docs/output/Ext.tree.TreeLoader.html

   1 <div class="body-wrap" xmlns:ext="http://www.extjs.com"><div class="top-tools"><a class="inner-link" href="#Ext.tree.TreeLoader-props"><img src="resources/images/default/s.gif" class="item-icon icon-prop">Properties</a>&#13;<a class="inner-link" href="#Ext.tree.TreeLoader-methods"><img src="resources/images/default/s.gif" class="item-icon icon-method">Methods</a>&#13;<a class="inner-link" href="#Ext.tree.TreeLoader-events"><img src="resources/images/default/s.gif" class="item-icon icon-event">Events</a>&#13;<a class="inner-link" href="#Ext.tree.TreeLoader-configs"><img src="resources/images/default/s.gif" class="item-icon icon-config">Config Options</a>&#13;<a class="bookmark" href="../docs/?class=Ext.tree.TreeLoader"><img src="resources/images/default/s.gif" class="item-icon icon-fav">Direct Link</a>&#13;</div><div class="inheritance res-block"><pre class="res-block-inner"><a href="output/Ext.util.Observable.html" ext:member="" ext:cls="Ext.util.Observable">Observable</a>
   2   <img src="resources/elbow-end.gif">TreeLoader</pre></div><h1>Class <a href="source/TreeLoader.html#cls-Ext.tree.TreeLoader">Ext.tree.TreeLoader</a></h1><table cellspacing="0"><tr><td class="label">Package:</td><td class="hd-info">Ext.tree</td></tr><tr><td class="label">Defined In:</td><td class="hd-info"><a href="source/TreeLoader.html#cls-Ext.tree.TreeLoader">TreeLoader.js</a></td></tr><tr><td class="label">Class:</td><td class="hd-info"><a href="source/TreeLoader.html#cls-Ext.tree.TreeLoader">TreeLoader</a></td></tr><tr><td class="label">Extends:</td><td class="hd-info"><a href="output/Ext.util.Observable.html" ext:cls="Ext.util.Observable" ext:member="">Observable</a></td></tr></table><div class="description">A TreeLoader provides for lazy loading of an <a href="output/Ext.tree.TreeNode.html" ext:cls="Ext.tree.TreeNode">Ext.tree.TreeNode</a>'s child
   3 nodes from a specified URL. The response must be a JavaScript Array definition
   4 whose elements are node definition objects. e.g.:
   5 <pre><code>[{
   6         id: 1,
   7         text: <em>'A leaf Node'</em>,
   8         leaf: true
   9     },{
  10         id: 2,
  11         text: <em>'A folder Node'</em>,
  12         children: [{
  13             id: 3,
  14             text: <em>'A child Node'</em>,
  15             leaf: true
  16         }]
  17    }]</code></pre>
  18 <br><br>
  19 A server request is sent, and child nodes are loaded only when a node is expanded.
  20 The loading node's id is passed to the server under the parameter name "node" to
  21 enable the server to produce the correct child nodes.
  22 <br><br>
  23 To pass extra parameters, an event handler may be attached to the "beforeload"
  24 event, and the parameters specified in the TreeLoader's baseParams property:
  25 <pre><code>myTreeLoader.on(<em>"beforeload"</em>, <b>function</b>(treeLoader, node) {
  26         this.baseParams.category = node.attributes.category;
  27     }, this);</code></pre>
  28 This would pass an HTTP parameter called "category" to the server containing
  29 the value of the Node's "category" attribute.</div><div class="hr"></div><a id="Ext.tree.TreeLoader-configs"></a><h2>Config Options</h2><table cellspacing="0" class="member-table"><tbody><tr><th colspan="2" class="sig-header">Config Options</th><th class="msource-header">Defined By</th></tr><tr class="config-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-baseAttrs"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-baseAttrs">baseAttrs</a></b> : Object<div class="mdesc"><div class="short">An object containing attributes to be added to all nodes
  30 created by this loader. If the attributes sent by the server...</div><div class="long">An object containing attributes to be added to all nodes
  31 created by this loader. If the attributes sent by the server have an attribute in this object,
  32 they take priority.</div></div></td><td class="msource">TreeLoader</td></tr><tr class="config-row  "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-baseParams"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-baseParams">baseParams</a></b> : Object<div class="mdesc">An object containing properties which
  33 specify HTTP parameters to be passed to each request for child nodes.</div></td><td class="msource">TreeLoader</td></tr><tr class="config-row  "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-clearOnLoad"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-clearOnLoad">clearOnLoad</a></b> : Boolean<div class="mdesc">Default to true. Remove previously existing
  34 child nodes before loading.</div></td><td class="msource">TreeLoader</td></tr><tr class="config-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-dataUrl"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-dataUrl">dataUrl</a></b> : String<div class="mdesc"><div class="short">The URL from which to request a Json string which
