createFilter example

// Redirect if blog's category is not a child of the current shop's category         $shopCategory = $this->get('shop')->getCategory();
        $category = $this->getCategoryRepository()->findOneBy(['id' => $categoryId, 'active' => true]);
        $isChild = ($shopCategory && $category instanceof Category) ? $category->isChildOf($shopCategory) : false;
        if (!$isChild) {
            throw new Enlight_Controller_Exception('Blog category missing, non-existent or invalid for the current shop', 404);
        }

        $perPage = $this->getPerPage($this->Request(), $this->container->get('session'));

        $filter = $this->createFilter($filterDate, $filterAuthor, $filterTags);

        // Start for Limit         $limitStart = ($page - 1) * $perPage;
        $limitEnd = $perPage;

        // Get all blog articles         $query = $this->getCategoryRepository()->getBlogCategoriesByParentQuery($categoryId);
        $blogCategoryIds = array_column($query->getArrayResult(), 'id');
        $blogCategoryIds[] = $categoryId;
        $shopId = (int) $this->get('shop')->getId();
        $blogArticlesQuery = $this->getRepository()->getListQuery($blogCategoryIds, $limitStart, $limitEnd, $filter, $shopId);