I'm trying to create a DataGrid headerRenderer with a TextInput to filter the
grid from the column. The custom renderer simply has a label (with the column
header label) and then a text input, and it's all in AS, implementing IFactory,
etc. It's rendering just fine.

The issue is with the filtering - at first, I tried just adding the text box,
but as soon as I typed anything in it, the filtering logic (which must call
dataProvider.refresh() to refresh the dataGrid) caused the header to be
re-instantiated, thereby clearing the filter text input field. I later worked
around this by caching the TextInput objects elsewhere, and having the header
simply addChild on them.

However, the issue still gets in the way. The headerRenderer is reinstantiated
twice per call to refresh(), causing it to blink, and if the user types too
fast, it throws a RTE because the components haven't been instantiated yet.

Is there a way to stop this incessant re-initialization of the headerRenderer?
It doesn't seem necessary or efficient. If anyone knows or wants to help I
would be very grateful. Thanks!

This may be caused by the TextInput event you are using to call the filtering
method. Are you call your filtering method from the TextInput's change event,
perhaps? If so, each character being typed will call the filter method. Call
your filtering method from the valueCommit event, and see if that helps.

Put a break on the first line of your filter method, debug the app, start
typing into the TextInput and watch what happens. If the filter method is
called multiple times this could be the problem.

Be sure you don't call the filter method until the typing is completed.

That makes sense, but I had really wanted to attach it to the keyUp event so
that it would filter on each keystroke. Filtering on some submit action or once
the full input is complete is an acceptable compromise.