Optional printing of data value in popover

[flxReinoud]

The data value of a bubble was always printed in the popover. We needed to disable the printing of the data in the popover because the absolute values were not relevant for a few of our graphs. This was caused by the absolute values be approximations. This pull request introduces a key in the popoverOpts configuration dict with the name popoverShowData which can be set to false to disable the printing of data in the popover.

[jondavidjohn]

Thanks for this. Seems like an interesting approach and certainly fits your needs, but I think it's not quite generic enough a solution.

I'd like to see this solved with a detailTemplate potentially, where we allow the user to specify how the popover text should be displayed. Something like...

var chart = new BubbleChart({
  canvasId: "bubblechart",
  metric: "Kb",
  usedArea: 0.35,
  contain: true,
  popoverOpts: {
    textFont: "Open Sans",
    detailTemplate: "{data} {metric}" // <------------- Default
  },
  data : myCustomData()
});

That way it would solve your case (by providing just "{metric}") but it would also solve many other custom implementations.

For example if someone is doing work with percentages and they want the metric first.

    detailTemplate: "{metric} {data}%"

[jondavidjohn]

Also, make sure all pull requests are targeted at the develop branch. Thanks!

(should probably update CONTRIBUTING.md)