Contao\DC_Table::undo PHP Method

    public function undo()
    {
        $objRecords = $this->Database->prepare("SELECT * FROM " . $this->strTable . " WHERE id=?")->limit(1)->execute($this->intId);
        // Check whether there is a record
        if ($objRecords->numRows < 1) {
            $this->redirect($this->getReferer());
        }
        $error = false;
        $query = $objRecords->query;
        $data = \StringUtil::deserialize($objRecords->data);
        if (!is_array($data)) {
            $this->redirect($this->getReferer());
        }
        $arrFields = array();
        // Restore the data
        foreach ($data as $table => $fields) {
            $this->loadDataContainer($table);
            // Get the currently available fields
            if (!isset($arrFields[$table])) {
                $arrFields[$table] = array_flip($this->Database->getFieldNames($table));
            }
            foreach ($fields as $row) {
                // Unset fields that no longer exist in the database
                $row = array_intersect_key($row, $arrFields[$table]);
                // Re-insert the data
                $objInsertStmt = $this->Database->prepare("INSERT INTO " . $table . " %s")->set($row)->execute();
                // Do not delete record from tl_undo if there is an error
                if ($objInsertStmt->affectedRows < 1) {
                    $error = true;
                }
                // Trigger the undo_callback
                if (is_array($GLOBALS['TL_DCA'][$table]['config']['onundo_callback'])) {
                    foreach ($GLOBALS['TL_DCA'][$table]['config']['onundo_callback'] as $callback) {
                        if (is_array($callback)) {
                            $this->import($callback[0]);
                            $this->{$callback[0]}->{$callback[1]}($table, $row, $this);
                        } elseif (is_callable($callback)) {
                            $callback($table, $row, $this);
                        }
                    }
                }
            }
        }
        // Add log entry and delete record from tl_undo if there was no error
        if (!$error) {
            $this->log('Undone ' . $query, __METHOD__, TL_GENERAL);
            $this->Database->prepare("DELETE FROM " . $this->strTable . " WHERE id=?")->limit(1)->execute($this->intId);
        }
        $this->redirect($this->getReferer());
    }