Is it possible to *optionally* override a theme in Drupal 6? - drupal

Question

I want to override the theming of only one (custom) menu. I can do this with phptemplate_menu_tree() but - of course - it overrides the rendering of all menus.
I've tried returning FALSE (an obvious technique IMO) if the menu is not the specific one I want to override - but this doesn't cause the overridden theme function to be called.
My only alternative (when the menu is anything other than the specific one) is to call the overridden function from within phptemplate_menu_tree() - but this seems to defeat the whole point of the override system, since the default rendering function will be hard-coded therein.
I hope the explanation is clear, and any help is greatly appreciated - tks.
UPDATE
For the sake of future reference, I'll explain how I solved this.
First off, the menu rendering starts with this function in menu.module:
function menu_block($op = 'list', $delta = 0) {
$menus = menu_get_menus();
// The Navigation menu is handled by the user module.
unset($menus['navigation']);
if ($op == 'list') {
$blocks = array();
foreach ($menus as $name => $title) {
// Default "Navigation" block is handled by user.module.
$blocks[$name]['info'] = check_plain($title);
// Menu blocks can't be cached because each menu item can have
// a custom access callback. menu.inc manages its own caching.
$blocks[$name]['cache'] = BLOCK_NO_CACHE;
}
return $blocks;
}
else if ($op == 'view') {
$data['subject'] = check_plain($menus[$delta]);
$data['content'] = menu_tree($delta);
return $data;
}
}
If you only want to override how individual item (links) are rendered then you can use the theme system (there are loads of references on how do this) - but if you want complete control on how the entire menu tree is rendered (for example, wrapping the output in nested DIVs so it can be centred on the page) then there is no way to override menu_block().
Therefore, I removed the menu I wanted to render differently from the administer blocks page (site building->blocks) and rendered the menu directly in my page.tpl.php using code something like this: (angle brackets removed)
$m = menu_tree_page_data('my-menu-id');
$o = "DIV";
foreach($m as $k => $v){
$o .= "SPAN {$v['link']['title']} /SPAN";
}
$o .= "/DIV";
echo $o;
I hope this helps.

Answer 1

I've had mixed success doing template.php menu overrides to force CSS classes and ids or HTML into the output.
You could make use of Block Theme when enabling the menu as a block, but I've never tried it.
http://drupal.org/project/blocktheme
If you want to tackle the template way, here are the zen menu override funcitons...
function zen_menu_item_link($link) {
if (empty($link['localized_options'])) {
$link['localized_options'] = array();
}
// If an item is a LOCAL TASK, render it as a tab
if ($link['type'] & MENU_IS_LOCAL_TASK) {
$link['title'] = '<span class="tab">' . check_plain($link['title']) . '</span>';
$link['localized_options']['html'] = TRUE;
}
return l($link['title'], $link['href'], $link['localized_options']);
}
function zen_menu_local_tasks() {
$output = '';
if ($primary = menu_primary_local_tasks()) {
$output .= '<ul class="tabs primary clear-block">' . $primary . '</ul>';
}
if ($secondary = menu_secondary_local_tasks()) {
$output .= '<ul class="tabs secondary clear-block">' . $secondary . '</ul>';
}
return $output;
}

Answer 2

You could use sections module, or look at how it switches theme for certain menu-items.

Answer 3

what I did was register a new theme function in my template.php called primary_links (because I wanted to only customize this menu in certain way) created the function mytheme_primary_links() in my template.php refreshed the cache so Drupal would add my theme function to the system then changed theme function on primary_links from links to my custom theme function primary_links - this allows me to customize only this 1 menu - could you do this and hook into where ever to change the theme function being called for your links?
Chris