In Drupal, how to change the values passed to Pathauto?

Question

I have Pathauto configured to generate an alias based on the title of a node, for a specific content type. The problem is that I want to make small changes in this title before Pathauto uses it to generate the alias.

The first comment in this post suggests the use of hook_token_values, but I couldn't really understand how to use it, even after reading the docs. In my tests, when I implement this hook, the alias generated is always "array", which means I'm missing something.

Any help? Thanks.

Answer 1

It might be that you missed to implement hook_token_list as well. Providing a new token is a two step process:

1. Implement hook_token_list to declare the tokens you are going to provide. This will just be the name of the tokens, along with a short explanation, and the information to what type of objects the tokens will apply (e.g. node, user, taxonomy, ...)
2. Implement hook_token_value to actually generate the content of the tokens. This will be called when the tokens are to be replaced with the content they should stand for.

As you just want to provide an alternative version of the title token already provided by the token module, it is probably best to just copy the relevant portions from token_node.inc, stripped down to the relevant cases and adjusted to be used in another module:

/**
 * Implementation of hook_token_list().
 */
function yourModule_token_list($type = 'all') {
  if ($type == 'node' || $type == 'all') {
    $tokens['node']['yourModule-title'] = t('Node title (customized version by yourModule)');

    return $tokens;
  }
}

This simply says that yourModule provides a token for node objects, named yourModule-title, along with a short description. The main work gets done in the other hook:

/**
 * Implementation of hook_token_values().
 */
function yourModule_token_values($type, $object = NULL, $options = array()) {
  $values = array();
  switch ($type) {
    case 'node':
      $node = $object;
      // TODO: Replace the check_plain() call with your own token value creation logic!
      $values['yourModule-title'] = check_plain($node->title);  
      break;
  }

  return $values;
}

This will be called whenever the tokens for node objects are needed, with the node in question being passed as the $object parameter (for a user token, the $type would be 'user', and $object would be the user object, and so on for other types). What it does is creating an array of values, keyed by the token name, with the replacement for that token as the value. The original code from token_node.inc just runs the title through check_plain(), so this would be the place to insert your own logic.

Answer 2

In Drupal 7, the token functionality has been moved to core. Tokens are implemented by the hook_tokens and hook_token_info methods. For usage examples, follow the links provided, and look for links to functions that implement hook_tokens and hook_token_info… I found the statistics_tokens and statistics_token_info functions helpful in understanding how this hook works.

It's probably also worth noting that this hook needs to be implemented by a module… my first attempt I dropped my test functions into the theme's template.php, only to have nothing happen at all :-p