Contributed by
Nicolas Grekas
in #19047.
In Symfony 3.1 we added a new Cache component that was a strict implementation of the PSR-6: Caching Interface standard. In Symfony 3.2 we decided to improve the cache with some features not defined by the standard.
The first new feature is the tag-based invalidation to create tagged caches. Imagine that your application is an e-commerce application that stores users' reviews in the cache. When saving those reviews, you can now associate tags to them:
1 2 3 4 5 6 7 8 9 | useSymfony\Component\Cache\Adapter\FilesystemAdapter;$cache=newFilesystemAdapter();$review=$cache->getItem('reviews-'.$reviewId);$review->set('...');$review->tag(['reviews','products','product-'.$productId]);$cache->save($review); |
The cached review is associated with three different tags that can be used to invalidate related items:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | // the HTML structure of reviews has changed:// invalidate all reviews$cache->invalidateTags('reviews');// a special sale is enabled in the store:// invalidate anything related to products$cache->invalidateTags('products');// the data of the product #123 has changed:// invalidate anything related to that product$cache->invalidateTags('product-123');// a major store update is being deployed:// invalidate all the information related to products and reviews$cache->invalidateTags(['products','reviews']);// after invalidating any of the previous tags, the item is no longer// available in the cache:$cache->getItem('reviews-'.$reviewId)->isHit();// returns false |
The Cache component now defines a TagAwareAdapterInterface to add tag-based
invalidation to your own cache adapters and TaggedCacheItemInterface to
allow tagging cache items. In addition, it includes a TagAwareRedisAdapter
to enable tag-based invalidation when using Redis.