menu_attributes.module in Menu Attributes 8

Alters the menu item form to allow the administrator to specify additional attributes for the menu link

File

menu_attributes.module

<?php

/**
 * @file
 * Alters the menu item form to allow the administrator to specify additional
 * attributes for the menu link
 */
use Drupal\Component\Plugin\Exception\PluginNotFoundException;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Menu\MenuLinkInterface;
use Drupal\Core\Render\Element;
define('MENU_ATTRIBUTES_LINK', 'attributes');
define('MENU_ATTRIBUTES_ITEM', 'item_attributes');

/**
 * Implements hook_ENTITY_TYPE_presave().
 */
function menu_attributes_menu_link_content_presave(EntityInterface $entity) {
  $item = $entity
    ->toArray();
  if (isset($item['options']['attributes']) && is_array($item['options']['attributes'])) {

    // Filter out blank attributes.
    foreach ($item['options']['attributes'] as $key => $value) {
      if (is_array($value) && empty($value) || is_string($value) && !mb_strlen($value)) {
        unset($item['options']['attributes'][$key]);
      }
    }

    // Convert classes to an array.
    if (isset($item['options']['attributes']['class']) && is_string($item['options']['attributes']['class'])) {
      $item['options']['attributes']['class'] = array_filter(explode(' ', $item['options']['attributes']['class']));
    }
  }
}

/**
 * Implements hook_menu_attribute_info().
 */
function menu_attributes_menu_attribute_info() {
  $info['title'] = [
    'label' => t('Title'),
    'description' => t('The description displayed when hovering over the link.'),
    'form' => [
      '#type' => 'textarea',
      '#rows' => 2,
    ],
    'scope' => [
      MENU_ATTRIBUTES_LINK,
    ],
  ];
  $info['id'] = [
    'label' => t('ID'),
    'description' => t('Specifies a unique ID for the link.'),
    'item_description' => t('Specifies a unique ID to be added to the item.'),
    'scope' => [
      MENU_ATTRIBUTES_LINK,
      MENU_ATTRIBUTES_ITEM,
    ],
  ];
  $info['name'] = [
    'label' => t('Name'),
    'scope' => [
      MENU_ATTRIBUTES_LINK,
    ],
  ];
  $info['rel'] = [
    'label' => t('Relationship'),
    'description' => t("Specifies the relationship between the current page and the link. Enter 'nofollow' here to nofollow this link."),
    'scope' => [
      MENU_ATTRIBUTES_LINK,
    ],
  ];
  $info['class'] = [
    'label' => t('Classes'),
    'description' => t('Enter additional classes to be added to the link.'),
    'item_description' => t('Enter additional CSS class names to be added to the item.'),
    'scope' => [
      MENU_ATTRIBUTES_LINK,
      MENU_ATTRIBUTES_ITEM,
    ],
  ];
  $info['style'] = [
    'label' => t('Style'),
    'description' => t('Enter additional styles to be applied to the link.'),
    'item_description' => t('Enter additional styles attribute to be applied to the item.'),
    'scope' => [
      MENU_ATTRIBUTES_LINK,
      MENU_ATTRIBUTES_ITEM,
    ],
  ];
  $info['target'] = [
    'label' => t('Target'),
    'description' => t('Specifies where to open the link. Using this attribute breaks XHTML validation.'),
    'form' => [
      '#type' => 'select',
      '#options' => [
        '' => t('None (i.e. same window)'),
        '_blank' => t('New window (_blank)'),
        '_top' => t('Top window (_top)'),
        '_self' => t('Same window (_self)'),
        '_parent' => t('Parent window (_parent)'),
      ],
    ],
    'scope' => [
      MENU_ATTRIBUTES_LINK,
    ],
  ];
  $info['accesskey'] = [
    'label' => t('Access Key'),
    'description' => t('Specifies a <a href=":url">keyboard shortcut</a> to access this link.', [
      ':url' => 'http://en.wikipedia.org/wiki/Access_keys',
    ]),
    'form' => [
      '#maxlength' => 1,
      '#size' => 1,
    ],
    'scope' => [
      MENU_ATTRIBUTES_LINK,
    ],
  ];
  return $info;
}

/**
 * Fetch an array of menu attributes.
 */
function menu_attributes_get_menu_attribute_info() {
  $module_handler = \Drupal::moduleHandler();
  $attributes = $module_handler
    ->invokeAll('menu_attribute_info');
  $config = \Drupal::config('menu_attributes.settings');

  // Merge in default values.
  foreach ($attributes as $attribute => &$info) {
    $info += [
      'form' => [],
      'enabled' => $config
        ->get('attribute_enable.' . $attribute),
    ];
    $info['form'] += [
      '#type' => 'textfield',
      '#title' => $info['label'],
      '#description' => isset($info['description']) ? $info['description'] : '',
      '#default_value' => $config
        ->get('attribute_default.' . $attribute),
    ];
  }
  $module_handler
    ->alter('menu_attribute_info', $attributes);
  return $attributes;
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * Adds menu attribute options to the edit menu item form.
 *
 * @see _menu_attributes_form_alter()
 * @see menu_attributes_form_menu_edit_item_submit()
 */
function menu_attributes_form_menu_link_edit_alter(array &$form, FormStateInterface $form_state, $form_id) {