  35 specifies an array of node definition objects representing the chil...</div><div class="long">The URL from which to request a Json string which
  36 specifies an array of node definition objects representing the child nodes
  37 to be loaded.</div></div></td><td class="msource">TreeLoader</td></tr><tr class="config-row  "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-directFn"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-directFn">directFn</a></b> : Function<div class="mdesc">Function to call when executing a request.</div></td><td class="msource">TreeLoader</td></tr><tr class="config-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-listeners"></a><b><a href="source/Observable.html#cfg-Ext.util.Observable-listeners">listeners</a></b> : Object<div class="mdesc"><div class="short">A config object containing one or more event handlers to be added to this
  38 object during initialization.  This should ...</div><div class="long"><p>A config object containing one or more event handlers to be added to this
  39 object during initialization.  This should be a valid listeners config object as specified in the
  40 <a href="output/Ext.util.Observable.html#Ext.util.Observable-addListener" ext:member="addListener" ext:cls="Ext.util.Observable">addListener</a> example for attaching multiple handlers at once.</p>
  41 <br><p><b><u>DOM events from ExtJs <a href="output/Ext.Component.html" ext:cls="Ext.Component">Components</a></u></b></p>
  42 <br><p>While <i>some</i> ExtJs Component classes export selected DOM events (e.g. "click", "mouseover" etc), this
  43 is usually only done when extra value can be added. For example the <a href="output/Ext.DataView.html" ext:cls="Ext.DataView">DataView</a>'s
  44 <b><code><a href="output/Ext.DataView.html#Ext.DataView-click" ext:member="click" ext:cls="Ext.DataView">click</a></code></b> event passing the node clicked on. To access DOM
  45 events directly from a Component's HTMLElement, listeners must be added to the <i><a href="output/Ext.Component.html#Ext.Component-getEl" ext:member="getEl" ext:cls="Ext.Component">Element</a></i> after the Component
  46 has been rendered. A plugin can simplify this step:<pre><code><i>// Plugin is configured <b>with</b> a listeners config object.</i>
  47 <i>// The Component is appended to the argument list of all handler functions.</i>
  48 Ext.DomObserver = Ext.extend(Object, {
  49     constructor: <b>function</b>(config) {
  50         this.listeners = config.listeners ? config.listeners : config;
  51     },
  52
  53     <i>// Component passes itself into plugin&#39;s init method</i>
  54     init: <b>function</b>(c) {
  55         <b>var</b> p, l = this.listeners;
  56         <b>for</b> (p <b>in</b> l) {
  57             <b>if</b> (Ext.isFunction(l[p])) {
  58                 l[p] = this.createHandler(l[p], c);
  59             } <b>else</b> {
  60                 l[p].fn = this.createHandler(l[p].fn, c);
  61             }
  62         }
  63
  64         <i>// Add the listeners to the Element immediately following the render call</i>
  65         c.render = c.render.<a href="output/Function.html#Function-createSequence" ext:member="createSequence" ext:cls="Function">createSequence</a>(<b>function</b>() {
  66             <b>var</b> e = c.getEl();
  67             <b>if</b> (e) {
  68                 e.on(l);
  69             }
  70         });
  71     },
  72
  73     createHandler: <b>function</b>(fn, c) {
  74         <b>return</b> <b>function</b>(e) {
  75             fn.call(this, e, c);
  76         };
  77     }
  78 });
  79
  80 <b>var</b> combo = <b>new</b> Ext.form.ComboBox({
  81
  82     <i>// Collapse combo when its element is clicked on</i>
  83     plugins: [ <b>new</b> Ext.DomObserver({
  84         click: <b>function</b>(evt, comp) {
  85             comp.collapse();
  86         }
  87     })],
  88     store: myStore,
  89     typeAhead: true,
  90     mode: <em>'local'</em>,
  91     triggerAction: <em>'all'</em>
  92 });</code></pre></p></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#listeners" ext:member="#listeners" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="config-row  "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-nodeParameter"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-nodeParameter">nodeParameter</a></b> : String<div class="mdesc">The name of the parameter sent to the server which contains
  93 the identifier of the node. Defaults to <tt>'node'</tt>.</div></td><td class="msource">TreeLoader</td></tr><tr class="config-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-paramOrder"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-paramOrder">paramOrder</a></b> : Array/String<div class="mdesc"><div class="short">Defaults to undefined. Only used when using directFn.
