title: What is the purpose of parent::beforeSave in Yii Framework?
body: <pre><code>protected  function  beforeSave()
  {
      if ( parent :: beforeSave())
      {
          if ( $this -&gt; isNewRecord )
               $this -&gt; create_time =time () ;
          return true ;
      }
      else
          return false;
  }
  </code></pre>
  
  <p>This is code from the demo blog within Yii framework,I do not know the purpose of parent :: beforeSave(),why we should use it ?I am new to PHP thanks !</p>