  // Although the form itself can be altered to show the attribute fields, there
  // is not currently a proper way to save the attributes without bypassing
  // core's current functionality.
  // @see https://www.drupal.org/node/2656534

  //_menu_attributes_form_alter($form, $form_state, $form_id);
}

/**
 * Implements hook_form_BASE_FORM_ID_alter().
 *
 * Adds menu attribute options to the menu_link_content_form.
 *
 * @see _menu_attributes_form_alter()
 * @see menu_attributes_form_menu_edit_item_submit()
 */
function menu_attributes_form_menu_link_content_form_alter(array &$form, FormStateInterface $form_state, $form_id) {
  $menu_link = $form_state
    ->getFormObject()
    ->getEntity();
  _menu_attributes_form_alter($form, $form_state, $menu_link);
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * Adds menu attribute options to the node's edit menu item form.
 *
 * @see _menu_attributes_form_alter()
 */
function menu_attributes_form_node_form_alter(&$form, FormStateInterface $form_state) {
  if (isset($form['menu']['link']) && isset($form['#node']->menu)) {
    $item = $form['#node']->menu;

    // @todo Need to pass in the form state and menu link.
    // _menu_attributes_form_alter($form['menu']['link'], $form['menu']['link'], $form);
  }
}

/**
 * Add the menu attributes to a menu item edit form.
 *
 * @param $form
 *   The menu item edit form passed by reference.
 * @param $item
 *   The optional existing menu item for context.
 */
function _menu_attributes_form_alter(array &$form, FormStateInterface $form_state, $menu_link) {
  $form['options'][MENU_ATTRIBUTES_LINK] = [
    '#type' => 'details',
    '#title' => t('Menu link attributes'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
    '#tree' => TRUE,
  ];
  $form['options'][MENU_ATTRIBUTES_ITEM] = [
    '#type' => 'details',
    '#title' => t('Menu item attributes'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
    '#tree' => TRUE,
  ];
  $attributes = menu_attributes_get_menu_attribute_info();
  $menu_link_options = $menu_link->link
    ->first()->options ?: [];
  $menu_attributes[MENU_ATTRIBUTES_LINK] = isset($menu_link_options[MENU_ATTRIBUTES_LINK]) ? $menu_link_options[MENU_ATTRIBUTES_LINK] : [];
  $menu_attributes[MENU_ATTRIBUTES_ITEM] = isset($menu_link_options[MENU_ATTRIBUTES_ITEM]) ? $menu_link_options[MENU_ATTRIBUTES_ITEM] : [];
  foreach ($attributes as $attribute => $info) {

    // If no scope is set, this attribute should be available to both item
    // and link.
    if (!isset($info['scope'])) {
      $info['scope'] = [
        MENU_ATTRIBUTES_ITEM,
        MENU_ATTRIBUTES_LINK,
      ];
    }

    // Define fields for each scope.
    foreach ($info['scope'] as $group) {
      if (isset($menu_attributes[$group][$attribute])) {
        $info['form']['#default_value'] = $menu_attributes[$group][$attribute];
      }

      // If the item description is set, override the form description.
      if ($group == MENU_ATTRIBUTES_ITEM && isset($info['item_description'])) {
        $info['form']['#description'] = $info['item_description'];
      }
      $form['options'][$group][$attribute] = $info['form'] + [
        '#access' => $info['enabled'],
      ];
    }
  }

  // Hide the 'description' field since we will be using our own 'title' field.
  if (isset($form['description'])) {
    $form['description']['#access'] = FALSE;
  }

  // Restrict access to the new form elements.
  $has_visible_children = (bool) Element::getVisibleChildren($form['options']['attributes']);
  $user_has_access = \Drupal::currentUser()
    ->hasPermission('administer menu attributes');
  $form['options']['attributes']['#access'] = $has_visible_children && $user_has_access;
  $form['actions']['submit']['#submit'][] = '_menu_attributes_form_submit';
}

/**
 * Form submit handler for menu item links.
 *
 * Move the title attributes value into the 'description' value so that it
 * will get properly saved.
 */
function _menu_attributes_form_submit($form, FormStateInterface $form_state) {
  $menu_link = $form_state
    ->getFormObject()
    ->getEntity();
  $options = [
    MENU_ATTRIBUTES_LINK => $form_state
      ->getValue(MENU_ATTRIBUTES_LINK),
    MENU_ATTRIBUTES_ITEM => $form_state
      ->getValue(MENU_ATTRIBUTES_ITEM),
  ];
  $menu_link->link
    ->first()->options = $options;
  $menu_link
    ->save();
}

/**
 * Implements MODULE_preprocess_HOOK().
 *
 * Adds appropriate attributes to the list item.
 *
 * @see theme_menu_link()
 */
function menu_attributes_preprocess_menu_link(&$variables) {
  $options =& $variables['element']['#localized_options'];
  $attributes =& $variables['element']['#attributes'];
  if (isset($options['item_attributes'])) {
    foreach ($options['item_attributes'] as $attribute => $value) {
      if (!empty($value)) {

