Within the Splunk Web Framework there needs to be a click:label event that is fired everytime a label is clicked on a chart.
When there are very small slivers of a pie chart for example or on a bar chart the slivers may not be there if the number is small enough.
It would be much easier to fire off an event based on the word that stays the same size.
This may be in d3.js charts, but I think it would be a great addition to the oob django charts.
I also think that it should show the name of the label on hover, as that one label that is super long, you will not know what it says unless you hover over the bar.
Callout labels on pie chart slices can now be clicked in the development version of Splunk. Therefore you should see this functionality in the next Splunk release.
The label clicks come through on the regular "click" event.
Can you also put a request to change label text while rendering any chart, See http://answers.splunk.com/answers/189183/bar-chart-x-axis-label-text-change.html
Let me know if there is any existing way of doing so