Unique Ubercart catalog page classes

If you have an Ubercart E-commerce website built with Drupal 6 and need to need theme different catalog pages differently, you are not alone. I recently ran into a situation that required links to be a different color on a specific catalog page. That part was fairly easy as there were unique body classes available for each page (I was using a Zen subtheme). However, it was not intuitive getting all the children terms of that catalog page to show up the same way.

Turns out there is a fairly easy solution to add an additional body class to the theme that will point to the parent taxonomy item. Note: This was only tested with a simple taxonomy structure, no guarantees that it will work if your taxonomy structure is overly complicated.

Just add this to your theme:

function MYTHEME_preprocess_page(&$vars) {
  $arg0 = arg(0);
  $arg1 = arg(1);
  if (isset($arg0) && $arg0 == 'catalog' && isset($arg1) && is_numeric($arg1)) {
    $parents = taxonomy_get_parents($arg1);
    if (!empty($parents) && $parent = array_pop($parents)) {
      $vars['body_classes'] .= ' catalog-parent-' . $parent->tid;
    }
  }
}

All the above does is add an additional class on the body html tag that looks something like "catalog-parent-[TID]" where the [TID] is replaced with the taxonomy term id of the parent taxonomy term. For example, assume you had a taxonomy structure for your store catalog that looked like this:

- Shirts (tid = 1)
-- T-Shirts
-- Dress Shirts
- Boots (tid = 2)
-- Work Boots
-- Western Boots

If you now navigate to the "T-Shirts" catalog page, there will be a unique class on the body tag of your HTML with a class name of "catalog-parent-1". You could use this to theme the page differently in your CSS code.