-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"></div></li><li><code>scope</code> : (Object)<div class="sub-desc"></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"> </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>( <code>String eventName</code>, <code>Function handler</code>, <span title="Optional" class="optional">[<code>Object scope</code>]</span>, <span title="Optional" class="optional">[<code>Object options</code>]</span> )\r
+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 \r
+function is passed the TreeNode which was requested to be loaded.</div></li><li><code>scope</code> : (Object)<div class="sub-desc">The cope (<code>this</code> reference) in which the callback is executed.\r
+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"> </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>( <code>String eventName</code>, <code>Function handler</code>, <span title="Optional" class="optional">[<code>Object scope</code>]</span>, <span title="Optional" class="optional">[<code>Object options</code>]</span> )\r