How do I theme the secondary menu?

Question

The following code allows me to print the secondary menu.

<?php print theme('links__system_secondary_menu', array('links' => $secondary_menu, 'attributes' => array('id' => 'secondary-menu', 'class' => 'menu nav navbar-nav secondary hidden-xs'))); ?>     

I get the following output.

<ul id="secondary-menu" class="menu nav navbar-nav secondary hidden-xs">
<li class="menu-6734 first"><a href="/" title="">link 1</a></li>
<li class="menu-6735 first"><a href="/" title="">link 2</a></li>
<li class="menu-6736 first"><a href="/" title="">link 3</a></li>
</ul>

Now, I need to add dropdown to the last menu item but I have no idea how to do it. Any guidance much appreciated!

Answer 1

You can theme secondary menu using THEME_links__system_secondary_menu like the following:

function THEME_links__system_secondary_menu(&$vars) {
  // Get links:
  $links = $vars['links'];
  // Get the index of last menu item.
  end($links);
  $last_ele_index = key($links);
  // Here do your logic by change ...
  // $vars['links']['$last_ele_index'];
}