/**
  * @param $a_set
  * @return bool
  */
 protected function hasAction($a_set)
 {
     $definition = srCertificateDefinition::find((int) $a_set['definition_id']);
     return $definition && $definition->getDownloadable() && parent::hasAction($a_set);
 }
 /**
  * Show all certificates
  *
  */
 public function showCertificates()
 {
     $this->tabs->setSubTabActive("show_certificates");
     $this->showPreviewCertificateInToolbar();
     $options = array('columns' => array('firstname', 'lastname', 'valid_from', 'valid_to', 'file_version', 'status'), 'definition_id' => $this->definition->getId(), 'show_filter' => false);
     $table = new srCertificateTableGUI($this, 'showCertificates', $options);
     $this->tpl->setContent($table->getHTML());
 }