flex chart data change events

[Solerous]

I need to capture an event for when the data is updated in a chart. I take a
snapshot of the chart and save it to a file. But when I do it via a custom
event which I fire myself, it fires the event and takes the screenshot before
the update and so just snapshots the previous state of the chart. And if I use
FlexEvent.UPDATE_COMPLETE, it doesn't register a change since what I am doing
is adding data to the array which is the dataProvider for the chart.
I can't put an update event listener to the array itself since the array does
not have any way to reference back to it's chart.

Any help would be greatly appreciated!