<?php

/**
 * @file
 * Definition of views_handler_sort_menu_hierarchy.
 */

/**
 * Sort in menu hierarchy order.
 *
 * Given a field name of 'p' this produces an ORDER BY on p1, p2, ..., p9;
 * and optionally injects multiple joins to {menu_links} to sort by weight
 * and title as well.
 *
 * This is only really useful for the {menu_links} table.
 *
 * @ingroup views_sort_handlers
 */
class views_handler_sort_menu_hierarchy extends views_handler_sort {

  /**
   * {@inheritdoc}
   */
  public function option_definition() {
    $options = parent::option_definition();
    $options['sort_within_level'] = array('default' => FALSE);
    return $options;
  }

  /**
   * {@inheritdoc}
   */
  public function options_form(&$form, &$form_state) {
    parent::options_form($form, $form_state);
    $form['sort_within_level'] = array(
      '#type' => 'checkbox',
      '#title' => t('Sort within each hierarchy level'),
      '#description' => t('Enable this to sort the items within each level of the hierarchy by weight and title.  Warning: this may produce a slow query.'),
      '#default_value' => $this->options['sort_within_level'],
    );
  }

  /**
   * {@inheritdoc}
   */
  public function query() {
    $this->ensure_my_table();
    $max_depth = isset($this->definition['max depth']) ? $this->definition['max depth'] : MENU_MAX_DEPTH;
    for ($i = 1; $i <= $max_depth; ++$i) {
      if ($this->options['sort_within_level']) {
        $join = new views_join();
        $join->construct('menu_links', $this->table_alias, $this->field . $i, 'mlid');
        $menu_links = $this->query->add_table('menu_links', NULL, $join);
        $this->query->add_orderby($menu_links, 'weight', $this->options['order']);
        $this->query->add_orderby($menu_links, 'link_title', $this->options['order']);
      }

      // We need this even when also sorting by weight and title, to make sure
      // that children of two parents with the same weight and title are
      // correctly separated.
      $this->query->add_orderby($this->table_alias, $this->field . $i, $this->options['order']);
    }
  }

}