FluidTYPO3\Fluidpages\Backend\BackendLayout::postProcessBackendLayout PHP Method

    public function postProcessBackendLayout(&$pageUid, &$backendLayout)
    {
        try {
            $record = $this->workspacesAwareRecordService->getSingle('pages', '*', $pageUid);
            // Stop processing if no fluidpages template configured in rootline
            if (null === $record) {
                return null;
            }
            $provider = $this->configurationService->resolvePrimaryConfigurationProvider('pages', 'tx_fed_page_flexform', $record);
            $action = $provider->getControllerActionFromRecord($record);
            if (true === empty($action)) {
                $this->configurationService->message('No template selected - backend layout will not be rendered', GeneralUtility::SYSLOG_SEVERITY_INFO);
                return null;
            }
            $grid = $provider->getGrid($record)->build();
            if (false === is_array($grid) || 0 === count($grid['rows'])) {
                // no grid is defined; we use the "raw" BE layout as a default behavior
                $this->configurationService->message('The selected page template does not contain a grid but the template is itself valid.');
                return null;
            }
        } catch (\RuntimeException $error) {
            $this->configurationService->debug($error);
            return null;
        }
        $config = ['backend_layout.' => ['colCount' => 0, 'rowCount' => 0, 'rows.' => []]];
        $colPosList = [];
        $items = [];
        $rowIndex = 0;
        foreach ($grid['rows'] as $row) {
            $index = 0;
            $colCount = 0;
            $rowKey = $rowIndex + 1 . '.';
            $columns = [];
            foreach ($row['columns'] as $column) {
                $key = $index + 1 . '.';
                $columns[$key] = ['name' => $column['label'], 'colPos' => $column['colPos'] >= 0 ? $column['colPos'] : $config['backend_layout.']['colCount']];
                if ($column['colspan']) {
                    $columns[$key]['colspan'] = $column['colspan'];
                }
                if ($column['rowspan']) {
                    $columns[$key]['rowspan'] = $column['rowspan'];
                }
                array_push($colPosList, $columns[$key]['colPos']);
                array_push($items, [$columns[$key]['name'], $columns[$key]['colPos'], null]);
                $colCount += $column['colspan'] ? $column['colspan'] : 1;
                ++$index;
            }
            $config['backend_layout.']['colCount'] = max($config['backend_layout.']['colCount'], $colCount);
            $config['backend_layout.']['rowCount']++;
            $config['backend_layout.']['rows.'][$rowKey] = ['columns.' => $columns];
            ++$rowIndex;
        }
        unset($backendLayout['config']);
        $backendLayout['__config'] = $config;
        $backendLayout['__colPosList'] = $colPosList;
        $backendLayout['__items'] = $items;
    }

 /**
  * Gets the selected backend layout
  *
  * @param integer $id
  * @return array|NULL $backendLayout
  */
 public function getSelectedBackendLayout($id)
 {
     $this->backendLayout->preProcessBackendLayoutPageUid($id);
     $backendLayout = parent::getSelectedBackendLayout($id);
     $this->backendLayout->postProcessBackendLayout($id, $backendLayout);
     return array('__config' => $backendLayout['__config'], '__items' => $backendLayout['__items'], '__colPosList' => $backendLayout['__colPosList']);
 }