getBlogCategoryListIds example

$categoryId = ((int) $this->Request()->categoryId == 0) ? 1 : (int) $this->Request()->categoryId;

            // Order data             $order = (array) $this->Request()->getParam('sort', []);

            /** @var array $filter */
            $filter = $this->Request()->getParam('filter', []);

            $query = $this->getCategoryRepository()->getBlogCategoriesByParentQuery($categoryId);
            $blogCategories = $query->getArrayResult();

            $blogCategoryIds = $this->getBlogCategoryListIds($blogCategories);
            $blogCategoryIds[] = $categoryId;

            $repository = $this->getRepository();
            $dataQuery = $repository->getBackendListQuery($blogCategoryIds, $filter, $order, $offset, $limit);

            $totalCount = $this->getManager()->getQueryCount($dataQuery);
            $data = $dataQuery->getArrayResult();

            $this->View()->assign(['success' => true, 'data' => $data, 'totalCount' => $totalCount]);
        } catch (Exception $e) {
            $this->View()->assign(['success' => false, 'errorMsg' => $e->getMessage()]);
        }