title: What is $data in _view.php of blog (demos folder) of yii framework is?
body: <p>I confuse about $data in blog/views/post/_view.php of blog demo of yii framework
  How I get this attribute of $data? Where I can find the define of $data? I find in source but doesn't see any line about <strong>author->username</strong> ,url commentCount?</p>
  
  <pre><code>&lt;div class="post"&gt;
      &lt;div class="title"&gt;
          &lt;?php echo CHtml::link(CHtml::encode($data-&gt;title), $data-&gt;url); ?&gt;
      &lt;/div&gt;
      &lt;div class="author"&gt;
          posted by &lt;?php echo $data-&gt;author-&gt;username . ' on ' . date('F j, Y',$data-&gt;create_time); ?&gt;
      &lt;/div&gt;
      &lt;div class="content"&gt;
          &lt;?php
              $this-&gt;beginWidget('CMarkdown', array('purifyOutput'=&gt;true));
              echo $data-&gt;content;
              $this-&gt;endWidget();
          ?&gt;
      &lt;/div&gt;
      &lt;div class="nav"&gt;
          &lt;b&gt;Tags:&lt;/b&gt;
          &lt;?php echo implode(', ', $data-&gt;tagLinks); ?&gt;
          &lt;br/&gt;
          &lt;?php echo CHtml::link('Permalink', $data-&gt;url); ?&gt; |
          &lt;?php echo CHtml::link("Comments ({$data-&gt;commentCount})",$data-&gt;url.'#comments'); ?&gt; |
          Last updated on &lt;?php echo date('F j, Y',$data-&gt;update_time); ?&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Can you help me to explain or give me some link or some keywork.
  Thank for everything!</p>