  94 Specifies the params in the order in which they must be passed ...</div><div class="long">Defaults to <tt>undefined</tt>. Only used when using directFn.
  95 Specifies the params in the order in which they must be passed to the server-side Direct method
  96 as either (1) an Array of String values, or (2) a String of params delimited by either whitespace,
  97 comma, or pipe. For example,
  98 any of the following would be acceptable:<pre><code>nodeParameter: <em>'node'</em>,
  99 paramOrder: [<em>'param1'</em>,<em>'param2'</em>,<em>'param3'</em>]
 100 paramOrder: <em>'node param1 param2 param3'</em>
 101 paramOrder: <em>'param1,node,param2,param3'</em>
 102 paramOrder: <em>'param1|param2|param|node'</em></code></pre></div></div></td><td class="msource">TreeLoader</td></tr><tr class="config-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-paramsAsHash"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-paramsAsHash">paramsAsHash</a></b> : Boolean<div class="mdesc"><div class="short">Only used when using directFn.
 103 Send parameters as a collection of named arguments (defaults to false). Providing a
 104 pa...</div><div class="long">Only used when using directFn.
 105 Send parameters as a collection of named arguments (defaults to <tt>false</tt>). Providing a
 106 <tt><a href="output/Ext.tree.TreeLoader.html#Ext.tree.TreeLoader-paramOrder" ext:member="paramOrder" ext:cls="Ext.tree.TreeLoader">paramOrder</a></tt> nullifies this configuration.</div></div></td><td class="msource">TreeLoader</td></tr><tr class="config-row  "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-preloadChildren"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-preloadChildren">preloadChildren</a></b> : Boolean<div class="mdesc">If set to true, the loader recursively loads "children" attributes when doing the first load on nodes.</div></td><td class="msource">TreeLoader</td></tr><tr class="config-row  "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-requestMethod"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-requestMethod">requestMethod</a></b> : String<div class="mdesc">The HTTP request method for loading data (defaults to the value of <a href="output/Ext.Ajax.html#Ext.Ajax-method" ext:member="method" ext:cls="Ext.Ajax">Ext.Ajax.method</a>).</div></td><td class="msource">TreeLoader</td></tr><tr class="config-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-uiProviders"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-uiProviders">uiProviders</a></b> : Object<div class="mdesc"><div class="short">An object containing properties which
 107 specify custom Ext.tree.TreeNodeUI implementations. If the optional
 108 uiProvider ...</div><div class="long">An object containing properties which
 109 specify custom <a href="output/Ext.tree.TreeNodeUI.html" ext:cls="Ext.tree.TreeNodeUI">Ext.tree.TreeNodeUI</a> implementations. If the optional
 110 <i>uiProvider</i> attribute of a returned child node is a string rather
 111 than a reference to a TreeNodeUI implementation, then that string value
 112 is used as a property name in the uiProviders object.</div></div></td><td class="msource">TreeLoader</td></tr><tr class="config-row  "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-url"></a><b><a href="source/TreeLoader.html#cfg-Ext.tree.TreeLoader-url">url</a></b> : String<div class="mdesc">Equivalent to <a href="output/Ext.tree.TreeLoader.html#Ext.tree.TreeLoader-dataUrl" ext:member="dataUrl" ext:cls="Ext.tree.TreeLoader">dataUrl</a>.</div></td><td class="msource">TreeLoader</td></tr></tbody></table><a id="Ext.tree.TreeLoader-props"></a><h2>Public Properties</h2><div class="no-members">This class has no public properties.</div><a id="Ext.tree.TreeLoader-methods"></a><h2>Public Methods</h2><table cellspacing="0" class="member-table"><tbody><tr><th colspan="2" class="sig-header">Method</th><th class="msource-header">Defined By</th></tr><tr class="method-row expandable"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-TreeLoader"></a><b><a href="source/TreeLoader.html#cls-Ext.tree.TreeLoader">TreeLoader</a></b>(&nbsp;<code>Object&nbsp;config</code>&nbsp;)
 113     <div class="mdesc"><div class="short">Creates a new Treeloader.</div><div class="long">Creates a new Treeloader.<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>config</code> : Object<div class="sub-desc">A config object containing config properties.</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource">TreeLoader</td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-addEvents"></a><b><a href="source/Observable.html#method-Ext.util.Observable-addEvents">addEvents</a></b>(&nbsp;<code>Object|String&nbsp;o</code>,&nbsp;<code>string&nbsp;Optional.</code>&nbsp;)
 114     :
 115                                         void<div class="mdesc"><div class="short">Adds the specified events to the list of events which this Observable may fire.</div><div class="long">Adds the specified events to the list of events which this Observable may fire.<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>o</code> : Object|String<div class="sub-desc">Either an object with event names as properties with a value of <code>true</code>
 116 or the first event name string if multiple event names are being passed as separate parameters.</div></li><li><code>Optional.</code> : string<div class="sub-desc">Event name if multiple event names are being passed as separate parameters.
