remote_stream_wrapper.module in Remote Stream Wrapper 7

Provides a remote stream wrapper and file field integration.

@todo Add a 'Remote URL' file field widget.

File

remote_stream_wrapper.module

<?php

/**
 * @file
 * Provides a remote stream wrapper and file field integration.
 *
 * @todo Add a 'Remote URL' file field widget.
 */

/**
 * Stream wrapper type flag -- visible and readable using remote files that act like local files.
 */
define('STREAM_WRAPPERS_REMOTE', STREAM_WRAPPERS_LOCAL | STREAM_WRAPPERS_READ | STREAM_WRAPPERS_VISIBLE);

/**
 * Implements hook_menu().
 */
function remote_stream_wrapper_menu() {
  $items = array();
  $items['file/add/remote'] = array(
    'title' => 'Remote',
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'remote_stream_wrapper_file_add_form',
    ),
    'access callback' => 'remote_stream_wrapper_media_browser_plugin_access',
    'type' => MENU_LOCAL_TASK,
  );

  // Add image style generation paths for external URLs.
  if (module_exists('image')) {
    $wrappers = file_get_remote_stream_wrappers();
    $directory_path = file_stream_wrapper_get_instance_by_scheme(file_default_scheme())
      ->getDirectoryPath();
    $pos = count(explode('/', $directory_path)) + 1;
    $item = array(
      'page callback' => 'remote_stream_wrapper_image_style_deliver',
      'page arguments' => array(
        $pos,
        $pos + 1,
      ),
      'access callback' => TRUE,
      'type' => MENU_CALLBACK,
      'file' => 'remote_stream_wrapper.image.inc',
    );
    foreach (array_keys($wrappers) as $scheme) {
      $items[$directory_path . '/styles/%image_style/' . $scheme] = $item;
    }
  }
  return $items;
}

/**
 * Implements hook_permission().
 */
function remote_stream_wrapper_permission() {
  $permission = array();
  if (module_exists('media')) {
    $permission['add media from remote urls'] = array(
      'title' => t('Add media from remote URLs'),
      'description' => t('Add media from remote URLs.'),
    );
  }
  return $permission;
}

/**
 * Implements hook_stream_wrappers().
 */
function remote_stream_wrapper_stream_wrappers() {
  $info['http'] = array(
    'name' => t('HTTP URLs'),
    'class' => 'DrupalRemoteStreamWrapper',
    'description' => t('Remote files.'),
    'type' => STREAM_WRAPPERS_REMOTE,
    'remote' => TRUE,
  );
  $info['https'] = $info['http'];
  $info['https']['name'] = t('HTTPS URLs');
  $info['feed'] = $info['http'];
  $info['feed']['name'] = t('Feed URLs');
  return $info;
}

/**
 * Return a list of remote stream wrappers.
 */
function file_get_remote_stream_wrappers() {
  $wrappers =& drupal_static(__FUNCTION__);
  if (!isset($wrappers)) {
    $wrappers = file_get_stream_wrappers(STREAM_WRAPPERS_REMOTE);
    foreach ($wrappers as $scheme => $wrapper) {
      if (empty($wrapper['remote'])) {
        unset($wrappers[$scheme]);
      }
    }

    //$wrappers = array_diff_key($wrappers, file_get_stream_wrappers(STREAM_WRAPPERS_LOCAL_NORMAL
  }
  return $wrappers;
}

/**
 * Check if a stream wrapper scheme is a remote stream wrapper.
 */
function file_is_scheme_remote($scheme) {
  $wrappers = file_get_remote_stream_wrappers();
  return isset($wrappers[$scheme]);
}

/**
 * Implements hook_file_url_alter().
 */
function remote_stream_wrapper_file_url_alter(&$uri) {
  $scheme = file_uri_scheme($uri);
  if ($scheme && file_is_scheme_remote($scheme) && strpos($uri, "{$scheme}://styles/") === 0) {
    $uri = file_default_scheme() . '://' . file_uri_target($uri);
    if (!variable_get('clean_url') && file_uri_scheme($uri) == 'public' && !file_exists($uri)) {
      $directory_path = file_stream_wrapper_get_instance_by_uri($uri)
        ->getDirectoryPath();
      $uri = url($directory_path . '/' . file_uri_target($uri), array(
        'absolute' => TRUE,
      ));
    }
  }
}

