Allow PSR-6 caching adapter

[rvanlaak]

We moved away from the DoctrineCacheBundle lately and use the PSR-6 CacheBundle now. Would be great if this bundle could support both.

@Nyholm what would it take to make this bundle compatible? Or should https://github.com/asm89/twig-cache-extension be changed for this?

[Nyholm]

Since the asm89/twig-cache-extension library has wrapped the Doctrine cache within DoctrineCacheAdapter you could quite easily start using PSR-6 instead of Doctrine. You just need to make sure to verify the type of the twig_cache.service. If it is PSR-6 then do not change, if it is Doctrine use the DoctrineAdapter to make it PRS-6 (see below.) And that is all the change you need to do.

But ideally, you could remove the extra abstraction layer and relay on the PSR-6 interfaces. Ie removing Asm89\Twig\CacheExtension\CacheProvider\DoctrineCacheAdapter and Asm89\Twig\CacheExtension\CacheProviderInterface. That will make the library smaller and easier to reuse.

---

To make it easy for users to upgrade you should look into the DoctrineAdapter. With some minor work in a compiler pass you can be PSR-6 compatible without the user need to update their configuration.

// Just to give an idea. This code needs some work..
$pool = $this->container->get('twig_cache.service');
if ($pool instanceof \Doctrine\Common\Cache\Cache) {
  $pool = new DoctrineCachePool($doctrineCache);
}
if (!$pool instanceof CacheItemPoolInterface) {
  throw new \Exception();
}

[rvanlaak]

Made https://github.com/asm89/twig-cache-extension/pull/32 which introduces the PsrCacheAdapter which makes it even easier to migrate because it allows injection of a PSR-6 CacheItemPoolInterface that still extends the bundle's CacheProviderInterface.

Next to the cache_adapter configuration I already had in place, adding one extra configuration line was enough:

# parameters.yml
twig_cache.adapter.class: Asm89\Twig\CacheExtension\CacheProvider\PsrCacheAdapter

Because of the Symfony CacheBundle, after that I was able to set the cache.provider.mycache service.

# config.yml
cache_adapter:
    providers:
        twig_apcu:
            factory: 'cache.factory.apcu'

twig_cache:
    service: cache.provider.twig_apcu

After the PR is accepted, I'll add a PR here too for the documentation change.

Edit: https://github.com/EmanueleMinotto/TwigCacheBundle/pull/14 is created but errors because other PR was not accepted yet

[rvanlaak]

Adapter was merged, you can do a composer update and use the new configuration as mentioned above.