Drupal: Automagically set breadcrumbs for Taxonomy Menu without Menu Position rules.

gistfile1.php

<?php
/**
 * Implements hook_node_view().
 * 
 * Using Taxonomy Menu and you want your breadcrumbs / active trail to follow suit?
 * This snippet will handle that so that your breadcrumbs can / might look like this:
 *  
 *   home >> term A >> subterm B >> node title
 *    
 * How to use:
 *  1) Set the $node->type to the bundle you want to target
 *  2) Set 'field_article_taxonomyreference' to the relevant taxonomy reference field.
 *  3) Profit!!
 *   
 * Why not use Menu Position module?
 *  You could, but you might end up creating a rule per menu item. With taxonomy menu,
 *  and a somewhat complex menu tree, such a solution wouldn't scale well.
 */
function hook_node_view($node, $view_mode, $langcode) {
  if ($node->type == 'article' && $view_mode == 'full') {
    $items = field_get_items('node', $node, 'field_article_taxonomyreference');
    if (!empty($items)) {
      $item = array_pop($items);
      $term = $item['taxonomy_term'];
      $path = taxonomy_menu_create_path($term->vid, $term->tid);

      // Set the active menu_tree path
      menu_tree_set_path('main-menu', $path);

      // Manually set the preferred link for this path so that
      // menu_get_active_trail() returns the proper trail.
      $preferred_links = &drupal_static('menu_link_get_preferred');
      $preferred_links[$_GET['q']][MENU_PREFERRED_LINK] = menu_link_get_preferred($path);

      // Add the node path at the end of the trail.
      $active_trail = menu_set_active_trail();
      $menu_item = array(
        'title' => $node->title,
        'href' => 'node/' . $node->nid,
        'link_path' => 'node/' . $node->nid,
        'type' => MENU_CALLBACK,
        'localized_options' => array(),
      );
      array_push($active_trail, $menu_item);
      menu_set_active_trail($active_trail);
    }
  }
}