PHP，致命错误，PHP don ';see"对象

当我print_r或var_dump对象时，我看到了它的所有属性，当我对它执行函数时，例如$data-link()，我得到了错误

Fatal error: Call to a member function link() on a non-object in xyx.php on line 281

public function throwBoxProduct($data,$type = false)
     {
           var_dump($data);
           if($data->category->parent != 0){
                ....
           }
           ......
           <a href="'.$data->link().'" class="product_list_link"></a>
      }

281行的代码如下:

 <a href="'.$data->link().'" class="product_list_link"></a>

var_dump($data)输出如下:

object(Products)#302 (17) { 
    ["sizes"]=> bool(false) ["size"]=> bool(false) ["lay"]=> bool(false) ["lays"]=> bool(false) ["logo"]=> NULL 
    ["categories"]=> array(0) { } ["_new":"CActiveRecord":private]=> bool(false)
    ["_attributes":"CActiveRecord":private]=> array(32) { ["id"]=> string(3) "321" ["category_id"]=> string(2) "15" 
    ["sizes_id"]=> string(0) "" ["title"]=> string(15) "Far" ["intro"]=> string(0) "
}