How to set tree max level in V4+ trees?

Question

I have a tree and I want it to initally open up to level 3. (Not expand all). Previous to V4 you could set the attribute "Max Levels". How do you set this now? I assume it will be a dynamic action javascript call but what is the code?
thanks in advance
PaulP
Edited by: PaulP on Apr 5, 2012 11:13 PM
Edited by: PaulP on Apr 5, 2012 11:14 PM

Answer 1

I searched through the docs of jstree 0.9.9a2, which comes with apex 4+, and through apex.widget.tree, but couldn't find any function which does what you describe. However, it can be emulated fairly easily.
Add this code to the page javascript:
function resetAndOpenToLevel ( pTree, pMaxLevel ) {
   apex.jQuery.tree.reference(pTree).close_all();
   $("ul", pTree).each(function ( index ) {
      if ( $(this).parents("ul").length <= pMaxLevel ) {
         apex.jQuery.tree.reference(pTree).open_branch(this);
};When called this will open up the nodes of the given tree up to (and including) pMaxLevel.
For convenience, give your tree region a static ID.
For example,define a button which triggers a dynamic action with execute javascript code as true action:
resetAndOpenToLevel ( $("#my_tree_region_id div.tree"), 2) ;Would reset the tree, and then open nodes up to and including level 2.
You can try it out on my example tree page, where i included this code: http://apex.oracle.com/pls/apex/f?p=54687:38 There I'm using a global javascript variable to store a reference to the tree element rather than fetching it every time.