imagecache_external.module in Imagecache External 7

File

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
 *
 */

/**
 * Implements hook_menu().
 */
function imagecache_external_menu() {

  // more complex menu item
  $items['admin/config/media/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/config/media/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/config/media/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;
}

/**
 * Implements hook_permission().
 */
function imagecache_external_permission() {
  return array(
    'View external images' => array(
      'title' => t('View external images'),
      'description' => t('TODO Add a description for \'View external images\''),
    ),
    'Fetch external images' => array(
      'title' => t('Fetch external images'),
      'description' => t('TODO Add a description for \'Fetch external images\''),
    ),
    'Administer imagecache external' => array(
      'title' => t('Administer imagecache external'),
      'description' => t('TODO Add a description for \'Administer imagecache external\''),
    ),
    'Bypass black/white list' => array(
      'title' => t('Bypass black/white list'),
      'description' => t('TODO Add a description for \'Bypass black/white list\''),
    ),
  );
}

/**
 * Implements hook_theme().
 */
function imagecache_external_theme() {
  return array(
    // Theme functions in image.module.
    'imagecache_external' => array(
      'variables' => array(
        'style_name' => NULL,
        'path' => NULL,
        'alt' => '',
        'title' => NULL,
        'attributes' => array(),
      ),
    ),
  );
}

/**
 * Returns HTML for an image using a specific image style.
 *
 * @param $variables
 *   An associative array containing:
 *   - style_name: The name of the style to be used to alter the original image.
 *   - path: The path of the image file relative to the Drupal files directory.
 *     This function does not work with images outside the files directory nor
 *     with remotely hosted images.
 *   - alt: The alternative text for text-based browsers.
 *   - title: The title text is displayed when the image is hovered in some
 *     popular browsers.
 *   - attributes: Associative array of attributes to be placed in the img tag.
 *
 * @ingroup themeable
 */
function theme_imagecache_external($variables) {
  if ($variables['path'] = imagecache_external_generate_path($variables['path'], $variables['style_name'])) {
    return theme('image_style', $variables);
  }
}

/**
 * Util to generate a path to an image
 * @param $url string the url to the image
 * @param $preset imagecache preset
 * @return string the url to the image
 */
function imagecache_external_generate_path($url, $preset) {

  // Create the extenal images directory and ensure it's writable.
  $hash = md5($url);
  $scheme = file_default_scheme();
  $directory = $scheme . '://imagecache/' . $preset . '/externals/' . $hash;
  if (file_prepare_directory($directory, FILE_CREATE_DIRECTORY | FILE_MODIFY_PERMISSIONS)) {
    $file = imagecache_external_fetch($url, $directory);
    if ($file) {
      return $file->uri;
    }
  }

  //we couldn't get the file
  return FALSE;
}

/**
 * Api function to fetch a url
 * @param $url string url to fetch
 */
function imagecache_external_fetch($url, $cachepath) {

  //now we test it against the whitelist/blacklist
  if (!$url) {
    return FALSE;
  }

  //extract hostname from url
  $parsed_url = parse_url($url);
  $host = $parsed_url['host'];
  $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', 'white') == 'black' && in_array($host, $list) || variable_get('imagecache_external_option', 'white') == 'white' && !in_array($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 FALSE;
  }
  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 FALSE;
  }
  $result = drupal_http_request($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->headers['content-type'], $types)) {
    return file_save_data($result->data, $cachepath, FILE_EXISTS_REPLACE);
  }
  else {

    //if we are unsuccessful then log a message in watchdog
    watchdog('imagecache_external', 'The image ' . $url . ' could not be retrieved');
    return FALSE;
  }
}

Functions

Name	Description
imagecache_external_fetch	Api function to fetch a url
imagecache_external_generate_path	Util to generate a path to an image
imagecache_external_menu	Implements hook_menu().
imagecache_external_permission	Implements hook_permission().
imagecache_external_theme	Implements hook_theme().
theme_imagecache_external	Returns HTML for an image using a specific image style.