Drupal Caching
Always add cache metadata. Missing cache metadata causes stale content.
Cache Metadata in Render Arrays
$build['content'] = [
'#markup' => $output,
'#cache' => [
'tags' => ['node:' . $node->id(), 'node_list'],
'contexts' => ['user.permissions', 'url.query_args'],
'max-age' => Cache::PERMANENT,
],
];
Cache Tags
| Tag | Invalidated when |
|---|
node:{nid} | Node {nid} is saved/deleted |
node_list | Any node is created or deleted |
user:{uid} | User {uid} is saved |
taxonomy_term:{tid} | Term {tid} is saved |
config:{name} | Config object {name} is saved |
Cache Contexts
| Context | Varies by |
|---|
user.permissions | User's permissions (prefer over user) |
user.roles | User's roles |
url.path | URL path |
url.query_args | Query parameters |
languages | Current language |
Reading/Writing Cache
$cached = $this->cacheBackend->get('my_module:my_key');
if ($cached !== FALSE) {
return $cached->data;
}
$this->cacheBackend->set('my_module:my_key', $data, Cache::PERMANENT, ['node_list']);
$this->cacheBackend->set('my_module:my_key', $data, \Drupal::time()->getRequestTime() + 3600, ['node_list']);
$this->cacheBackend->delete('my_module:my_key');
Cache::invalidateTags(['node:123', 'node_list']);
Inject Cache Service
use Drupal\Core\Cache\CacheBackendInterface;
public function __construct(
private readonly CacheBackendInterface $cacheBackend,
) {}
# services.yml
my_module.my_service:
arguments: ['@cache.default']
CacheableDependencyInterface
$build['#cache']['tags'] = Cache::mergeTags(
$build['#cache']['tags'] ?? [],
$node->getCacheTags()
);
