FluidTYPO3\Fluidpages\Service\ConfigurationService::resolvePageProvider PHP Method

    public function resolvePageProvider($row)
    {
        $provider = $this->resolvePrimaryConfigurationProvider('pages', PageProvider::FIELD_NAME_MAIN, $row);
        return $provider;
    }

 /**
  * @param integer $pageUid Starting page UID in the rootline (this current page)
  * @return array
  */
 protected function getBackendLayoutConfiguration($pageUid)
 {
     try {
         $record = $this->recordService->getSingle('pages', '*', $pageUid);
         // Stop processing if no fluidpages template configured in rootline
         if (null === $record) {
             return [];
         }
         $provider = $this->configurationService->resolvePageProvider($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 [];
         }
         $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 [];
         }
     } catch (\Exception $error) {
         $this->configurationService->debug($error);
         return [];
     }
     $config = ['colCount' => 0, 'rowCount' => 0, 'rows.' => []];
     $rowIndex = 0;
     foreach ($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 ? $column['colPos'] : null];
             if ($column['colspan']) {
                 $columns[$key]['colspan'] = $column['colspan'];
             }
             if ($column['rowspan']) {
                 $columns[$key]['rowspan'] = $column['rowspan'];
             }
             $colCount += $column['colspan'] ? $column['colspan'] : 1;
             ++$index;
         }
         $config['colCount'] = max($config['colCount'], $colCount);
         $config['rowCount']++;
         $config['rows.'][$rowKey] = ['columns.' => $columns];
         ++$rowIndex;
     }
     if (false === $this->isPageModuleLanguageView()) {
         $config['rows.'][$rowIndex + 1 . '.'] = ['columns.' => ['1.' => ['name' => LocalizationUtility::translate('fluidContentArea', 'fluidpages'), 'colPos' => ContentService::COLPOS_FLUXCONTENT]]];
     }
     return $config;
 }