 117 Usage:<pre><code>this.addEvents(<em>'storeloaded'</em>, <em>'storecleared'</em>);</code></pre></div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#addEvents" ext:member="#addEvents" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-addListener"></a><b><a href="source/Observable.html#method-Ext.util.Observable-addListener">addListener</a></b>(&nbsp;<code>String&nbsp;eventName</code>,&nbsp;<code>Function&nbsp;handler</code>,&nbsp;<span title="Optional" class="optional">[<code>Object&nbsp;scope</code>]</span>,&nbsp;<span title="Optional" class="optional">[<code>Object&nbsp;options</code>]</span>&nbsp;)
 118     :
 119                                         void<div class="mdesc"><div class="short">Appends an event handler to this object.</div><div class="long">Appends an event handler to this object.<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>eventName</code> : String<div class="sub-desc">The name of the event to listen for.</div></li><li><code>handler</code> : Function<div class="sub-desc">The method the event invokes.</div></li><li><code>scope</code> : Object<div class="sub-desc">(optional) The scope (<code><b>this</b></code> reference) in which the handler function is executed.
 120 <b>If omitted, defaults to the object which fired the event.</b></div></li><li><code>options</code> : Object<div class="sub-desc">(optional) An object containing handler configuration.
 121 properties. This may contain any of the following properties:<ul>
 122 <li><b>scope</b> : Object<div class="sub-desc">The scope (<code><b>this</b></code> reference) in which the handler function is executed.
 123 <b>If omitted, defaults to the object which fired the event.</b></div></li>
 124 <li><b>delay</b> : Number<div class="sub-desc">The number of milliseconds to delay the invocation of the handler after the event fires.</div></li>
 125 <li><b>single</b> : Boolean<div class="sub-desc">True to add a handler to handle just the next firing of the event, and then remove itself.</div></li>
 126 <li><b>buffer</b> : Number<div class="sub-desc">Causes the handler to be scheduled to run in an <a href="output/Ext.util.DelayedTask.html" ext:cls="Ext.util.DelayedTask">Ext.util.DelayedTask</a> delayed
 127 by the specified number of milliseconds. If the event fires again within that time, the original
 128 handler is <em>not</em> invoked, but the new handler is scheduled in its place.</div></li>
 129 <li><b>target</b> : Observable<div class="sub-desc">Only call the handler if the event was fired on the target Observable, <i>not</i>
 130 if the event was bubbled up from a child Observable.</div></li>
 131 </ul><br>
 132 <p>
 133 <b>Combining Options</b><br>
 134 Using the options argument, it is possible to combine different types of listeners:<br>
 135 <br>
 136 A delayed, one-time listener.
 137 <pre><code>myDataView.on(<em>'click'</em>, this.onClick, this, {
 138 single: true,
 139 delay: 100
 140 });</code></pre>
 141 <p>
 142 <b>Attaching multiple handlers in 1 call</b><br>
 143 The method also allows for a single argument to be passed which is a config object containing properties
 144 which specify multiple handlers.
 145 <p>
 146 <pre><code>myGridPanel.on({
 147 <em>'click'</em> : {
 148     fn: this.onClick,
 149     scope: this,
 150     delay: 100
 151 },
 152 <em>'mouseover'</em> : {
 153     fn: this.onMouseOver,
 154     scope: this
 155 },
 156 <em>'mouseout'</em> : {
 157     fn: this.onMouseOut,
 158     scope: this
 159 }
 160 });</code></pre>
 161 <p>
 162 Or a shorthand syntax:<br>
 163 <pre><code>myGridPanel.on({
 164 <em>'click'</em> : this.onClick,
 165 <em>'mouseover'</em> : this.onMouseOver,
 166 <em>'mouseout'</em> : this.onMouseOut,
 167  scope: this
 168 });</code></pre></div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#addListener" ext:member="#addListener" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-createNode"></a><b><a href="source/TreeLoader.html#method-Ext.tree.TreeLoader-createNode">createNode</a></b>(&nbsp;<code>attr&nbsp;{Object}</code>&nbsp;)
 169     :
 170                                         void<div class="mdesc"><div class="short">Override this function for custom TreeNode node implementation, or to
 171 modify the attributes at creation time.
