Why is it null?

3 posts, 0 answers
  1. Bruno
    Bruno avatar
    11 posts
    Member since:
    Jan 2009

    Posted 16 Sep 2009 Link to this post

    Hi guys,

    I have a tree view and I use a call to Expand only the first level so the user can see the first node expended.

    IE, Safari and Chrome do not see RadTreeView only FF and Opera

    What am I doing wrong here?


    The RadTreeView

    <telerik:RadTreeView ID="RadTreeView" runat="server" OnNodeDataBound="RadTreeView_NodeDataBound"
        OnClientNodeClicked="onClientNodeClickedHandler" OnClientMouseOver="onClientMouseOverHandler"
        CheckBoxes="false" CheckChildNodes="false" MultipleSelect="true" TriStateCheckBoxes="false"
        SingleExpandPath="true" BorderColor="LightGray" BorderWidth="0">

    The call

    $(document).ready(function() {
       // expand until level

       function treeExpandNodes(level) {
          var treeView = $find('<%= RadTreeView.ClientID %>');
          if (treeView != null) {
             var nodes = treeView.get_allNodes();

             for (var i = 0; i < nodes.length; i++) {
                if (nodes[i].get_nodes() != null) {
                   if (nodes[i].get_level() <= level)
             alert('Why is it null?'); // only in FF and Opera this alert is not called!

    image of the output in the 4 browsers

  2. Bruno
    Bruno avatar
    11 posts
    Member since:
    Jan 2009

    Posted 16 Sep 2009 Link to this post

    it will work if I delay the call by 100 ms

          setTimeout(function() { treeExpandNodes(0); }, 100);

    the DOM is already created, should be immediately as I could see the flick of the RadTreeView showing the first node (All Collapsed) and then the expanded until the level I wanted.

  3. UI for ASP.NET Ajax is Ready for VS 2017
  4. Veselin Vasilev
    Veselin Vasilev avatar
    2992 posts

    Posted 17 Sep 2009 Link to this post

    Hi Bruno,

    The document ready state is a little bit early in the page life cycle and the client objects are not yet initialized. That is why it works when a timeout is added.
    The safest way would be to use the pageLoad or the Sys.Application.add_load() method:

    function pageLoad() 

    All the best,
    Veselin Vasilev
    the Telerik team

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