Backend\Modules\FormBuilder\Engine\Model::delete PHP Method

    public static function delete($id)
    {
        $id = (int) $id;
        $db = BackendModel::getContainer()->get('database');
        // get field ids
        $fieldIds = (array) $db->getColumn('SELECT i.id FROM forms_fields AS i WHERE i.form_id = ?', $id);
        // we have items to be deleted
        if (!empty($fieldIds)) {
            // delete all fields
            $db->delete('forms_fields', 'form_id = ?', $id);
            $db->delete('forms_fields_validation', 'field_id IN(' . implode(',', $fieldIds) . ')');
        }
        // get data ids
        $dataIds = (array) $db->getColumn('SELECT i.id FROM forms_data AS i WHERE i.form_id = ?', $id);
        // we have items to be deleted
        if (!empty($dataIds)) {
            self::deleteData($dataIds);
        }
        // delete extra
        BackendModel::deleteExtra('FormBuilder', 'widget', array('id' => $id));
        // delete form
        $db->delete('forms', 'id = ?', $id);
    }

 /**
  * Execute the action
  */
 public function execute()
 {
     // get parameters
     $this->id = $this->getParameter('id', 'int');
     // does the item exist
     if ($this->id !== null && BackendFormBuilderModel::exists($this->id)) {
         parent::execute();
         // get all data for the item we want to edit
         $this->record = (array) BackendFormBuilderModel::get($this->id);
         // delete item
         BackendFormBuilderModel::delete($this->id);
         // trigger event
         BackendModel::triggerEvent($this->getModule(), 'after_delete', array('id' => $this->id));
         // user was deleted, so redirect
         $this->redirect(BackendModel::createURLForAction('Index') . '&report=deleted&var=' . rawurlencode($this->record['name']));
     } else {
         // no item found, throw an exceptions, because somebody is f*****g with our URL
         $this->redirect(BackendModel::createURLForAction('Index') . '&error=non-existing');
     }
 }