Add 'cache_metadata' Twig filter

composer.json

@@ -13,7 +13,8 @@
         "php": ">=7.3",
         "ext-json": "*",
         "drupal/core": "^9.0",
-        "twig/twig": "^2.12"
+        "twig/twig": "^2.12",
+        "symfony/polyfill-php80": "^2.12"
     },
     "suggest": {
         "symfony/var-dumper": "Better dump() function for debugging Twig variables"

docs/cheat-sheet.md

@@ -289,7 +289,6 @@ For string arguments it works similar to core `file_url()` Twig function.
 
 In order to generate absolute URL set "relative" parameter to `false`.
 ```twig
-{{ 'public://sea.jpg'|file_url(relative=false) }}
 {{ 'public://sea.jpg'|file_url(false) }}
 ```
 
@@ -318,6 +317,14 @@ That is typically needed when printing data from referenced entities.
 {{ media|translation.title|view }}
 ```
 
+## Cache metadata
+When using raw values from entities or render arrays it is essential to
+ensure that cache metadata are bubbled up.
+```twig
+<img src="{{ node.field_media|file_url }}" alt="Logo"/>
+{{ content.field_media|cache_metadata }}
+```
+
 ## PHP
 PHP filter is disabled by default. You can enable it in `settings.php` file as
 follows:

src/CacheMetadataExtractor.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Drupal\twig_tweak;
+
+use Drupal\Core\Cache\CacheableDependencyInterface;
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Render\Element;
+
+/**
+ * Cache metadata extractor service.
+ */
+class CacheMetadataExtractor {
+
+  /**
+   * Extracts cache metadata from object or render array.
+   *
+   * @param \Drupal\Core\Cache\CacheableDependencyInterface|array $input
+   *   The cacheable object or render array.
+   *
+   * @return array
+   *   A render array with extracted cache metadata.
+   */
+  public function extractCacheMetadata($input): array {
+    if ($input instanceof CacheableDependencyInterface) {
+      $cache_metadata = CacheableMetadata::createFromObject($input);
+    }
+    elseif (is_array($input)) {
+      $cache_metadata = self::extractFromArray($input);
+    }
+    else {
+      $message = sprintf('The input should be either instance of %s or array. %s was given.', CacheableDependencyInterface::class, \get_debug_type($input));
+      throw new \InvalidArgumentException($message);
+    }
+
+    $build = [];
+    $cache_metadata->applyTo($build);
+    return $build;
+  }
+
+  /**
+   * Extracts cache metadata from renders array.
+   */
+  private function extractFromArray(array $build): CacheableMetadata {
+    $cache_metadata = CacheableMetadata::createFromRenderArray($build);
+    $keys = Element::children($build);
+    foreach (array_intersect_key($build, array_flip($keys)) as $item) {
+      $cache_metadata->addCacheableDependency(self::extractFromArray($item));
+    }
+    return $cache_metadata;
+  }
+
+}

src/TwigTweakExtension.php

@@ -113,6 +113,7 @@ class TwigTweakExtension extends AbstractExtension {
       new TwigFilter('file_uri', [self::class, 'fileUriFilter']),
       new TwigFilter('file_url', [self::class, 'fileUrlFilter']),
       new TwigFilter('translation', [self::class, 'entityTranslation']),
+      new TwigFilter('cache_metadata', [self::class, 'CacheMetadata']),
     ];
 
     if (Settings::get('twig_tweak_enable_php_filter')) {
@@ -618,6 +619,19 @@ class TwigTweakExtension extends AbstractExtension {
     return \Drupal::service('entity.repository')->getTranslationFromContext($entity, $langcode);
   }
 
+  /**
+   * Extracts cache metadata from object or render array.
+   *
+   * @param \Drupal\Core\Cache\CacheableDependencyInterface|array $input
+   *   The cacheable object or render array.
+   *
+   * @return array
+   *   A render array with extracted cache metadata.
+   */
+  public static function cacheMetadata($input): array {
