Adding class to nested UL in menu

Question

I'm creating my menu using view along with Bootstrap to create a mega menu style navigation.

I'm having a problem with the nav showing expanded at times when you come to the site and or refresh. not all the time but more than I'd like.

I am using: _menu_link like such:

function MYTHEME_menu_link(array $vars) {
  if ( $vars['element']['#theme'] == 'menu_link__user_menu' ) {
    $vars['element']['#attributes']['class'][] = '';
  }
  elseif ( $vars['element']['#theme'] == 'menu_link__main_menu' ) {
    $vars['element']['#attributes']['class'][] = 'dropdown mm-menu-fw';
    $vars['element']['#localized_options']['attributes']['class'][] = 'url-link';
  }
  return theme_menu_link($vars);
}

This gives me the following HTML markup.

<ul class="dropdown mm-menu-fw">
  <li>
    <a href="#" class="url-link">MY LINK</a>
    <ul class="NEED-TO-ADD-CLASS"></ul>
  </li>
</ul>

Answer 1

You might get into the sub menu element with the ['#below'] object. not tested.

<?php

   /**
    * Implements theme_menu_link__[MENU NAME].
    */
   function YOURTHEME_menu_link__main_menu(&$variables) {       


        $element = $variables['element'];
        $sub_menu = '';         

        $element['#attributes']['class'][] = 'dropdown mm-menu-fw';        
        $element['#localized_options']['attributes']['class'][] = 'url-link';

        if ($element['#below']) 
        {
         $sub_menu = $element['#below']['#attributes']['class'][]= 'NEED-TO-ADD-CLASS';
         drupal_render($sub_menu);
        }

       $output = l($element['#title'], $element['#href'], $element['#localized_options']);

       return '<li' . drupal_attributes($element['#attributes']) . '>' . $output . $sub_menu . "</li>\n";

 }
?>