Zoom event

I would like to update gauges when the zoom changes. It would be great to be able to catch an event, something like:

myChart.onZoom(function (x, y, data){
    //doSomething
});

Thanks

[buddyp450]

I’ve submitted a PR request - it was pretty easy to implement. Note that the callbacks are invoked after the chart instance’s update call.

[buddyp450]

ChartJS uses momentjs for it’s time ranges so in my implementations I’m just filtering down the original dataset using isBetween(startDate, endDate)