Using Unique and Toggle in a TreeView jQuery Hierarchical Navigation System - Restricting the opening of a tree's branches with the unique option (
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As I stated in the previous section, the "TreeView" plug-on provides a parameter called "unique," which can be useful in a number of ways -- for instance, where you wish that users of your web site browse individually categories of a hierarchical menu. But now that you have a vague idea of how this option works, it's time to see how it can be utilized within the context of a concrete example. Take a look at the following one, to grasp more clearly the use of the "unique" argument:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Example on jQuery TreeView (using the unique option)</title>
<link rel="stylesheet" href="jquery.treeview.css" type="text/css" />
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="jquery.treeview.js"></script>
<script>
// build treeview after web page has been loaded
$(document).ready(function(){
$("#menu").treeview({
unique: true
});
});
</script>
</head>
<body>
<ul id="menu">
<li>Link 1
<ul>
<li>Sub link 1</li>
<li>Sub link 2</li>
<li>Sub link 3</li>
<li>Sub link 4</li>
<li>Sub link 5</li>
</ul>
</li>
<li>Link 2
<ul>
<li>Sub link 1</li>
<li>Sub link 2</li>
<li>Sub link 3</li>
<li>Sub link 4</li>
<li>Sub link 5</li>
</ul>
</li>
<li>Link 3
<ul>
<li>Sub link 1</li>
<li>Sub link 2</li>
<li>Sub link 3</li>
<li>Sub link 4</li>
<li>Sub link 5</li>
</ul>
</li>
<li>Link 4
<ul>
<li>Sub link 1</li>
<li>Sub link 2</li>
<li>Sub link 3</li>
<li>Sub link 4</li>
<li>Sub link 5</li>
</ul>
</li>
<li>Link 5
<ul>
<li>Sub link 1</li>
<li>Sub link 2</li>
<li>Sub link 3</li>
<li>Sub link 4</li>
<li>Sub link 5</li>
</ul>
</li>
</ul>
</body>
</html>
From the previous code sample, it's clear to see how simple it is to restrict the behavior of a targeted tree to permit only one branch to be expanded at a time. Naturally, the best way to understand how the "unique" argument does its business is for you to try out this example on your own browser, so I encourage you to do that as soon as you can. You'll be surprised to see how smoothly it functions.
Since at this stage you hopefully grasped the logic that stands behind using the "unique" option, it's time to continue exploring other capabilities offered by the "TreeView" plug-in. Therefore, in the last section of this tutorial I'm going to discuss the use of the "toggle" parameter, which can be used for triggering callback functions when branches of a tree are expanded and collapsed.
This topic will be discussed in detail in the following segment. Thus, to learn more about it, click on the link below and read the next few lines.
