WC_REST_Posts_Controller::get_items PHP Method

    public function get_items($request)
    {
        $args = array();
        $args['offset'] = $request['offset'];
        $args['order'] = $request['order'];
        $args['orderby'] = $request['orderby'];
        $args['paged'] = $request['page'];
        $args['post__in'] = $request['include'];
        $args['post__not_in'] = $request['exclude'];
        $args['posts_per_page'] = $request['per_page'];
        $args['name'] = $request['slug'];
        $args['post_parent__in'] = $request['parent'];
        $args['post_parent__not_in'] = $request['parent_exclude'];
        $args['s'] = $request['search'];
        $args['date_query'] = array();
        // Set before into date query. Date query must be specified as an array of an array.
        if (isset($request['before'])) {
            $args['date_query'][0]['before'] = $request['before'];
        }
        // Set after into date query. Date query must be specified as an array of an array.
        if (isset($request['after'])) {
            $args['date_query'][0]['after'] = $request['after'];
        }
        if (is_array($request['filter'])) {
            $args = array_merge($args, $request['filter']);
            unset($args['filter']);
        }
        // Force the post_type argument, since it's not a user input variable.
        $args['post_type'] = $this->post_type;
        /**
         * Filter the query arguments for a request.
         *
         * Enables adding extra arguments or setting defaults for a post
         * collection request.
         *
         * @param array           $args    Key value array of query var to query value.
         * @param WP_REST_Request $request The request used.
         */
        $args = apply_filters("woocommerce_rest_{$this->post_type}_query", $args, $request);
        $query_args = $this->prepare_items_query($args, $request);
        $posts_query = new WP_Query();
        $query_result = $posts_query->query($query_args);
        $posts = array();
        foreach ($query_result as $post) {
            if (!wc_rest_check_post_permissions($this->post_type, 'read', $post->ID)) {
                continue;
            }
            $data = $this->prepare_item_for_response($post, $request);
            $posts[] = $this->prepare_response_for_collection($data);
        }
        $page = (int) $query_args['paged'];
        $total_posts = $posts_query->found_posts;
        if ($total_posts < 1) {
            // Out-of-bounds, run the query again without LIMIT for total count
            unset($query_args['paged']);
            $count_query = new WP_Query();
            $count_query->query($query_args);
            $total_posts = $count_query->found_posts;
        }
        $max_pages = ceil($total_posts / (int) $query_args['posts_per_page']);
        $response = rest_ensure_response($posts);
        $response->header('X-WP-Total', (int) $total_posts);
        $response->header('X-WP-TotalPages', (int) $max_pages);
        $request_params = $request->get_query_params();
        if (!empty($request_params['filter'])) {
            // Normalize the pagination params.
            unset($request_params['filter']['posts_per_page']);
            unset($request_params['filter']['paged']);
        }
        $base = add_query_arg($request_params, rest_url(sprintf('/%s/%s', $this->namespace, $this->rest_base)));
        if ($page > 1) {
            $prev_page = $page - 1;
            if ($prev_page > $max_pages) {
                $prev_page = $max_pages;
            }
            $prev_link = add_query_arg('page', $prev_page, $base);
            $response->link_header('prev', $prev_link);
        }
        if ($max_pages > $page) {
            $next_page = $page + 1;
            $next_link = add_query_arg('page', $next_page, $base);
            $response->link_header('next', $next_link);
        }
        return $response;
    }