ElggEntity::canComment PHP Method

    public function canComment($user_guid = 0, $default = null)
    {
        return _elgg_services()->userCapabilities->canComment($this, $user_guid, $default);
    }

 /**
  * Can a user comment on this object?
  *
  * @see ElggEntity::canComment()
  *
  * @param int $user_guid User guid (default is logged in user)
  * @return bool
  * @since 1.8.0
  */
 public function canComment($user_guid = 0)
 {
     $result = parent::canComment($user_guid);
     if ($result !== null) {
         return $result;
     }
     if ($user_guid == 0) {
         $user_guid = elgg_get_logged_in_user_guid();
     }
     // must be logged in to comment
     if (!$user_guid) {
         return false;
     }
     // must be member of group
     if (elgg_instanceof($this->getContainerEntity(), 'group')) {
         if (!$this->getContainerEntity()->canWriteToContainer(get_user($user_guid))) {
             return false;
         }
     }
     // no checks on read access since a user cannot see entities outside his access
     return true;
 }