How to add item to $vars[breadcrumb] in Drupal

Question

The current breadcrumb only shows 'home'. I would like to update it so it shows 'home>shoes>Tennis Shoe' where 'shoes' is referenced content type(product display) and 'Tennis shoes' the instance(node) title of that content type

Here is how i tried to accomplish this.

I would push additional items(shoes, tennis shoe) into vars[breadcrumb] at page level(theme_preprocess_page) as following:

function THEME_preprocess_page(&$vars, $hook) {
...
$vars['breadcrumb'][] = '<a href="/shoes">shoes<a>';
$vars['breadcrumb'][] = '<a href="/shoes/tennis-shoe">Tennis Shoe<a>';
...
}

And then let my theme_breadcrumb() handle it as it walks through the array:

function THEME_breadcrumb($variables) {
    $breadcrumb = $variables['breadcrumb'];
    if (!empty($breadcrumb)) {
        $breadcrumbs = '<ul class="breadcrumb">';
        $count = count($breadcrumb) - 1;
        foreach ($breadcrumb as $key => $value) {
            if ($count != $key) {
                $breadcrumbs .= '<li>' . $value . '<span class="divider">/</span></li>';
            }
            else{
                $breadcrumbs .= '<li>' . $value . '</li>';
            }
        }
        $breadcrumbs .= '</ul>';
        return $breadcrumbs;
    }
}

This doesn't work. Whenever I add the items to the vars['breadcrumb'] in the preprocessor function as showed above, it never goes to 'THEME_breadcrumb', instead displays 'array' text. (apparently, it expects non array at vars['breadcrumb']) How do you manipulate breadcrumbs? Whats wrong with my reasoning? Thank You

Drupal 7, base of boostrap theme

Answer 1

I hope that you have set $breadcrumb in page.tpl.php. Secondly, you do not need to do it by using theme_preprocess_page.

Just implement using THEME_breadcrumb like this:

function theme_breadcrumb($variables) {
  $breadcrumb = $variables['breadcrumb'];
  $output = '';
  if ((arg(0) == 'node') && is_numeric(arg(1)) && ($node = node_load(arg(1)))) {
    if ($node->type == 'TYPE NAME') {
      $breadcrumb[] = $node->title;
    }
  }
  if (!empty($breadcrumb)) {
    $output.= '<div class="breadcrumb">' . implode(' › ', $breadcrumb) . '</div>';
  }
  return $output;
}

Answer 2

You can also use drupal_set_breadcrumb() in your template_preprocess_page() hook. Something like:

function THEMENAME_preprocess_page(&$variables) {
  // Wrap the code below with some logic here to target just content type you want, like
  // an if() block that looks for $variables['type'] == 'shoe' or whatever

  // Building breadcrumbs
  $breadcrumb = array();
  $breadcrumb[] = l('Home', '<front>');
  $breadcrumb[] = l('Shoes', 'shoes');
  // Setting breadcrumbs
  drupal_set_breadcrumb($breadcrumb);
}

This only sets the breadcrumb trail, so the current page title will automatically be placed at the end of the breadcrumbs.