imagecache_external.module

<?php
/*
 * @file imagecache_external.module
 * Allows imagecache to operate on external images
 * @copyright Copyright(c) 2010 Lee Rowlands
 * @license GPL v2 http://www.fsf.org/licensing/licenses/gpl.html 
 * @author Lee Rowlands contact at rowlandsgroup dot com
 * 
 */

/**
 * Implementation of hook_menu().
 */
function imagecache_external_menu() { 
  // This is the minimum information you can provide for a menu item.
  $items['external'] = array(
    'title' => 'External image',
    'page callback' => 'imagecache_external_image',
    'access arguments' => array('View external images'),
    'type' => MENU_CALLBACK
  );
  // more complex menu item
  $items['admin/settings/imagecache_external'] = array(
    'title' => 'Imagecache External',
    'description' => 'Configure imagecache external',
    'file' => 'imagecache_external.admin.inc',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('imagecache_external_admin_form'),
    'access arguments' => array('Administer imagecache external'),
    'type' => MENU_NORMAL_ITEM, 
  );
  $items['admin/settings/imagecache_external/settings'] = array(
    'title' => 'Settings',
    'description' => 'Configure imagecache external',
    'file' => 'imagecache_external.admin.inc',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('imagecache_external_admin_form'),
    'access arguments' => array('Administer imagecache external'),
    'type' => MENU_DEFAULT_LOCAL_TASK, 
  );
  $items['admin/settings/imagecache_external/flush'] = array(
    'title' => 'Flush external images',
    'description' => 'Flush external images',
    'file' => 'imagecache_external.admin.inc',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('imagecache_external_flush_form'),
    'access arguments' => array('Administer imagecache external'),
    'type' => MENU_LOCAL_TASK, 
  );

  return $items;
}


/**
 * Implementation of hook_perm().
 */
function imagecache_external_perm() {
  return array('View external images', 'Fetch external images', 'Administer imagecache external', 'Bypass black/white list');
}

/**
 * Menu callback does the heavy lifting
*/
function imagecache_external_image() {
  $args = func_get_args();
  $preset = array_shift($args);
  // pop the http:
  array_shift($args);
  $url = 'http://'. implode('/', $args);
  $host = $args[0]; //the host comes first
  //now we test it against the whitelist/blacklist
  if (!$url) {
    return drupal_not_found();
  }
  $list = preg_split('/\s+/', variable_get('imagecache_external_hosts', ''));

  // Check if the list is set as a blacklist and the host is in the list or if
  // the list is set as a whitelist and the host is not found in the list.
  // Note that this is retrospective, ie a previously downloaded image can be blocked
  if (((variable_get('imagecache_external_option', 'black') == 'black' &&
       in_array($host, $list)) ||
      (variable_get('imagecache_external_option', 'black') == 'white' &&
       !in_array($host, $list))) &&
      !user_access('Bypass black/white list')) {
    //if we are unsuccessful then log a message in watchdog
    watchdog('imagecache_external', 'The image '. $url .' could not be retrieved, it did not meet the black/white list requirements.');
    return drupal_access_denied();
  }
  $dir = file_create_path('externals');
  if (!file_check_directory($dir)) {
    mkdir($dir, 0775, FALSE);
  }
  $hash = md5($url);
  $cachepath = file_create_path('externals/'. $hash);
  if (!is_file($cachepath)) {
    if (!user_access('Fetch external images')) {
      watchdog('imagecache_external', 'The image '. $url .' could not be retrieved, the user does not have permission to fetch external images.');
      return drupal_access_denied();
    }
    $result = drupal_http_request($url);
    $code   = floor($result->code / 100) * 100;
    $types  = array('image/jpeg', 'image/png', 'image/gif');
    if ($result->data && $code != 400 && $code != 500 && in_array($result->Content-Type, $types)) {
      $src = file_save_data($result->data, $cachepath);
      $transfer = TRUE;
    }
    else  {
      //if we are unsuccessful then log a message in watchdog
      watchdog('imagecache_external', 'The image '. $url .' could not be retrieved');
      return drupal_not_found();
    }
  }
  else  {
    $transfer = TRUE;
  }
  if ($transfer) {
    $args = explode('/', file_directory_path());
    array_push($args, 'externals', $hash);
    array_unshift($args, $preset);
    return call_user_func_array('imagecache_cache', $args);
  }
}