menu_order_alphabetical.module

<?php

/**
 * @file
 * Contains menu_order_alphabetical.module.
 */

use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\menu_link_content\Entity\MenuLinkContent;
use Drupal\Component\Utility\SortArray;
use Drupal\Core\Url;

/**
 * Implements hook_help().
 */
function menu_order_alphabetical_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the menu_order_alphabetical module.
    case 'help.page.menu_order_alphabetical':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('Add alphabetical order option to the menu ui and menu creation.') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implements hook_entity_type_build().
 */
function menu_order_alphabetical_entity_type_build(array &$entity_types) {
  /* @var $entity_types \Drupal\Core\Entity\EntityTypeInterface[] */
  $entity_types['menu']
    ->setFormClass('reset', 'Drupal\menu_order_alphabetical\Form\MenuLinkTreeResetForm')
    ->setLinkTemplate('reset-form', '/admin/structure/menu/manage/{menu}/reset');
}

/**
 * Implements hook_ENTITY_TYPE_presave().
 *
 * For new menu before saving adapt weight for alphabetical prosition.
 */
function menu_order_alphabetical_menu_link_content_presave(MenuLinkContent $entity) {
  // We only process new menu entries.
  if (!$entity->isNew()) {
    return;
  }
  $id = $entity->getPluginId();
  $menu_name = $entity->getMenuName();
  $root = $entity->getParentId();

  $new_tree = [];
  if ($tree = _menu_order_alphabetical_get_tree($menu_name, $root)) {
    // We have a root so start from this root.
    $tree = reset($tree);
    if (isset($tree->subtree)) {
      foreach ($tree->subtree as $menuLinkTree) {
        $menuLink = $menuLinkTree->link;
        $new_tree[$menuLink->getPluginId()] = [
          'id' => $menuLink->getPluginId(),
          'title' => $menuLink->getTitle(),
          'weight' => $menuLink->getWeight(),
        ];
      }
    }
  }

  if (count($new_tree)) {
    // Sort by title.
    uasort($new_tree, [SortArray::class, 'sortByTitleElement']);
    if (!isset($new_tree[$id])) {
      // Add our new entry to get the position if not here.
      $new_tree[$id] = [
        'id' => $id,
        'title' => $entity->getTitle(),
        'weight' => 0,
      ];
    }
    while (current($new_tree) !== $new_tree[$id]) {
      next($new_tree);
    }
    // Start from our link position.
    current($new_tree);
    prev($new_tree);
    $current = current($new_tree);
    $weight = $current['weight'];
    // Set the same weight as previous menu, Drupal will order
    // alphabetically when same weight.
    $entity->set('weight', $weight);
  }
}

/**
 * Gets the menu tree.
 *
 * @param string $menu_name
 *   Name of the menu.
 * @param string $root
 *   Parent menu.
 * @param int $depth
 *   Depth max of the menu.
 *
 * @return \Drupal\Core\Menu\MenuLinkTreeElement[]
 *   The Drupal menu tree.
 */
function _menu_order_alphabetical_get_tree($menu_name, $root = NULL, $depth = 1) {
  $menu_tree = \Drupal::menuTree();

  // Build the typical default set of menu tree parameters.
  $parameters = $menu_tree->getCurrentRouteMenuTreeParameters($menu_name);
  $parameters->setMaxDepth($depth);
  // Set our parent.
  if ($root) {
    $parameters->setRoot($root);
  }

  // Force the entire tree to be build be setting expandParents to an
  // empty array.
  $parameters->expandedParents = [];
  $parameters->activeTrail = [];

  // Load the tree based on this set of parameters.
  $tree = $menu_tree->load($menu_name, $parameters);

  // Transform the tree using the manipulators you want.
  $manipulators = [
    // Use the default sorting of menu links.
    ['callable' => 'menu.default_tree_manipulators:generateIndexAndSort'],
  ];
  $tree = $menu_tree->transform($tree, $manipulators);

  return $tree;
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function menu_order_alphabetical_form_alter(array &$form, FormStateInterface $form_state, $form_id) {
  $form_ids = [
    'menu_edit_form',
    'menu_edit_bigmenu_form',
    'menu_edit_bigmenu_slice_form',
  ];
  if (in_array($form_id, $form_ids)) {
    $form['actions']['reset_alphabetical'] = [
      '#type' => 'submit',
      '#submit' => ['menu_order_alphabetical_submit_reset'],
      '#value' => t('Reset to alphabetical'),
      '#weight' => (int) $form['actions']['submit']['#weight'] + 1,
    ];

    // Add the parent menu name if any.
    if ($menu_link_parent = \Drupal::routeMatch()->getParameter('menu_link')) {
      $form['parent_reset'] = [
        '#type' => 'hidden',
        '#value' => $menu_link_parent,
      ];
    }
  }
}

/**
 * Redirects to confirmation form for the reset action.
 */
function menu_order_alphabetical_submit_reset(array &$form, FormStateInterface $form_state) {
  $menu = $form_state->getValue('id');
  $menu_parent = $form_state->getValue('parent_reset');
  $form_state->setRedirectUrl(Url::fromRoute('entity.menu_ui.reset_form', ['menu' => $menu, 'menu_link' => $menu_parent]));
}

/**
 * Simple reset function for menu weight.
 *
 * We set all weight to 0, Drupal menu will order by natural title.
 */
function menu_order_alphabetical_reset($menu_name, $parent = NULL) {
  $query = \Drupal::database()->update('menu_tree')
    ->fields([
      'weight' => 0,
    ])
    ->condition('menu_name', $menu_name);
  if ($parent) {
    $query->condition('parent', $parent);
  }
  $query->execute();
  $query = \Drupal::database()->update('menu_link_content_data')
    ->fields([
      'weight' => 0,
    ])
    ->condition('menu_name', $menu_name);
  if ($parent) {
    $query->condition('parent', $parent);
  }
  $query->execute();
  // We need to flush menu cache so the menu_ui match the new weights.
  menu_cache_clear_all();
}