Retrieve tree's states after load

I updating my tree and to synchronize this with my J开发者_如何学GoSON i using methods :

mystore.sync(); mystore.load();

If i don't using the second method, the tree don't show modifications ! With load method, tree collapse and the updates are effectives. But tree collapse even though before it was expand . How to restore state before load ??

Thanks a lot :)

You can send list of expanded items to server, and generate your json with 'expanded: ture' according to expanded list.