loadModelSlug, Yii - from clean URL tutorial

loadModelSlug.php

public function actionView($slug)
{
    $this->render('view',array(
        'model'=>$this->loadModelSlug($slug),
    ));
}

public function loadModelSlug($slug)
{
    $model = Product::model()->findByAttributes(array('slug'=>$slug));
    if($model===null)
        throw new CHttpException(404,'The requested page does not exist.');
    return $model;
}