ds_extras_tokens.module

<?php

/**
 * Implements hook_theme().
 */
function ds_extras_tokens_theme() {

  // Declare our own theme hook, to add to the
  // theme_hook_suggestions for 'field'
  return array(
    'theme_ds_field_expert_tokens' => array(
      'render element' => 'element',
      'function' => 'theme_ds_field_expert_tokens',
    )
  );
}

/**
 * Implements hook_theme_registry_alter().
 */
function ds_extras_tokens_theme_registry_alter(&$theme_registry) {
  // Add our preprocess function, which handles adding theme hook suggestions 
  $theme_registry['field']['preprocess functions'][] = 'ds_extras_tokens_preprocess_field';
}

/**
 * Theme preprocess function for 'field'.
 * @see ds_extras_tokens_theme_registry_alter()
 */
function ds_extras_tokens_preprocess_field(&$vars) {

  // We are only overriding theme function when the "Expert" DS Extras template is used
  if (isset($vars['ds-config']) && $vars['ds-config']['func'] == 'theme_ds_field_expert') {
    $vars['theme_hook_suggestions'][0] = 'theme_ds_field_expert_tokens';
  }
}

/**
 * Theme function for field
 */
function theme_ds_field_expert_tokens($vars) {

  // Do our thing
  $vars['label'] = token_replace($vars['label'], array($vars['element']['#entity_type'] => $vars['element']['#object']));
  
  // Hand over to the DS theme function
  return theme('theme_ds_field_expert', $vars);
}