/**
 * Copy of image_style_path() for use with remote images.
 *
 * When image_style_path() is give a file like 'http://example.com/image.png'
 * it is converted into 'http://styles/stylename/http/example.com/image.png'
 * which will fail image_style_deliver().
 */
function remote_stream_wrapper_image_style_path($style_name, $uri) {

  // Force the image style to be returned with the default file scheme, but
  // with the file's original scheme in the path.
  return file_default_scheme() . '://styles/' . $style_name . '/' . file_uri_scheme($uri) . '/' . file_uri_target($uri);
}

/**
 * Implements hook_form_FORM_ID_alter().
 *
 * Manually add support for the remote stream wrapper in file fields since
 * it is read-only.
 */
function remote_stream_wrapper_form_field_ui_field_edit_form_alter(&$form, &$form_state) {
  if ($form['#field']['type'] == 'file' || $form['#field']['type'] == 'image') {
    $form['field']['settings']['uri_scheme']['#description'] .= ' ' . t('This only applies to uploaded files and not remote files.');
  }
}

/**
 * Validation callback for remote URLs.
 */
function remote_stream_wrapper_validate_url($element, &$form_state) {
  $value = trim($element['#value']);
  if ($value != '' && !valid_url($value, TRUE)) {
    form_error($element, t('Invalid URL %url.', array(
      '%url' => $value,
    )));
  }
  elseif (!file_stream_wrapper_valid_scheme(file_uri_scheme($value))) {

    // Check that the scheme is supported.
    form_error($element, t('Remote URLs with the %scheme scheme are not supported.', array(
      '%scheme' => file_uri_scheme($value),
    )));
  }
  else {

    // Check that the file exists.
    $request = drupal_http_request($value, array(
      'method' => 'HEAD',
    ));
    if (!empty($request->error)) {
      form_error($element, t('Unable to fetch file from URL %url (error @code: %error).', array(
        '%url' => $value,
        '@code' => $request->code,
        '%error' => $request->error,
      )));
    }
  }
}

/**
 * Load a file object by URI.
 *
 * @param string $uri
 *   A string containing the URI, path, or filename.
 *
 * @return
 *   A file object, or FALSE if not found.
 */
function remote_stream_wrapper_file_load_by_uri($uri) {
  $uri = file_stream_wrapper_uri_normalize($uri);
  $files = entity_load('file', FALSE, array(
    'uri' => $uri,
  ));
  return !empty($files) ? reset($files) : FALSE;
}

/**
 * Helper functon to assemble a new file entity object by URI.
 *
 * @param string $uri
 *   A string containing the URI, path, or filename.
 */
function remote_stream_wrapper_file_create_by_uri($uri) {
  $uri = file_stream_wrapper_uri_normalize($uri);
  $file = new stdClass();
  $file->fid = NULL;
  $file->uri = $uri;
  $file->filename = basename($file->uri);
  $file->filemime = file_get_mimetype($file->uri);
  $file->uid = $GLOBALS['user']->uid;
  $file->status = FILE_STATUS_PERMANENT;
  return $file;
}

/**
 * Implements hook_media_browser_plugin_info().
 */
function remote_stream_wrapper_media_browser_plugin_info() {
  $plugins['remote_file'] = array(
    'title' => t('Remote URL'),
    'class' => 'RemoteStreamWrapperMediaBrowser',
    // Support for Media 1.x browser plugin API.
    '#title' => t('Remote URL'),
    'access callback' => 'remote_stream_wrapper_media_browser_plugin_access',
  );
  return $plugins;
}

/**
 * Media 1.x browser plugin access callback.
 *
 * Duplicate of RemoteStreamWrapperMediaBrowser::access().
 */
function remote_stream_wrapper_media_browser_plugin_access() {
  return user_access('administer files') || user_access('add media from remote urls');
}

/**
 * Implements hook_media_browser_plugin_view().
 */
function remote_stream_wrapper_media_browser_plugin_view($plugin_name, $params) {
  if ($plugin_name == 'remote_file') {
    if (remote_stream_wrapper_media_browser_plugin_access()) {
      $params += array(
        'types' => array(),
      );
      $form = drupal_get_form('remote_stream_wrapper_file_add_form', $params);
      return array(
        '#title' => t('Remote URL'),
        'form' => array(
          $form,
        ),
      );
    }
  }
}

