How to call Highcharts tooltip formatter function from outside the config object?
<p>so I have an interesting problem.</p>

<p>Here is where the formatter function is inside of the chart config object:</p>

<p><strong>In HighCharts Controller</strong></p>

<pre><code>vm.config = {
    options: {
        ....
        chart: {
            ....
        },
        navigator: {
            ....
        },
        tooltip: {
            shared: true,
            useHTML: true,
            backgroundColor: null,
            borderWidth: 0,
            shadow: false,
            formatter: function(tooltipObj) {
                return formatTooltip(tooltipObj, this.points);
            }
        },
        ....
</code></pre>

<p>I would love to be able to call the <code>formatTooltip</code> function from another place in my app. However, 1) How do I do that? and 2) How do I pass in the <code>tooltipObj</code>?</p>

<p>For example inside of my alertFactory I want the mouseover event that happens when the user hovers over a plotBand, to send more information into the tooltip:</p>

<p><strong>In AlertsFactory</strong></p>

<pre><code>var formatPlotBand = _.curry((color, alert) =&gt; {
    return {
        color : color,
        from  : alert.start_epoch * 1000,
        to    : alert.end_epoch * 1000,
        id    :'alert-plotband',
        events: {
            mouseover: function (e) {
                /*
                    Somehow from here call the formatTooltip function
                    in the highCharts Controller.
                */
            },
            mouseout: function (e) {
                ....
</code></pre>