I agree completely with deepak here. I understand that to obtain data in children, we need to turn off loadOnDemand. However, doing so, even with inline data, causes the browser to become unresponsive.
I created a simple JSBin
to show what I'm doing in an attempt to reproduce the issue. It seems to work very nicely in Chrome (currently version 31). It does not work as nicely in FireFox 25.0.1 or IE10. The JSBin DOES work a hair faster than the development I'm doing, but if you watch closely, you'll still see FF or IE temporarily "Not Respond."
Please tell me there's a way around this? I need to be able to read the entire data source upon initial load. Or is there an expanding/expanded (yes, both) event? (I would like to show a progress icon when the user expands a node and turn it off when it's loaded. I'd also like to see the children items immediately after expand.)