Extjs: Tree, Selecting node after creating the tree

I have a simple TreePanel. I would like to select a particular node upon loading it. The nodes are from a remote file (json).

The tree is loading as expected. However, the node is not being selected.开发者_StackOverflow Firebug shows node as undefined. This perhaps because of the async property. But, I an unable to configure this other wise, or specify the node be selected.

Any suggestions welcomed, and thank you.

    LeftMenuTree = new Ext.tree.TreePanel({
    renderTo: 'TreeMenu',
    collapsible: false,
    height: 450,
    border: false,
    userArrows: true,
    animate: true,
    autoScroll: true,
    id: 'testtest',
    dataUrl: fileName,
    root: {
  nodeType: 'async',    
     iconCls:'home-icon',
     expanded:true,
       text: rootText
    },
    listeners: {
        "click": {
    fn: onPoseClick,
                 scope: this
               }
        },
          "afterrender": {
       fn: setNode,
       scope: this 
      }  
 });
function setNode(){
 alert (SelectedNode);
  if (SelectedNode == "Orders"){
    var treepanel = Ext.getCmp('testtest');
    var node = treepanel.getNodeById("PendingItems");
    node.select();
  }
} 

---

I use this code in the TreeGrid to select a node

_I.treeGrid.getSelectionModel().select(_I.treeGrid.getRootNode());

I haven't tried this in a TreePanel but since the TreeGrid is based on it I'll just assume this works. I used the load event of the loader to plugin similar code after the XHR request was done, so try to write your setNode function like this:

var loader = LeftMenuTree.getLoader();
loader.on("load", setNode);    
function setNode(){
     alert (SelectedNode);
      if (SelectedNode == "Orders"){
        var treepanel = Ext.getCmp('testtest');
        treepanel.getSelectionModel().select(treepanel.getNodeById("PendingItems"));
      }
    }

---

this work for me...

var loader  = Ext.getCmp('testtest').getLoader();
loader.on("load", function(a,b,c){ 
   b.findChild("id",1, true).select(); // can find by any parameter in the json
}); 

---

I have documented a way to accomplish something very similar here:

http://www.sourcepole.ch/2010/9/28/understanding-what-s-going-on-in-extjs

what you'll need to make sure is that the node that you are selecting is visible. You can accomplish that by traversing the tree and node.expand()ing all the nodes parents (from the root down).

---

This is because the node isn't really selectable until the tree has been rendered. Try adding your node selection to an event listener listening for the render event.

---

If you're using a recent enough version of ExtJS then I find using ViewModels and the Selection config far easier for this kind of thing.

Something like:

LeftMenuTree = new Ext.tree.TreePanel({
renderTo: 'TreeMenu',
collapsible: false,
height: 450,
border: false,
userArrows: true,
animate: true,
autoScroll: true,
id: 'testtest',
dataUrl: fileName,
bind: {
    Selection: '{SelectedNode}'
}, 
root: {
   nodeType: 'async',    
   iconCls:'home-icon',
   expanded:true,
   text: rootText
},
listeners: {
    "click": {
       fn: onPoseClick,
       scope: this
    }
    "afterrender": {
       fn: setNode,
       scope: this 
    }  
 });

(You'll need to either have a ViewModel set up in the TreePanel or the owning view)

Then assuming you're using a ViewController and setNode is a member:

setNode: function(){
 var nodeToSelect = // code to find the node object here
 this.getViewModel().set('Selection', nodeToSelect);
} 

The nice thing about the ViewModel approach is that it seems to just handle all of the rendering / data loading issues automatically.