C3 charts - contents of tooltip clickable

I am making charts using c3.js. I have to make the contents of the tooltip cilckable. Till now, the tooltip is visible only when i hover over the chart. I have some Information which is to be displayed when i click on a link in the tooltip. I couldn't find any help from c3 documentation. Snippet of the code i am working on is shown below.

$scope.timelineConfig.tooltip.contents = function (data, defaultTitleFormat, defaultValueFormat, color) {
    var $$ = this, config = $$.config,
    titleFormat = config.tooltip_format_title || defaultTitleFormat,
    nameFormat = config.tooltip_format_name || function (name) { return name; },
    valueFormat = config.tooltip_format_value || defaultValueFormat,
    text, i, title, value;
    text = "<div id='tooltip' class='d3-tip'>"; 
    title = dates[data[0].index];
    text += "<span class='info'><b><u>Date</u></b></span><br>";
    text += "<span class='info'>"+ title +"</span><br>";
    text += "<span class='info'><b><u>Features</u> : </b> " + features[data[0].index] + "</span><br>";
    text += "<span class='info'><b><u>Enhancements</u> : </b> " + defects[data[0].index] + "</span><br>";
    text += "</div>";
    return text;
};

I have to make the contents (Features...) clickable.

Solution

First (if you haven't already done so) override the tooltip position so that it doesn't keep running away when you try to click it.

tooltip: {
    position: function () {
        var position = c3.chart.internal.fn.tooltipPosition.apply(this, arguments);
        position.top = 0;
        return position;
    },

Then you need to override the hideTooltip function so that it doesn't close before your click event can be detected.

var originalHideTooltip = chart.internal.hideTooltip
chart.internal.hideTooltip = function () {
    setTimeout(originalHideTooltip, 100)
};

Then, you just need to override the pointer-events style (so that the mouse events are not ignored) and then attach the handler as you normally would in jQuery

$(".c3-tooltip-container")
    .css("pointer-events", "auto")
    .on('click', '.info:eq(2)', function () {
        // add click functionality here. you could pass in additional data using the span attributes
        alert($(this).text())
    })

Modify the selector as required (like adding the chart wrapper id...)

Fiddle - http://jsfiddle.net/5vbeb4k8/