oembedthumbnail.module

<?php
// $Id$

/**
 * @file
 * Includes all the necessary functions for the oEmbed thumbnails module
 */

/**
 * Implements hook_field_formatter_info().
 * Create a new field formatter for link fields.
 */
function oembedthumbnail_field_formatter_info() {
  $formatters = array(
    'oembedthumbnail' => array(
      'label' => t('oEmbed Thumbnail'),
      'field types' => array('link_field'),
      'description' => t('Embeds links as thumbnails if possible - otherwise just links them.'),
      'settings' => array('imagestyle' => ''),
    ),
  );

  return $formatters;
}


/**
 * Implements hook_field_formatter_settings_form().
 * Adds a dropdown to choose image styles on the field settings form.
 */
function oembedthumbnail_field_formatter_settings_form($field, $instance, $view_mode, $form, &$form_state) {
  $display = $instance['display'][$view_mode];
  $settings = $display['settings'];

  $element = array();
  $element['imagestyle'] = array(
    '#title' => t('Image Style'),
    '#type' => 'select',
    '#options' => image_style_options(),
  );

  return $element;
}


/**
 * Implements hook_field_formatter_settings_summary().
 * Adds details to the field formatting sumarry on the fields page.
 */
function oembedthumbnail_field_formatter_settings_summary($field, $instance, $view_mode) {
  $display = $instance['display'][$view_mode];
  $settings = $display['settings'];

  $summary = '';
  $summary .= t('Image Style') . ': ' . (!empty($settings['imagestyle']) ?  $settings['imagestyle'] : 'default');

  return $summary;
}


/**
 * Implements hook_field_formatter_view().
 */
function oembedthumbnail_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  $element = array();

  foreach ($items as $delta => $item) {
    $attributes = array();
    $url = url($item['url'], $item + array('external' => TRUE));
    $attributes = array_filter($display['settings']);

    $element[$delta] = oembedcore_render_cache('oembedthumbnail', $url, $attributes);
  }

  return $element;
}


/**
 * Implements hook_element_info_alter().
 * We need to make sure our pre-render function is called when generating the thumbnail.
 */
function oembedthumbnail_element_info_alter(&$types) {
  $types['oembedthumbnail']['#pre_render'][] = 'oembedthumbnail_pre_render_thumbnail';
}


/**
 * #pre_render callback for 'oembedthumbnail' elements.
 *
 * For oEmbed responses, process the thumbnail image according to the chosen image style
 */
function oembedthumbnail_pre_render_thumbnail($element) {
  // Generate a remote url http://youtube.com/oembed/images/....
  $remote_uri = file_create_url($element['#path']);
  // Check if a remote file object exists in the {file_managed} table for this file...
  $remote_file = remote_stream_wrapper_file_load_by_uri($remote_uri);
  // If there is no file object, create one with the remote url  'http://youtube.com/oembed/images/.....
  if (empty($remote_file)) {
    $remote_file = remote_stream_wrapper_file_create_by_uri($remote_uri);
    file_save($remote_file);  // From Dave Reid... Save the file as file_save will be deprecated in remote_stream_wrapper_file_create_by_uri...
  }
  // Now generate the derivative uri, public://styles/{style_name}/etc........
  $derivative_uri = remote_stream_wrapper_image_style_path($element['#display_options']['imagestyle'], $remote_file->uri);
  // From that internal uri generate an internal derative url, http://mysite.com/files/styles/{style_name}/etc.....
  $element['#path'] = file_create_url($derivative_uri);
  return $element;
}