gistfile1.php

<?php

/**
 * Implements hook_theme_registry_alter()
 */
function radius_settings_theme_registry_alter(&$theme_registry) {
  $theme_registry['file_link']['function'] = 'radius_settings_file_link';
}

/**
 * Change the file upload indicator from a text link, to a thumbnail.  This
 * overrides theme_file_link
 *
 * Default behavior: http://i.imgur.com/R6VEqMY.gif
 * Desired behavior: http://i.imgur.com/pBt54DR.png
 *
 * This is used exclusively on settings/personal-info
 *
 * @see
 * _radius_settings_personal_form_submit
 */
function radius_settings_file_link($vars) {
  if (
  (current_path() === 'settings/personal-info') ||
  //This first condition will evaluate as true during an AJAX image upload on settings/personal-info
  (!empty($_REQUEST['form_id']) && $_REQUEST['form_id'] === 'radius_settings_personal_form')
  ) {
    global $user;
    $image = $vars['file'];
    $extension = strtolower(substr($vars['file']->filemime, 6));
    $extension = ($extension === 'jpeg') ? 'jpg' : $extension;

    /**
     * During AJAX upload we want to make a temporary copy of this file in the
     * public:// directory, so that the user can preview their upload.  This
     * avoids the behavior shown in this gif http://i.imgur.com/skH1Zl5.gif
     */
    if (preg_match('/^temporary/', $image->uri)) {
      $image = file_copy($image, 'public://temp/' . $user->name . '.' . $extension);

      /**
       * Store this image in the session, and then delete it when the user
       * submits the form.
       *
       * @todo
       * handle form abandonment, by occasionally deleting the temporary store
       * of images on cron
       */
      $_SESSION['images_to_delete'][] = $image;
    }

    $content = array(
      'file' => array(
        '#theme' => 'image_style',
        '#style_name' => '200x200_square',
        '#path' => $image->uri,
        '#width' => (isset($image->info['width'])) ? $image->info['width'] : NULL,
        '#height' => (isset($image->info['height'])) ? $image->info['height'] : NULL,
      ),
    );
    return drupal_render($content);
  }
  else {
    return theme_file_link($vars);
  }
}