 172 Example...</div><div class="long"><p>Override this function for custom TreeNode node implementation, or to
 173 modify the attributes at creation time.</p>
 174 Example:<pre><code><b>new</b> Ext.tree.TreePanel({
 175     ...
 176     loader: <b>new</b> Ext.tree.TreeLoader({
 177         url: <em>'dataUrl'</em>,
 178         createNode: <b>function</b>(attr) {
 179 <i>//          Allow consolidation consignments to have</i>
 180 <i>//          consignments dropped into them.</i>
 181             <b>if</b> (attr.isConsolidation) {
 182                 attr.iconCls = <em>'x-consol'</em>,
 183                 attr.allowDrop = true;
 184             }
 185             <b>return</b> Ext.tree.TreeLoader.prototype.createNode.call(this, attr);
 186         }
 187     }),
 188     ...
 189 });</code></pre><div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>{Object}</code> : attr<div class="sub-desc">The attributes from which to create the new node.</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource">TreeLoader</td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-enableBubble"></a><b><a href="source/Observable-more.html#method-Ext.util.Observable-enableBubble">enableBubble</a></b>(&nbsp;<code>String/Array&nbsp;events</code>&nbsp;)
 190     :
 191                                         void<div class="mdesc"><div class="short">Enables events fired by this Observable to bubble up an owner hierarchy by calling
 192 this.getBubbleTarget() if present....</div><div class="long"><p>Enables events fired by this Observable to bubble up an owner hierarchy by calling
 193 <code>this.getBubbleTarget()</code> if present. There is no implementation in the Observable base class.</p>
 194 <p>This is commonly used by Ext.Components to bubble events to owner Containers. See <a href="output/Ext.Component.getBubbleTarget.html" ext:cls="Ext.Component.getBubbleTarget">Ext.Component.getBubbleTarget</a>. The default
 195 implementation in Ext.Component returns the Component's immediate owner. But if a known target is required, this can be overridden to
 196 access the required target more quickly.</p>
 197 <p>Example:</p><pre><code>Ext.override(Ext.form.Field, {
 198     <i>//  Add functionality to Field&#39;s initComponent to enable the change event to bubble</i>
 199     initComponent : Ext.form.Field.prototype.initComponent.createSequence(<b>function</b>() {
 200         this.enableBubble(<em>'change'</em>);
 201     }),
 202
 203     <i>//  We know that we want Field&#39;s events to bubble directly to the FormPanel.</i>
 204     getBubbleTarget : <b>function</b>() {
 205         <b>if</b> (!this.formPanel) {
 206             this.formPanel = this.findParentByType(<em>'form'</em>);
 207         }
 208         <b>return</b> this.formPanel;
 209     }
 210 });
 211
 212 <b>var</b> myForm = <b>new</b> Ext.formPanel({
 213     title: <em>'User Details'</em>,
 214     items: [{
 215         ...
 216     }],
 217     listeners: {
 218         change: <b>function</b>() {
 219             <i>// Title goes red <b>if</b> form has been modified.</i>
 220             myForm.header.setStyle(<em>'color'</em>, <em>'red'</em>);
 221         }
 222     }
 223 });</code></pre><div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>events</code> : String/Array<div class="sub-desc">The event name to bubble, or an Array of event names.</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#enableBubble" ext:member="#enableBubble" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-fireEvent"></a><b><a href="source/Observable.html#method-Ext.util.Observable-fireEvent">fireEvent</a></b>(&nbsp;<code>String&nbsp;eventName</code>,&nbsp;<code>Object...&nbsp;args</code>&nbsp;)
 224     :
 225                                         Boolean<div class="mdesc"><div class="short">Fires the specified event with the passed parameters (minus the event name).
