materio-base-d7/sites/all/modules/gui/materiobasemod/materio_display.module

<?php


/**
 * Implements hook_init().
 */
// function materio_user_init() {
//   drupal_add_js(drupal_get_path('module', 'materio_user').'/js/materio_user.min.js');
// }


/**
 * Implements hook_permission().
 */
function materio_display_permission() {
  return array(
    'view full materiau description' =>  array(
      'title' => t('view full materiau description'),
      'description' => t('view full materiau description'),
    ),
  );
}

/**
 * Implements hook_preprocess().
 */
function materio_display_preprocess_field(&$vars, $hook) {
  // dsm($vars);
  $element = $vars['element'];

  if($element['#field_name'] == 'field_description'){
    // dsm($vars);
    if(!user_access('view full materiau description')){
      $value = $element['#items'][0]['value'];

      switch ($element['#view_mode']) {
        case 'cardbig':
        case 'cardfull':
          $limit = 210;
          break;
        default:
          $limit = 130;
          break;
      }
      $summary = truncate_utf8($value, $limit, TRUE, TRUE);

      $summary .= '<div class="upgrade"><p>'
        . t("In order to access full description, information about manufacturers and more, you need to upgrade your account.")
        . l(t("Pricing"), 'node/11187')
        . '</p></div>';

      // dsm($summary);
      $vars['items'][0]['#markup'] = $summary;

    }
  }

}