/**
 * Provides a form for adding media items from remote URLs.
 *
 * @see remote_stream_wrapper_media_browser_form_submit()
 */
function remote_stream_wrapper_file_add_form($form, &$form_state, array $options = array()) {
  $form['url'] = array(
    '#type' => 'textfield',
    '#title' => 'URL',
    '#attributes' => array(
      'class' => array(
        'media-add-from-remote-url',
      ),
    ),
    '#maxlength' => 255,
    // Maximum length of {file_managed}.uri
    '#element_validate' => array(
      'remote_stream_wrapper_validate_url',
    ),
    '#required' => TRUE,
  );

  // @todo Validate against file field allowed types.
  $form['#validators'] = array();
  $form['actions'] = array(
    '#type' => 'actions',
  );
  $form['actions']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
  );
  return $form;
}

/**
 * Save a file record based on a remote URL.
 *
 * @see remote_stream_wrapper_media_browser_form()
 * @see file_save()
 * @see DrupalRemoteStreamWrapper
 */
function remote_stream_wrapper_file_add_form_submit($form, &$form_state) {
  $uri = $url = trim($form_state['values']['url']);
  try {
    $file = remote_stream_wrapper_file_load_by_uri($uri);
    if (!$file) {
      $file = remote_stream_wrapper_file_create_by_uri($uri);
      file_save($file);
    }
  } catch (Exception $e) {
    form_set_error('url', $e
      ->getMessage());
    return;
  }
  if (empty($file->fid)) {
    form_set_error('url', t('Unable to add file from URL %file.', array(
      '%file' => $url,
    )));
    return;
  }
  else {
    $form_state['file'] = $file;
  }
  if (drupal_valid_path('file/' . $file->fid . '/edit')) {
    $destination = array(
      'destination' => 'admin/content/file',
    );
    if (isset($_GET['destination'])) {
      $destination = drupal_get_destination();
      unset($_GET['destination']);
    }
    $form_state['redirect'] = array(
      'file/' . $file->fid . '/edit',
      array(
        'query' => $destination,
      ),
    );
  }
  else {
    $form_state['redirect'] = 'admin/content/file';
  }
}

/**
 * Implements hook_file_delete().
 */
function remote_stream_wrapper_file_delete($file) {
  $scheme = file_uri_scheme($file->uri);
  if ($scheme && file_is_scheme_remote($scheme)) {
    remote_stream_wrapper_image_path_flush($file->uri);
  }
}
function remote_stream_wrapper_image_path_flush($path) {
  $styles = image_styles();
  foreach ($styles as $style) {
    $image_path = remote_stream_wrapper_image_style_path($style['name'], $path);
    if (file_exists($image_path)) {
      file_unmanaged_delete($image_path);
    }
  }
}

Functions

Name	Description
file_get_remote_stream_wrappers	Return a list of remote stream wrappers.
file_is_scheme_remote	Check if a stream wrapper scheme is a remote stream wrapper.
remote_stream_wrapper_file_add_form	Provides a form for adding media items from remote URLs.
remote_stream_wrapper_file_add_form_submit	Save a file record based on a remote URL.
remote_stream_wrapper_file_create_by_uri	Helper functon to assemble a new file entity object by URI.
remote_stream_wrapper_file_delete	Implements hook_file_delete().
remote_stream_wrapper_file_load_by_uri	Load a file object by URI.
remote_stream_wrapper_file_url_alter	Implements hook_file_url_alter().
remote_stream_wrapper_form_field_ui_field_edit_form_alter	Implements hook_form_FORM_ID_alter().
remote_stream_wrapper_image_path_flush
remote_stream_wrapper_image_style_path	Copy of image_style_path() for use with remote images.
remote_stream_wrapper_media_browser_plugin_access	Media 1.x browser plugin access callback.
remote_stream_wrapper_media_browser_plugin_info	Implements hook_media_browser_plugin_info().
remote_stream_wrapper_media_browser_plugin_view	Implements hook_media_browser_plugin_view().
remote_stream_wrapper_menu	Implements hook_menu().
remote_stream_wrapper_permission	Implements hook_permission().
remote_stream_wrapper_stream_wrappers	Implements hook_stream_wrappers().
remote_stream_wrapper_validate_url	Validation callback for remote URLs.

Constants

Name	Description
STREAM_WRAPPERS_REMOTE	Stream wrapper type flag -- visible and readable using remote files that act like local files.