 226 An event may be set to bubble up an Obse...</div><div class="long"><p>Fires the specified event with the passed parameters (minus the event name).</p>
 227 <p>An event may be set to bubble up an Observable parent hierarchy (See <a href="output/Ext.Component.html#Ext.Component-getBubbleTarget" ext:member="getBubbleTarget" ext:cls="Ext.Component">Ext.Component.getBubbleTarget</a>)
 228 by calling <a href="output/Ext.util.Observable.html#Ext.util.Observable-enableBubble" ext:member="enableBubble" ext:cls="Ext.util.Observable">enableBubble</a>.</p><div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>eventName</code> : String<div class="sub-desc">The name of the event to fire.</div></li><li><code>args</code> : Object...<div class="sub-desc">Variable number of parameters are passed to handlers.</div></li></ul><strong>Returns:</strong><ul><li><code>Boolean</code><div class="sub-desc">returns false if any of the handlers return false otherwise it returns true.</div></li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#fireEvent" ext:member="#fireEvent" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-hasListener"></a><b><a href="source/Observable.html#method-Ext.util.Observable-hasListener">hasListener</a></b>(&nbsp;<code>String&nbsp;eventName</code>&nbsp;)
 229     :
 230                                         Boolean<div class="mdesc"><div class="short">Checks to see if this object has any listeners for a specified event</div><div class="long">Checks to see if this object has any listeners for a specified event<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>eventName</code> : String<div class="sub-desc">The name of the event to check for</div></li></ul><strong>Returns:</strong><ul><li><code>Boolean</code><div class="sub-desc">True if the event is being listened for, else false</div></li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#hasListener" ext:member="#hasListener" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-load"></a><b><a href="source/TreeLoader.html#method-Ext.tree.TreeLoader-load">load</a></b>(&nbsp;<code>Ext.tree.TreeNode&nbsp;node</code>,&nbsp;<code>Function&nbsp;callback</code>,&nbsp;<code>Object&nbsp;scope</code>&nbsp;)
 231     :
 232                                         void<div class="mdesc"><div class="short">Load an Ext.tree.TreeNode from the URL specified in the constructor.
 233 This is called automatically when a node is expa...</div><div class="long">Load an <a href="output/Ext.tree.TreeNode.html" ext:cls="Ext.tree.TreeNode">Ext.tree.TreeNode</a> from the URL specified in the constructor.
 234 This is called automatically when a node is expanded, but may be used to reload
 235 a node (or append new children if the <a href="output/Ext.tree.TreeLoader.html#Ext.tree.TreeLoader-clearOnLoad" ext:member="clearOnLoad" ext:cls="Ext.tree.TreeLoader">clearOnLoad</a> option is false.)<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>node</code> : Ext.tree.TreeNode<div class="sub-desc"></div></li><li><code>callback</code> : Function<div class="sub-desc">Function to call after the node has been loaded. The
 236 function is passed the TreeNode which was requested to be loaded.</div></li><li><code>scope</code> : Object<div class="sub-desc">The scope (<code>this</code> reference) in which the callback is executed.
 237 defaults to the loaded TreeNode.</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource">TreeLoader</td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-on"></a><b><a href="source/Observable.html#method-Ext.util.Observable-on">on</a></b>(&nbsp;<code>String&nbsp;eventName</code>,&nbsp;<code>Function&nbsp;handler</code>,&nbsp;<span title="Optional" class="optional">[<code>Object&nbsp;scope</code>]</span>,&nbsp;<span title="Optional" class="optional">[<code>Object&nbsp;options</code>]</span>&nbsp;)
 238     :
 239                                         void<div class="mdesc"><div class="short">Appends an event handler to this object (shorthand for addListener.)</div><div class="long">Appends an event handler to this object (shorthand for <a href="output/Ext.util.Observable.html#Ext.util.Observable-addListener" ext:member="addListener" ext:cls="Ext.util.Observable">addListener</a>.)<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>eventName</code> : String<div class="sub-desc">The type of event to listen for</div></li><li><code>handler</code> : Function<div class="sub-desc">The method the event invokes</div></li><li><code>scope</code> : Object<div class="sub-desc">(optional) The scope (<code><b>this</b></code> reference) in which the handler function is executed.
