ASP.NET 2.0 Treeview Checkboxes - Check All - Javascript

<asp:TreeView ID="TreeView1" Runat="server" DataSourceID="XmlDataSource1" onclick="client_OnTreeNodeChecked();" ShowCheckBoxes="all">

<DataBindings>

<asp:TreeNodeBinding DataMember="Category" ValueField="ID" TextField="Name"></asp:TreeNodeBinding>

<asp:TreeNodeBinding DataMember="Description" ValueField="Value" TextField="Value"></asp:TreeNodeBinding>

</DataBindings>

</asp:TreeView>

In the above TreeView declaration Code, you can find the property onclick="client_OnTreeNodeChecked();" event which actually is the JavaScript function which would accomplish this task.

The Javascript Code snippet is as follows:-

<script language="javascript" type="text/javascript">
function client_OnTreeNodeChecked()
{
var obj = window.event.srcElement;
var treeNodeFound = false;
var checkedState;
if (obj.tagName == "INPUT" && obj.type == "checkbox") {
var treeNode = obj;
checkedState = treeNode.checked;
do
{
obj = obj.parentElement;
} while (obj.tagName != "TABLE")
var parentTreeLevel = obj.rows[0].cells.length;
var parentTreeNode = obj.rows[0].cells[0];
var tables = obj.parentElement.getElementsByTagName("TABLE");
var numTables = tables.length
if (numTables >= 1)
{
for (i=0; i < numTables; i++)
{
if (tables[i] == obj)
{
treeNodeFound = true;
i++;
if (i == numTables)
{
return;
}
}
if (treeNodeFound == true)
{
var childTreeLevel = tables[i].rows[0].cells.length;
if (childTreeLevel > parentTreeLevel)
{
var cell = tables[i].rows[0].cells[childTreeLevel - 1];
var inputs = cell.getElementsByTagName("INPUT");
inputs[0].checked = checkedState;
}
else
{
return;
}
}
}
}
}
}
</script>