How to override breadcrumbs defined by a module using a custom module?

Question

Is it possible, using a module, to override a breadcrumd definition defined in another module's hook_node_view()?

• Module property_bc sets a custom breadcrumb for nodes of type Property.
• Module property_bc_plus wants to override that behaviour.

property_bc implementation of hook_node_view would be:

<?php
/**
 * Implementation of hook_node_view().
 */
function property_bc_node_view($node, $view_mode, $langcode) {
  if ($node->type == 'property') {
    $breadcrumb = array();
    $breadcrumb[] = l(t('Home'), NULL);
    $breadcrumb[] = l(check_plain($node->name), "user/$node->uid");
    $breadcrumb[] = l(t('Properties'), "user/$node->uid/properties");
    drupal_set_breadcrumb($breadcrumb);
  }
}

Answer 1

Different solution depending of your context.

• Change the module order by changing their weight: http://drupal.org/node/110238
• Use an other hook than is called later like hook_node_view_alter
• Add a flag in your node and test against it

First module

 <?php
 function property_bc_node_view($node, $view_mode, $langcode) {
      if ($node->type == 'property') {
        $breadcrumb = array();
        $breadcrumb[] = l(t('Home'), NULL);
        $breadcrumb[] = l(check_plain($node->name), "user/$node->uid");
        $breadcrumb[] = l(t('Properties'), "user/$node->uid/properties");
        $node->custom_bredcrumb_is_set = TRUE;
        drupal_set_breadcrumb($breadcrumb);
      }
    }

In your other module

    <?php
    function property_bc_plus_node_view($node, $view_mode, $langcode) {
      if ($node->type == 'property' && isset($node->custom_bredcrumb_is_set) && $node->custom_bredcrumb_is_set != TRUE) {
        $breadcrumb = array();
        $node->custom_bredcrumb_is_set = TRUE;
        drupal_set_breadcrumb($breadcrumb);
      }

}