public static function HighContrastBlockView::preRender in High contrast 8

#pre_render callback: Sets high contrast cacheability metadata on blocks.

Scans all blocks to see if they depend on the system.theme.global cache tag. If so, also make them depend on the high contrast cacheability metadata.

File

src/HighContrastBlockView.php, line 21

Class

HighContrastBlockView

Provides a trusted callback to alter the system branding block.

Namespace

Drupal\high_contrast

Code

public static function preRender(array $build) {
  $cacheable_metadata = CacheableMetadata::createFromRenderArray($build);

  // Add cacheable data for blocks depending on config:system.site cache tags.
  // Todo: The system branding block does not correctly declare its dependency
  // on system.theme.global.
  $tags = $cacheable_metadata
    ->getCacheTags();
  if (in_array('config:system.site', $tags)) {
    $config = \Drupal::config('high_contrast.settings');

    // Always create a cache context for the no-whitelabel version.
    $cacheable_metadata
      ->addCacheContexts([
      'high_contrast',
    ]);
    $cacheable_metadata
      ->addCacheableDependency($config);

    // Add cacheable metadata.
    $cacheable_metadata
      ->applyTo($build);
  }
  return $build;
}