PHP notice

Trying to get property of non-object

/home/youya/projects/youya/sites/uvic/protected/views/column/_view.php(11)

01 <!-- column box -->
02 <div class="column_box">
03 <a name="cid<?php echo $data->id ?>"></a>
04 <div class="date_box">
05 <div class="year"><?php echo  date("Y",strtotime($data->created_at)) ?></div>
06     <div class="date"><?php echo  date("n月j日",strtotime($data->created_at)) ?></div>
07 </div>
08 <h3><?php echo $data->title ?></h3>
09 <?php echo $data->body ?>
10 <div class="column_footer">
11 <span class="author">posted by <?php echo $data->st->nickname ?></span>
12 <span class="date">DATE:<?php echo date("Y-m-d",strtotime($data->created_at)) ?></span>
13 </div>
14 </div>
15 <!-- end column box -->

Stack Trace

#8
+
 /home/youya/projects/youya/sites/uvic/protected/views/column/view.php(17): CBaseController->widget("zii.widgets.CListView", array("dataProvider" => CActiveDataProvider, "cssFile" => false, "pagerCssClass" => "custom_pager", "itemView" => "_view", ...))
12     'cssFile' => false,
13     'pagerCssClass' => 'custom_pager',
14     'itemView'=>'_view',
15     'ajaxUpdate' => false,
16     'enablePagination' => true,
17 )); ?>
18 </div>
19 <!-- end main content -->
20 </div>
21 <!-- end main -->
22 
#13
+
 /home/youya/projects/youya/sites/uvic/protected/controllers/ColumnController.php(78): CController->render("view", array("dataProvider" => CActiveDataProvider, "category" => Columncategory, "staff" => null, "columnList" => array(Column)))
73             $dataProvider = new CActiveDataProvider('Column',
74                 array(
75                     'criteria' => $c,
76                 )
77             );
78             $this->render('view',array('dataProvider' => $dataProvider,'category' => $category,'staff' => $staff,'columnList' => $columnList));
79 
80 
81         } elseif ($id){
82             $c = new CDbCriteria(
83                 array(
#23
+
 /home/youya/projects/youya/sites/uvic/index.php(13): CApplication->run()
08 defined('YII_DEBUG') or define('YII_DEBUG',true);
09 // specify how many levels of call stack should be shown in each log message
10 defined('YII_TRACE_LEVEL') or define('YII_TRACE_LEVEL',3);
11 
12 require_once($yii);
13 Yii::createWebApplication($config)->run();
2024-03-29 18:58:13 Apache/2.2.16 (Debian) Yii Framework/1.1.12