PHP notice

Trying to get property 'child_nodes' of non-object

/home/quanghuysk/public_html/protected/controllers/ProductController.php(105)

093 
094     public function actionShowByCategory($category_id){
095         
096         $category = ProductCategory::model()->findByPk($category_id);
097 
098         // get list product with pagination
099         if (!isset(Yii::app() -> session['product_pageSize']))
100             Yii::app() -> session['product_pageSize'] = News::PAGE_SIZE;
101 
102         if(!isset(Yii::app() -> session['product_sort']))
103             Yii::app() -> session['product_sort'] = News::SORT;
104 
105 $list_childs = $category->child_nodes;
106 $list_ids = array();
107 $list_ids[] = $category_id;
108 if(sizeof($list_childs) > 0){
109 foreach($list_childs as $id=>$level){
110 $list_ids[] = $id;
111 }
112 }
113 
114         $criteria = new CDbCriteria();
115         $criteria -> compare('status', true);
116         $criteria -> addInCondition('cat_id', $list_ids);
117         $criteria -> order = Yii::app() -> session['product_sort'];

Stack Trace

#9
+
 /home/quanghuysk/public_html/index.php(19): CApplication->run()
14 if(isset($_GET['iphoenix_language'])){
15     Yii::app()->theme='front-end-'.$_GET['iphoenix_language'];
16     Yii::app()->language = $_GET['iphoenix_language'];
17 }
18 
19 $app->run ();
2024-03-19 07:06:29 Apache Yii Framework/1.1.14