        // Class get's special treatment, as it's an array and it should not
        // replace existing values.
        if ($attribute == 'class') {
          $value = is_array($value) ? explode(' ', $value) : $value;
          if (isset($attributes[$attribute])) {
            $value = array_merge($attributes[$attribute], $value);
          }
        }

        // Override the attribute.
        $attributes[$attribute] = $value;
      }
    }

    // Clean up, so we're not passing this to l().
    unset($options['item_attributes']);
  }
}

/**
 * Implements hook_preprocess_menu().
 */
function menu_attributes_preprocess_menu(&$variables) {
  menu_attributes_set_attributes($variables['items']);
}

/**
 * Set the attributes recursively on the given menu items.
 *
 * @param array $items
 *   An array of menu items.
 */
function menu_attributes_set_attributes($items) {
  foreach ($items as &$item) {
    $menu_attributes = [];
    if (!empty($item['original_link'])) {
      $menu_attributes = menu_attributes_get_attributes($item['original_link']);
    }
    $menu_link_attributes = empty($menu_attributes[MENU_ATTRIBUTES_LINK]) ? [] : array_filter($menu_attributes[MENU_ATTRIBUTES_LINK]);
    $menu_item_attributes = empty($menu_attributes[MENU_ATTRIBUTES_ITEM]) ? [] : array_filter($menu_attributes[MENU_ATTRIBUTES_ITEM]);
    if (count($menu_link_attributes)) {
      $url_attributes = $item['url']
        ->getOption('attributes') ?: [];
      $attributes = array_merge($url_attributes, $menu_link_attributes);
      $item['url']
        ->setOption('attributes', $attributes);
    }
    if (count($menu_item_attributes)) {
      foreach ($menu_item_attributes as $attribute => $info) {
        $item['attributes']
          ->setAttribute($attribute, $info);
      }
    }
    if (!empty($item['below'])) {
      menu_attributes_set_attributes($item['below']);
    }
  }
}

/**
 * Get menu link attributes.
 *
 * @param \Drupal\Core\Menu\MenuLinkInterface $menu_link_content_plugin
 *
 * @return array
 */
function menu_attributes_get_attributes(MenuLinkInterface $menu_link_content_plugin) {
  $attributes = [];
  if (!$menu_link_content_plugin instanceof \Drupal\menu_link_content\Plugin\Menu\MenuLinkContent) {
    return $attributes;
  }
  try {
    $plugin_id = $menu_link_content_plugin
      ->getPluginId();
  } catch (PluginNotFoundException $e) {
    return $attributes;
  }
  if (strpos($plugin_id, ':') === FALSE) {
    return $attributes;
  }
  list($entity_type, $uuid) = explode(':', $plugin_id, 2);
  $entity = \Drupal::service('entity.repository')
    ->loadEntityByUuid($entity_type, $uuid);
  if ($entity) {
    $options = $entity->link
      ->first()->options;
    $attributes[MENU_ATTRIBUTES_LINK] = isset($options[MENU_ATTRIBUTES_LINK]) ? $options[MENU_ATTRIBUTES_LINK] : [];
    $attributes[MENU_ATTRIBUTES_ITEM] = isset($options[MENU_ATTRIBUTES_ITEM]) ? $options[MENU_ATTRIBUTES_ITEM] : [];

    // Class attribute needs special handling because it's stored as an array.
    if (isset($attributes[MENU_ATTRIBUTES_LINK]['class'])) {
      $attributes[MENU_ATTRIBUTES_LINK]['class'] = explode(' ', $attributes[MENU_ATTRIBUTES_LINK]['class']);
    }
    if (isset($attributes[MENU_ATTRIBUTES_ITEM]['class'])) {
      $attributes[MENU_ATTRIBUTES_ITEM]['class'] = explode(' ', $attributes[MENU_ATTRIBUTES_ITEM]['class']);
    }
  }
  return $attributes;
}

Functions

Name	Description
menu_attributes_form_menu_link_content_form_alter	Implements hook_form_BASE_FORM_ID_alter().
menu_attributes_form_menu_link_edit_alter	Implements hook_form_FORM_ID_alter().
menu_attributes_form_node_form_alter	Implements hook_form_FORM_ID_alter().
menu_attributes_get_attributes	Get menu link attributes.
menu_attributes_get_menu_attribute_info	Fetch an array of menu attributes.
menu_attributes_menu_attribute_info	Implements hook_menu_attribute_info().
menu_attributes_menu_link_content_presave	Implements hook_ENTITY_TYPE_presave().
menu_attributes_preprocess_menu	Implements hook_preprocess_menu().
menu_attributes_preprocess_menu_link	Implements MODULE_preprocess_HOOK().
menu_attributes_set_attributes	Set the attributes recursively on the given menu items.
_menu_attributes_form_alter	Add the menu attributes to a menu item edit form.
_menu_attributes_form_submit	Form submit handler for menu item links.

Constants

Name	Description
MENU_ATTRIBUTES_ITEM
MENU_ATTRIBUTES_LINK