function template_preprocess_formatter_suite_image_embed in Formatter Suite 8

Prepares variables for image embed template.

This template is used by this module's ImageInlineFormatter by way of the 'formatter_suite_image_embed_formatter' template. The template's job is to compare the image width and height to any limits imposed by the formatter, and then optionally embed the styled image as a data URL instead of as a file URL.

Incoming variables:

• 'theme': the name of the theme to use.
• 'attributes': a copy of 'item_attributes'.
• 'width': the original image width.
• 'height': the original image height.
• 'alt': the image's alternative text.
• 'title': (optional) an image title.
• 'uri': the URI of the item or file.
• 'maximumEmbedWidth': (optional) a copy of 'maximumEmbedWidth'.
• 'maximumEmbedHeight': (optional) a copy of 'maximumEmbedHeight'.

Outgoing variables include the above plus:

• 'attributes': a copy of 'attributes'.
• 'width': the styled image width.
• 'height': the styled image height.
• 'alt': the image's alternative text.
• 'title': (optional) an image title.
• 'sizes': (optional) a list of sizes for responsive images, if the image could not be embedded as a data URL.
• 'srcset': (optional) a list of responsive images, if the image could note be embedded as a data URL.
• '#uri': (optional) the URI of the original image if it could not be embedded as a data URL.

Compared to the Drupal core template_preprocess_image(), this function checks if a image is within the maximum embed width/height limits and attempts to load the image to create a data URL. If the image cannot be found, a file URL is used.

Default template: formatter-suite-image-embed-style.html.twig.

Parameters

array $variables: Returns an associative array of theme variables.

File

./formatter_suite.module, line 292

Implements the principal entry points and hooks for the module.

Code

function template_preprocess_formatter_suite_image_embed(array &$variables) {

  // Invoke Drupal core to process variables. This sets up variables with
  // the image width, height, title, etc.
  template_preprocess_image($variables);

  // Check that the image is within our embedding bounds.
  $maximumEmbedWidth = (int) $variables['maximumEmbedWidth'];
  $maximumEmbedHeight = (int) $variables['maximumEmbedHeight'];
  $width = (int) $variables['width'];
  $height = (int) $variables['height'];
  if ($maximumEmbedWidth > 0 && $width > $maximumEmbedWidth || $maximumEmbedHeight > 0 && $height > $maximumEmbedHeight) {

    // The styled image is too large for embedding. The parent class has
    // already set things up to use a file URL. Leave things that way.
    return;
  }

  // Get the real path to the image.
  if (empty($variables['uri']) === FALSE) {
    $originalUri = $variables['uri'];
  }
  elseif (empty($variables['src']) === FALSE) {
    $originalUri = $variables['src'];
  }
  else {

    // Cannot find URI for image. Fall back to whatever the original theme
    // was going to do.
    return;
  }
  $fileSystem = \Drupal::service('file_system');
  $path = $fileSystem
    ->realpath($originalUri);
  if ($path === FALSE || @file_exists($path) === FALSE) {

    // The file does not exist. Curious. Fall back to whatever Drupal core
    // set up for the template.
    return;
  }

  // Get the file's MIME type. We need this for the data URL.
  $mimeType = \Drupal::service('file.mime_type.guesser')
    ->guess($path);

  // Read the file's raw bytes and base64 encode them as a data URL.
  $data = file_get_contents($path);
  $dataUrl = 'data:' . $mimeType . ';base64,' . base64_encode($data);

  // Set the image's source to be the data URL. To prevent this from
  // being overwritten with the image's URI, delete that URI from the
  // variables. Delete the srcset and sizes too, if present.
  $variables['attributes']['src'] = $dataUrl;
  unset($variables['uri']);
  unset($variables['srcset']);
  unset($variables['sizes']);
}