How can I add extra info to my menus?

Question

I have some menus that are managed in the standard Menus module (Drupal 6, BTW). I want to add a checkbox when I'm editing a menu item to control the display of a "New" banner via CSS (by adding a class for items that have the checkbox turned on).

I can get my checkbox into the form like so:

function mymodule_form_menu_edit_item_alter(&$form, &$form_state) {
  $form['menu']['newbanner'] = array(
    '#title' => 'New banner',
    '#type' => 'checkboxes',
    '#description' => "Add a 'New' banner to this item?",
    '#options' => array( 'new_banner' => t("This item is new") )
    );
}

But I'm not quite sure how to actually save and use the state of my checkbox. I'm guessing I want to start by creating a mymodule_form_menu_edit_item_submit() function? But how do I get my info in/out of the database and use it to add a class to the generated menu on the front-end?

Answer 1

The code you wrote so far is correct; you just need to add the code for getting the saved setting, and the code to save it.

function mymodule_form_menu_edit_item_alter(&$form, &$form_state) {
  // Get the mlid ID of the menu item.
  $mlid = $form['menu']['mlid']['#value'];

  $form['menu']['newbanner'] = array(
    '#title' => 'New banner',
    '#type' => 'checkboxes',
    '#description' => "Add a 'New' banner to this item?",
    '#default_value' => variable_get("mymodule_newbanner_$mlid", 0),
    '#options' => array('new_banner' => t("This item is new")),
  );

  $form['#submit'][] = 'mymodule_menu_item_submit';
}

function mymodule_menu_item_submit($form, &$form_state) {
  $item = &$form_state['values']['menu'];
  // Get the last ID inserted in the table.
  if (empty($item['mlid'])) {
    $item['mlid'] = db_last_insert_id('menu_links', 'mlid');
  }

  variable_set('mymodule_newbanner_' . $item['mlid'], $item['newbanner']);
}

The mlid could be zero, when the menu item is first created; in that case, the form submission handler gets it from the table, as it is executed after the form submission handler added by menu.module, which saves the menu item in the table using menu_link_save().

Answer 2

Please, please, please do not add your row-level data to the variables table. The entire variables table is cached and loaded on every page, adding to the memory footprint of each page request.

In this case, a variable would be created for every menu item that is saved, which could quickly add up. Though this individual case may not add up to that much extra data, imagine if many modules used the variables table as a data dumping ground.

As a general rule of thumb, if your data has multiple rows, you should probably use a separate table.

Answer 3

You may want to have a look at the Menu attributes module.

This will allow you to set various additional attributes on your menu items including classes and ids which you can then target with css or jquery.

Some more details about this module (from its project page):

This simple module allows you to specify some additional attributes for menu items such as id, name, class, style, and rel.

You should use this module when

• You want to "nofollow" certain menu items to sculpt the flow of PageRank through your site
• You want to give a menu item an ID so you can easily select it using jQuery
• You want to add additional classes or styles to a menu item

The module currently allows you to set the following attributes for each menu item:

• Id
• Name
• Target
• Rel
• Class
• Style
• Accesskey