 240 <b>If omitted, defaults to the object which fired the event.</b></div></li><li><code>options</code> : Object<div class="sub-desc">(optional) An object containing handler configuration.</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#on" ext:member="#on" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-purgeListeners"></a><b><a href="source/Observable.html#method-Ext.util.Observable-purgeListeners">purgeListeners</a></b>()
 241     :
 242                                         void<div class="mdesc"><div class="short">Removes all listeners for this object</div><div class="long">Removes all listeners for this object<div class="mdetail-params"><strong>Parameters:</strong><ul><li>None.</li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#purgeListeners" ext:member="#purgeListeners" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-relayEvents"></a><b><a href="source/Observable-more.html#method-Ext.util.Observable-relayEvents">relayEvents</a></b>(&nbsp;<code>Object&nbsp;o</code>,&nbsp;<code>Array&nbsp;events</code>&nbsp;)
 243     :
 244                                         void<div class="mdesc"><div class="short">Relays selected events from the specified Observable as if the events were fired by this.</div><div class="long">Relays selected events from the specified Observable as if the events were fired by <tt><b>this</b></tt>.<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>o</code> : Object<div class="sub-desc">The Observable whose events this object is to relay.</div></li><li><code>events</code> : Array<div class="sub-desc">Array of event names to relay.</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#relayEvents" ext:member="#relayEvents" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-removeListener"></a><b><a href="source/Observable.html#method-Ext.util.Observable-removeListener">removeListener</a></b>(&nbsp;<code>String&nbsp;eventName</code>,&nbsp;<code>Function&nbsp;handler</code>,&nbsp;<span title="Optional" class="optional">[<code>Object&nbsp;scope</code>]</span>&nbsp;)
 245     :
 246                                         void<div class="mdesc"><div class="short">Removes an event handler.</div><div class="long">Removes an event handler.<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>eventName</code> : String<div class="sub-desc">The type of event the handler was associated with.</div></li><li><code>handler</code> : Function<div class="sub-desc">The handler to remove. <b>This must be a reference to the function passed into the <a href="output/Ext.util.Observable.html#Ext.util.Observable-addListener" ext:member="addListener" ext:cls="Ext.util.Observable">addListener</a> call.</b></div></li><li><code>scope</code> : Object<div class="sub-desc">(optional) The scope originally specified for the handler.</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#removeListener" ext:member="#removeListener" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-resumeEvents"></a><b><a href="source/Observable.html#method-Ext.util.Observable-resumeEvents">resumeEvents</a></b>()
 247     :
 248                                         void<div class="mdesc"><div class="short">Resume firing events. (see suspendEvents)
 249 If events were suspended using the queueSuspended parameter, then all
 250 event...</div><div class="long">Resume firing events. (see <a href="output/Ext.util.Observable.html#Ext.util.Observable-suspendEvents" ext:member="suspendEvents" ext:cls="Ext.util.Observable">suspendEvents</a>)
 251 If events were suspended using the <tt><b>queueSuspended</b></tt> parameter, then all
 252 events fired during event suspension will be sent to any listeners now.<div class="mdetail-params"><strong>Parameters:</strong><ul><li>None.</li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#resumeEvents" ext:member="#resumeEvents" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-suspendEvents"></a><b><a href="source/Observable.html#method-Ext.util.Observable-suspendEvents">suspendEvents</a></b>(&nbsp;<code>Boolean&nbsp;queueSuspended</code>&nbsp;)
 253     :
 254                                         void<div class="mdesc"><div class="short">Suspend the firing of all events. (see resumeEvents)</div><div class="long">Suspend the firing of all events. (see <a href="output/Ext.util.Observable.html#Ext.util.Observable-resumeEvents" ext:member="resumeEvents" ext:cls="Ext.util.Observable">resumeEvents</a>)<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>queueSuspended</code> : Boolean<div class="sub-desc">Pass as true to queue up suspended events to be fired
 255 after the <a href="output/Ext.util.Observable.html#Ext.util.Observable-resumeEvents" ext:member="resumeEvents" ext:cls="Ext.util.Observable">resumeEvents</a> call instead of discarding all suspended events;</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#suspendEvents" ext:member="#suspendEvents" ext:cls="Ext.util.Observable">Observable</a></td></tr><tr class="method-row expandable inherited"><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.util.Observable-un"></a><b><a href="source/Observable.html#method-Ext.util.Observable-un">un</a></b>(&nbsp;<code>String&nbsp;eventName</code>,&nbsp;<code>Function&nbsp;handler</code>,&nbsp;<span title="Optional" class="optional">[<code>Object&nbsp;scope</code>]</span>&nbsp;)