+    return \Drupal::service('twig_tweak.cache_metadata_extractor')->extractCacheMetadata($input);
+  }
+
   /**
    * Evaluates a string of PHP code.
    *

src/UrlExtractor.php

@@ -5,8 +5,11 @@ namespace Drupal\twig_tweak;
 use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Field\EntityReferenceFieldItemListInterface;
+use Drupal\Core\Field\FieldItemList;
 use Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem;
 use Drupal\file\FileInterface;
+use Drupal\link\LinkItemInterface;
+use Drupal\link\Plugin\Field\FieldType\LinkItem;
 use Drupal\media\MediaInterface;
 use Drupal\media\Plugin\media\Source\OEmbedInterface;
 
@@ -56,6 +59,12 @@ class UrlExtractor {
     elseif ($input instanceof EntityReferenceItem) {
       return $this->getUrlFromEntity($input->entity, $relative);
     }
+    elseif ($input instanceof LinkItemInterface) {
+      return $input->getUrl()->toString();
+    }
+    elseif ($input instanceof FieldItemList && $input->first() instanceof LinkItemInterface) {
+      return $input->first()->getUrl()->toString();
+    }
     return NULL;
   }
 

tests/src/Kernel/CacheMetadataExtractorTest.php

@@ -0,0 +1,91 @@
+<?php
+
+namespace Drupal\Tests\twig_tweak\Kernel;
+
+use Drupal\Core\Cache\CacheableMetadata;
+
+/**
+ * A test for Cache Metadata Extractor service.
+ *
+ * @group twig_tweak
+ */
+final class CacheMetadataExtractorTest extends AbstractExtractorTestCase {
+
+  /**
+   * Test callback.
+   */
+  public function testCacheMetadataExtractor(): void {
+
+    $extractor = $this->container->get('twig_tweak.cache_metadata_extractor');
+
+    // -- Object.
+    $input = new CacheableMetadata();
+    $input->setCacheMaxAge(5);
+    $input->setCacheContexts(['url', 'user.permissions']);
+    $input->setCacheTags(['node', 'node.view']);
+
+    $build = $extractor->extractCacheMetadata($input);
+    $expected_build['#cache'] = [
+      'contexts' => ['url', 'user.permissions'],
+      'tags' => ['node', 'node.view'],
+      'max-age' => 5,
+    ];
+    self::assertSame($expected_build, $build);
+
+    // -- Render array.
+    $input = [
+      'foo' => [
+        '#cache' => [
+          'tags' => ['foo', 'foo.view'],
+        ],
+        'bar' => [
+          0 => [
+            '#cache' => [
+              'tags' => ['bar-0'],
+            ],
+          ],
+          1 => [
+            '#cache' => [
+              'tags' => ['bar-1'],
+            ],
+          ],
+          '#cache' => [
+            'tags' => ['bar', 'bar.view'],
+            'contexts' => ['url.path'],
+            'max-age' => 10,
+          ],
+        ],
+      ],
+      '#cache' => [
+        'contexts' => ['url', 'user.permissions'],
+        'tags' => ['node', 'node.view'],
+        'max-age' => 20,
+      ],
+    ];
+    $build = $extractor->extractCacheMetadata($input);
+
+    $expected_build = [
+      '#cache' => [
+        'contexts' => ['url', 'url.path', 'user.permissions'],
+        'tags' => [
+          'bar',
+          'bar-0',
+          'bar-1',
+          'bar.view',
+          'foo',
+          'foo.view',
+          'node',
+          'node.view',
+        ],
+        'max-age' => 10,
+      ],
+    ];
+    self::assertSame($expected_build, $build);
+
+    // -- Wrong type.
+    self::expectErrorMessage('The input should be either instance of Drupal\Core\Cache\CacheableDependencyInterface or array. stdClass was given.');
+    /** @noinspection PhpParamsInspection */
+    $extractor->extractCacheMetadata(new \stdClass());
+  }
+
+}

twig_tweak.services.yml

@@ -39,3 +39,6 @@ services:
   twig_tweak.uri_extractor:
     class: Drupal\twig_tweak\UriExtractor
     arguments: ['@entity_type.manager']
+
+  twig_tweak.cache_metadata_extractor:
+    class: Drupal\twig_tweak\CacheMetadataExtractor