onClick (and other events) for line charts with slice tooltips

[netbizltd]

Just kicked out the old Google charts and updated everything to nivo in one of my projects ... and then realized that onClick doesn't work when having slice tooltips enabled (which are so nice for stacked line charts).

It would be great to at least get the x axis value from onClick (and maybe other) events since I use that to update other dependent charts, eg: X Axis contains a date value => update a pie chart filtered on the selected date.

How about that?