title: how to create treeview in yii framework
body: <p>I want to create a tree view which fetching 
  data from Database and after that 
  order it by parent field 
  So table fields are included :</p>
  
  <p>product_category_id</p>
  
  <p>product_category_parent_id</p>
  
  <p>product_category_name</p>
  
  <p>the record that is been mentioned 
  by name " product_category_parent_id"
  is 0 without any root and when it wish have any 
  ID code / number , parent Id should come in this palce
  so structure of the table must be sent to the 
  View :</p>
  
  <pre><code>&lt;ul&gt;&lt;li&gt;&lt;ul&gt;&lt;li&gt;&lt;/li&gt;&lt;/ul&gt;&lt;/li&gt;&lt;/ul&gt;
  </code></pre>