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Observable
  TreeLoader

Class Ext.tree.TreeLoader

Package:Ext.tree
Defined In:TreeLoader.js
Class:TreeLoader
Extends:Observable
A TreeLoader provides for lazy loading of an Ext.tree.TreeNode's child nodes from a specified URL. The response must be a JavaScript Array definition whose elements are node definition objects. e.g.:
[{
        id: 1,
        text: 'A leaf Node',
        leaf: true
    },{
        id: 2,
        text: 'A folder Node',
        children: [{
            id: 3,
            text: 'A child Node',
            leaf: true
        }]
   }]


A server request is sent, and child nodes are loaded only when a node is expanded. The loading node's id is passed to the server under the parameter name "node" to enable the server to produce the correct child nodes.

To pass extra parameters, an event handler may be attached to the "beforeload" event, and the parameters specified in the TreeLoader's baseParams property:
myTreeLoader.on("beforeload", function(treeLoader, node) {
        this.baseParams.category = node.attributes.category;
    }, this);
This would pass an HTTP parameter called "category" to the server containing the value of the Node's "category" attribute.

Config Options

Config OptionsDefined By
 baseParams : Object
An object containing properties which specify HTTP parameters to be passed to each request for child nodes.
TreeLoader
 clearOnLoad : Boolean
Default to true. Remove previously existing child nodes before loading.
TreeLoader
 directFn : Function
Function to call when executing a request.
TreeLoader
 nodeParameter : String
The name of the parameter sent to the server which contains the identifier of the node. Defaults to 'node'.
TreeLoader
 preloadChildren : Boolean
If set to true, the loader recursively loads "children" attributes when doing the first load on nodes.
TreeLoader
 requestMethod : String
The HTTP request method for loading data (defaults to the value of Ext.Ajax.method).
TreeLoader
 url : String
Equivalent to dataUrl.
TreeLoader

Public Properties

This class has no public properties.

Public Methods

MethodDefined By

Public Events

EventDefined By