            'xAxisLabel',
            'yAxisLabel',
            'stack',
            'title',
            'point',
            'getColor',
            'overlayGeoJson'
        ];

        for (var o in opts) {
            if (typeof(_chart[o]) === 'function') {
                if (opts[o] instanceof Array && applyOptions.indexOf(o) !== -1) {
                    _chart[o].apply(_chart, opts[o]);
                } else {
                    _chart[o].call(_chart, opts[o]);
                }
            } else {
                dc.logger.debug('Not a valid option setter name: ' + o);
            }
        }
        return _chart;
    };

    /**
     * All dc chart instance supports the following listeners.
     * Supports the following events:
     * * `renderlet` - This listener function will be invoked after transitions after redraw and render. Replaces the
     * deprecated {@link dc.baseMixin#renderlet renderlet} method.
     * * `pretransition` - Like `.on('renderlet', ...)` but the event is fired before transitions start.
     * * `preRender` - This listener function will be invoked before chart rendering.
     * * `postRender` - This listener function will be invoked after chart finish rendering including
     * all renderlets' logic.
     * * `preRedraw` - This listener function will be invoked before chart redrawing.
     * * `postRedraw` - This listener function will be invoked after chart finish redrawing
     * including all renderlets' logic.
     * * `filtered` - This listener function will be invoked after a filter is applied, added or removed.
     * * `zoomed` - This listener function will be invoked after a zoom is triggered.
     * @method on
     * @memberof dc.baseMixin
     * @instance
     * @see {@link https://github.com/d3/d3-dispatch/blob/master/README.md#dispatch_on d3.dispatch.on}
     * @example
     * .on('renderlet', function(chart, filter){...})
     * .on('pretransition', function(chart, filter){...})
     * .on('preRender', function(chart){...})
     * .on('postRender', function(chart){...})
     * .on('preRedraw', function(chart){...})
     * .on('postRedraw', function(chart){...})
     * .on('filtered', function(chart, filter){...})
     * .on('zoomed', function(chart, filter){...})
     * @param {String} event
     * @param {Function} listener
     * @returns {dc.baseMixin}
     */
    _chart.on = function (event, listener) {
        _listeners.on(event, listener);
        return _chart;
    };

    return _chart;
};