Treeview Load On Demand

2 posts, 0 answers
  1. Paul
    Paul  avatar
    9 posts
    Member since:
    Jan 2011

    Posted 30 Mar 2012 Link to this post

    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.

  2. Christopher
    Christopher avatar
    10 posts
    Member since:
    Mar 2012

    Posted 31 Mar 2012 Link to this post

    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.
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