We need the ability to incrementally load child elements of tree nodes OnDemand. Large enterprise hiearchies require this to reduce the load time for the tree branches that users may never uses. Do you plan to formally support this type of event and if so when it might be available.
First I agree with Paul that this is a nearly necessary feature for any large tree.
This *might* be part of the planned extension to trees, but if not. please include it.
Here's some details that I hope you'll take into account.
First, Now when a tree node has no children, the triangle disappears.
If we have "load on demand" for children, there's really 3 states for the triangle:
1. expanded
2. collapsed has children
3. collapsed don't know if there's children or not, wait for the user to expand.
I call this state "unloaded".
The application I have in mind needs to load children only as needed,
and the tree may be changing on the server while a user is loolking at it.
(ie other users are editing it)
I have a way to update the users view, (appengine channel) but even so,
I think a collapse then expand of the triangle should "refresh" the children.
If the triangle goes away just because the client thinks there are no children,
the user will have no way to refresh it. I don't mind having a down (expanded) triangle
be visible even when there are no children. It gives the user something to click
on to refresh.
My next issue *might* be related because it has to do with nodes with no children I think.
If you have a simple tree that has just 2 nodes, both at top level.
and you wnat to drag the 2nd node to become a child of the first, you can't.
There's a bunch of other scenarios where you can't drag a node to where you want it
within the tree when moving the node down a level. I've notice for instance when
you want to move a node to the last node in a 2 level tree, you might want to make
it the last top level sibling, or you might want to make it a child of the last top level node.
This means there would have to be 2 drop targets at the bottom of the tree.
If I am doing something wrong as a user, then MY users aren't going
to be able to figure it out either. If this is an "ommission" rather than a bug, well,
its a significantly limiting one for my app.
Since the datasource updates to the treeview didn't happen in the end of march 2012 release,
does that mean we have to wait another 4 months for the next release for those features?
Finally a complement: Organizing the forums by class is something that I've thought of
for at least a decade and rarely seen it. Great idea.
Also I like the voting for your favorite features to be added.