 256     :
 257                                         void<div class="mdesc"><div class="short">Removes an event handler (shorthand for removeListener.)</div><div class="long">Removes an event handler (shorthand for <a href="output/Ext.util.Observable.html#Ext.util.Observable-removeListener" ext:member="removeListener" ext:cls="Ext.util.Observable">removeListener</a>.)<div class="mdetail-params"><strong>Parameters:</strong><ul><li><code>eventName</code> : String<div class="sub-desc">The type of event the handler was associated with.</div></li><li><code>handler</code> : Function<div class="sub-desc">The handler to remove. <b>This must be a reference to the function passed into the <a href="output/Ext.util.Observable.html#Ext.util.Observable-addListener" ext:member="addListener" ext:cls="Ext.util.Observable">addListener</a> call.</b></div></li><li><code>scope</code> : Object<div class="sub-desc">(optional) The scope originally specified for the handler.</div></li></ul><strong>Returns:</strong><ul><li>void</li></ul></div></div></div></td><td class="msource"><a href="output/Ext.util.Observable.html#un" ext:member="#un" ext:cls="Ext.util.Observable">Observable</a></td></tr></tbody></table><a id="Ext.tree.TreeLoader-events"></a><h2>Public Events</h2><table cellspacing="0" class="member-table"><tbody><tr><th colspan="2" class="sig-header">Event</th><th class="msource-header">Defined By</th></tr><tr class="method-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-beforeload"></a><b><a href="source/TreeLoader.html#event-Ext.tree.TreeLoader-beforeload">beforeload</a></b> :
 258                                       (&nbsp;<code>Object&nbsp;This</code>,&nbsp;<code>Object&nbsp;node</code>,&nbsp;<code>Object&nbsp;callback</code>&nbsp;)
 259     <div class="mdesc"><div class="short">Fires before a network request is made to retrieve the Json text which specifies a node's children.</div><div class="long">Fires before a network request is made to retrieve the Json text which specifies a node's children.<div class="mdetail-params"><strong style="font-weight: normal;">Listeners will be called with the following arguments:</strong><ul><li><code>This</code> : Object<div class="sub-desc">TreeLoader object.</div></li><li><code>node</code> : Object<div class="sub-desc">The <a href="output/Ext.tree.TreeNode.html" ext:cls="Ext.tree.TreeNode">Ext.tree.TreeNode</a> object being loaded.</div></li><li><code>callback</code> : Object<div class="sub-desc">The callback function specified in the <a href="output/Ext.tree.TreeLoader.html#Ext.tree.TreeLoader-load" ext:member="load" ext:cls="Ext.tree.TreeLoader">load</a> call.</div></li></ul></div></div></div></td><td class="msource">TreeLoader</td></tr><tr class="method-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-load"></a><b><a href="source/TreeLoader.html#event-Ext.tree.TreeLoader-load">load</a></b> :
 260                                       (&nbsp;<code>Object&nbsp;This</code>,&nbsp;<code>Object&nbsp;node</code>,&nbsp;<code>Object&nbsp;response</code>&nbsp;)
 261     <div class="mdesc"><div class="short">Fires when the node has been successfuly loaded.</div><div class="long">Fires when the node has been successfuly loaded.<div class="mdetail-params"><strong style="font-weight: normal;">Listeners will be called with the following arguments:</strong><ul><li><code>This</code> : Object<div class="sub-desc">TreeLoader object.</div></li><li><code>node</code> : Object<div class="sub-desc">The <a href="output/Ext.tree.TreeNode.html" ext:cls="Ext.tree.TreeNode">Ext.tree.TreeNode</a> object being loaded.</div></li><li><code>response</code> : Object<div class="sub-desc">The response object containing the data from the server.</div></li></ul></div></div></div></td><td class="msource">TreeLoader</td></tr><tr class="method-row expandable "><td class="micon"><a href="#expand" class="exi">&nbsp;</a></td><td class="sig"><a id="Ext.tree.TreeLoader-loadexception"></a><b><a href="source/TreeLoader.html#event-Ext.tree.TreeLoader-loadexception">loadexception</a></b> :
 262                                       (&nbsp;<code>Object&nbsp;This</code>,&nbsp;<code>Object&nbsp;node</code>,&nbsp;<code>Object&nbsp;response</code>&nbsp;)
 263     <div class="mdesc"><div class="short">Fires if the network request failed.</div><div class="long">Fires if the network request failed.<div class="mdetail-params"><strong style="font-weight: normal;">Listeners will be called with the following arguments:</strong><ul><li><code>This</code> : Object<div class="sub-desc">TreeLoader object.</div></li><li><code>node</code> : Object<div class="sub-desc">The <a href="output/Ext.tree.TreeNode.html" ext:cls="Ext.tree.TreeNode">Ext.tree.TreeNode</a> object being loaded.</div></li><li><code>response</code> : Object<div class="sub-desc">The response object containing the data from the server.</div></li></ul></div></div></div></td><td class="msource">TreeLoader</td></tr></tbody></table></div>