Add a flag to allow an opt-out from AddTagsListener

[domgraziano]

Q	A
Branch?	main for features
Tickets	#3168
License	MIT
Doc PR	api-platform/docs#...

I noticed that at each request this ApiPlatform\Core\HttpCache\EventListener\AddTagsListener adds Cache-Tags just before returning the response. For large interconnected entities this can have unexpected consequences and it should really be an opt-in listener in my mind. In my case for example I have https://linkerd.io/ limiting infra service communication headers to 12k. On each get because of this listener I have bigger than 12k headers for specific "big" linked resources ... this happens on GET(s) too! For backward compatibility though I added a flag so that by default is turned on but can be turned off easily under http_cache config.

[alanpoulain]

You can already turn off the invalidation system:

api_platform:
    http_cache:
        invalidation: false

[domgraziano]

You can already turn off the invalidation system:

api_platform:
    http_cache:
        invalidation: false

thank you! I was aware of that, this is an attempt instead to opt-out from the added cache tags in the response headers, leaving the invalidation enabled without causing bkwrd incompatibility.
Let's say that I want to change the mechanism of how cache tags are stored in the headers (see #3168) sometimes are just too big and I want compress them (for example). So I would not need that subscriber adding all the uris to my headers.

[alanpoulain]

So you want to keep the Varnish purger but not the Cache-Tags header?
Personally I find it too much fine-grained. Why not removing yourself it in your DependencyInjection?

[domgraziano]

So you want to keep the Varnish purger but not the Cache-Tags header?
Personally I find it too much fine-grained. Why not removing yourself it in your DependencyInjection?

Ok, I see what you mean ... closing this then