The case of the mysterious non-expanding tree.

Question

Hello all,
I've got a strange problem that I can't figure out. At it's
simplest, i've got a tree and two xml objects. In mx tag for the
tree I define one of the xml objects as the dataprovider,
additionally i've defined an event handler for the trees
creationComplete event that opens up the root nood. This works
great and is exactly what I want.
But...
I've also got a button, click on the button and it either a)
changes the dataprovider of the tree to the second xml object, or
b) change the xml in the dataprovider already assigned. Then,
because the data has changed and the tree re-renders it ends up
collapsed again so immediately after changing it's data I try to
open the root node but nothing happens. No errors, just nothing.
For the purpose of debugging i added a second button that
simply tries to expand the root node of the tree after i've changed
the trees data provider and it works fine. The line of code that
exists in both the first and second buttons and that should open
the tree only works in the second button for some reason. The only
thing I can think of is timing, perhaps when trying to expand the
node in the line of code directly following the change to the
dataprovider the data hasn't loaded into the tree yet so it can't
expand the node but, i've tried all sorts of event handlers and
they don't seem to work either.
Here's a link if someone wants to download my test.mxml file
and try it themselves. There's more comments in the code but it's a
super simple test page so it should be immediate where the problem
is...
http://www.binarydemon.com/test.mxml
Thanks in advance.
Zach

Answer 1

Thanks Tracy,
callLater() was exactly what I needed. I had no idea that
method even existed, most things have events that fire when
something important happens that I want to respond to, or are timed
better for me to respond to that I've yet to need callLater(). Of
course I'm still new at flex...
Best,
Zach.