Adding first / last CSS classes to menus

Question

is that possible, without javascript hacks? like this:

<ul class="my_menu">
  <li class="first"> ... </li>
  <li> ... </li>
  <li> ... </li>
  <li class"with_sub"> ... 
    <ul class="my_menu_sub">
      <li class="first"> ... </li>
      <li> ... </li>
      <li> ... </li>
      <li class="last"> ... </li>
    </ul>
  </li>
  <li> ... </li>
  <li> ... </li>
  <li class="last"> ... </li>
</ul>

Answer 1

A better and simpler approach:

function add_first_and_last($items) {
  $items[1]->classes[] = 'first-menu-item';
  $items[count($items)]->classes[] = 'last-menu-item';
  return $items;
}

add_filter('wp_nav_menu_objects', 'add_first_and_last');

Answer 2

Here is rough snippet that takes care of modifying menu output and adding first/last to first and last class (outer ul is not applied at this stage so doesn't count). Note - requires PHP5 for strripos()

add_filter( 'wp_nav_menu_items', 'first_last_class' );

function first_last_class( $items ) {

    $first = strpos( $items, 'class=' );

    if( false !== $first )
         $items = substr_replace( $items, 'first ', $first+7, 0 );

    $last = strripos( $items, 'class=');

    if( false !== $last )
         $items = substr_replace( $items, 'last ', $last+7, 0 );

    return $items;
}

I am bit stuck with how to make it handle nested lists, but it should get you started at least.

Answer 3

Here is a function for only adding the first/last classes to the parent menu items. For most CSS styling, this is all that is necessary.

function nav_menu_add_classes( $items, $args ) {
    //Add first item class
    $items[1]->classes[] = 'menu-item-first';

    //Add last item class
    $i = count($items);
    while($items[$i]->menu_item_parent != 0 && $i > 0) {
        $i--;
    }
    $items[$i]->classes[] = 'menu-item-last';

    return $items;
}
add_filter( 'wp_nav_menu_objects', 'nav_menu_add_classes', 10, 2 );

Answer 4

Learn more about the new Menus API in wordpress 3. You can give any element it's own class manually. Also, once mastered, it makes menus a thing of joy to edit.

Answer 5

If you have nested menus

function add_first_and_last($items) {
    // first class on parent most level
    $items[1]->classes[] = 'first';
    // separate parents and children
    $parents = $children = array();
    foreach($items as $k => $item){
        if($item->menu_item_parent == '0'){
            $parents[] = $k;
        } else {
            $children[$item->menu_item_parent] = $k;
        }
    }
    // last class on parent most level
    $last = end(array_keys($parents));
    foreach ($parents as $k => $parent) {
        if ($k == $last) {
            $items[$parent]->classes[] = 'last';
        }
    }
    // last class on children levels
    foreach($children as $child){
        $items[$child]->classes[] = 'last';
    }
    // first class on children levels
    $r_items = array_reverse($items, true);
    foreach($r_items as $k => $item){
        if($item->menu_item_parent !== '0'){
            $children[$item->menu_item_parent] = $k;
        }
    }
    foreach($children as $child){
        $items[$child]->classes[] = 'first';
    }
    return $items;
}
add_filter('wp_nav_menu_objects', 'add_first_and_last');

I like the simplicity of Ismaelj's answer, but there needs to be more if you want sub-menu classes.

Answer 6

If you don't need support for IE8 or lower, don't forget that you can also use pure CSS:

.my_menu > :first-child,
.my_menu > :last-child {
    /* some styles */
}

jQuery browser support is even better, but it sounds like you're trying to avoid that.

Answer 7

Here is some better code for adding first and last menu item classes that includes support for nested submenus.

add_filter( 'wp_nav_menu_objects', 'tgm_filter_menu_class', 10, 2 );
/**
 * Filters the first and last nav menu objects in your menus
 * to add custom classes.
 *
 * This also supports nested menus.
 *
 * @since 1.0.0
 *
 * @param array $objects An array of nav menu objects
 * @param object $args Nav menu object args
 * @return object $objects Amended array of nav menu objects with new class
 */
function tgm_filter_menu_class( $objects, $args ) {

    // Add first/last classes to nested menu items
    $ids        = array();
    $parent_ids = array();
    $top_ids    = array();
    foreach ( $objects as $i => $object ) {
        // If there is no menu item parent, store the ID and skip over the object
        if ( 0 == $object->menu_item_parent ) {
            $top_ids[$i] = $object;
            continue;
        }

        // Add first item class to nested menus
        if ( ! in_array( $object->menu_item_parent, $ids ) ) {
            $objects[$i]->classes[] = 'first-menu-item';
            $ids[]          = $object->menu_item_parent;
        }

        // If we have just added the first menu item class, skip over adding the ID
        if ( in_array( 'first-menu-item', $object->classes ) )
            continue;

        // Store the menu parent IDs in an array
        $parent_ids[$i] = $object->menu_item_parent;
    }

    // Remove any duplicate values and pull out the last menu item
    $sanitized_parent_ids = array_unique( array_reverse( $parent_ids, true ) );

    // Loop through the IDs and add the last menu item class to the appropriate objects
    foreach ( $sanitized_parent_ids as $i => $id )
        $objects[$i]->classes[] = 'last-menu-item';

    // Finish it off by adding classes to the top level menu items
    $objects[1]->classes[] = 'first-menu-item'; // We can be assured 1 will be the first item in the menu :-)
    $objects[end( array_keys( $top_ids ) )]->classes[] = 'last-menu-item';

    // Return the menu objects
    return $objects;

}

You can find the gist here and the associated tutorial here.

Answer 8

How about:

 ul li:last-child{
     // do something with the last li
 }

and maybe some http://selectivizr.com/

Answer 9

Pure CSS, works for me. This will work with submenus also

ul.nav>li:last-of-type a