/**
  * Constructor
  *
  * @access public
  * @param
  * @return
  */
 public function __construct($a_parent_obj, $show_content = true, $show_subject = true)
 {
     global $lng, $ilCtrl;
     $this->lng = $lng;
     $this->lng->loadLanguageModule('grp');
     $this->lng->loadLanguageModule('crs');
     $this->ctrl = $ilCtrl;
     $this->setShowSubject($show_subject);
     $this->setId('crs_sub_' . $a_parent_obj->object->getId());
     parent::__construct($a_parent_obj, 'members');
     $this->setFormName('subscribers');
     $this->setFormAction($this->ctrl->getFormAction($a_parent_obj, 'members'));
     $this->addColumn('', 'f', "1");
     $this->addColumn($this->lng->txt('name'), 'lastname', '20%');
     $all_cols = $this->getSelectableColumns();
     foreach ($this->getSelectedColumns() as $col) {
         $this->addColumn($all_cols[$col]['txt'], $col);
     }
     $this->addColumn($this->lng->txt('application_date'), 'sub_time', "10%");
     if ($this->getShowSubject()) {
         $this->addColumn($this->lng->txt('subject'), 'subject', '15%');
     }
     $this->addColumn('', 'mail', '10%');
     $this->addMultiCommand('assignSubscribers', $this->lng->txt('assign'));
     $this->addMultiCommand('refuseSubscribers', $this->lng->txt('refuse'));
     $this->addMultiCommand('sendMailToSelectedUsers', $this->lng->txt('crs_mem_send_mail'));
     $this->setPrefix('subscribers');
     $this->setSelectAllCheckbox('subscribers');
     $this->setRowTemplate("tpl.show_subscribers_row.html", "Services/Membership");
     if ($show_content) {
         $this->enable('sort');
         $this->enable('header');
         $this->enable('numinfo');
         $this->enable('select_all');
     } else {
         $this->disable('content');
         $this->disable('header');
         $this->disable('footer');
         $this->disable('numinfo');
         $this->disable('select_all');
     }
     $this->setExternalSegmentation(true);
     include_once 'Modules/Course/classes/Export/class.ilCourseDefinedFieldDefinition.php';
     self::$has_odf_definitions = ilCourseDefinedFieldDefinition::_hasFields($this->getParentObject()->object->getId());
 }