New in Symfony 7.4 Caching HTTP Client

Contributed by Jérôme Parmentier in #59576

The HttpClient component provides a caching feature to avoid repeated HTTP requests for the same content. Internally, it uses the HttpCache class from the HttpKernel component:

1
2
3
4
5
6
7
8
9
10

use Symfony\Component\HttpClient\CachingHttpClient;
use Symfony\Component\HttpClient\HttpClient;
use Symfony\Component\HttpKernel\HttpCache\Store;

$store = new Store('/path/to/cache/storage/');
$client = HttpClient::create();
$client = new CachingHttpClient($client, $store);

// this won't hit the network if the resource is already in the cache
$response = $client->request('GET', 'https://example.com/cacheable-resource');

In Symfony 7.4, we're revamping this feature to get rid of HttpCache, base caching on the Cache component, and make the implementation fully compliant with RFC 9111.

First, define a cache pool whose adapter is tag-aware:

1
2
3
4
5
6
7

# config/packages/framework.yaml
framework:
    cache:
        pools:
            example_cache_pool:
                adapter: cache.adapter.redis_tag_aware
                tags: true

Then, add the new caching option to your HTTP client to enable caching and use the given cache pool:

1
2
3
4
5
6
7
8
9
10
11
12
13

# config/packages/framework.yaml
framework:
    cache:
        pools:
            example_cache_pool:
                # ...

    http_client:
        scoped_clients:
            example.client:
                base_uri: 'https://example.com'
                caching:
                    cache_pool: example_cache_pool

That's all. Requests sent with that client are now cached according to RFC 9111. The caching option accepts two additional keys:

• shared: if true (the default value), the client uses a shared cache so cached responses can be reused across users;
• max_ttl: by default, responses are cached for as long as the TTL specified by the server. When this option is set, server-provided TTLs are capped to this value.