pantheon_advanced_page_cache.module

<?php

use Drupal\Core\Entity\EntityInterface;
use Drupal\image\Entity\ImageStyle;

/**
 * Implements hook_ENTITY_TYPE_update() for file entities.
 *
 * Clears edge cache by file url. If this is not done, changing file contents
 * does not actually change the file that gets served until the cache times out.
 */
function pantheon_advanced_page_cache_file_update(EntityInterface $file) {
  // Don't try this if we're not in a Pantheon environment.
  if ( ! function_exists('pantheon_clear_edge_paths')) {
    return;
  }
  // No matter what, the file's base URL needs to be cleared out.
  $paths_to_clear = [$file->createFileUrl()];

  // If this is an image, we need to clear the edge cache paths for every
  // image style, or those won't work.
  if ((class_exists(ImageStyle::class)) && (strpos($file->getMimeType(), 'image', 0) === 0)) {
    $styles = ImageStyle::loadMultiple();
    foreach ($styles as $style) {
      $file_uri = $file->getFileUri();
      $url      = $style->buildUrl($file_uri);

      $paths_to_clear[] = parse_url($url)['path'];
    }
  }

  try {
    pantheon_clear_edge_paths($paths_to_clear);
  }
  catch (Exception $e) {
    \Drupal::logger('pantheon_advanced_page_cache')
           ->warning('File upload @filename did not successfully clear edge caches. Caches may need to be cleared manually.',
             ['@filename' => $file->getFileName()]);

    \Drupal::logger('pantheon_advanced_page_cache')
           ->error('@error', ['@error' => $e->getMessage()]);

    return;
  }

  \Drupal::logger('pantheon_advanced_page_cache')
         ->notice('File paths cleared in edge cache: @paths.',
           ['@paths' => implode(', ', $paths_to_clear)]);
}