Button visibility in Grid view

array(
'class'=>'bootstrap.widgets.TbButtonColumn',
'template'=>'{view}{edit}{delete}',
'buttons'=>array
(


'view' => array
(
'label'=>'View',
'visible' => '(isset($data->id))?false:true;',
'url'=>'Yii::app()->createUrl("MainMenu/view", array("id"=>$data->id))',
'imageUrl' => Yii::app()->baseUrl . '/images/icon/viewicon.jpg',
'options'=>array(
'style'=>'width:130px;height:130px;',
//   'class'=>'btn btn-small btn-info',
),
),