TYPO3 Core

Hey Mati,

thanks for your feedback. And yes, this is the right place to ask such questions!

PSR-15 middlewares have been introduced in TYPO3 v9 in order to migrate away from hooks to a new system that allows to modify request + response at any given time, as you expect.

PSR-14 events have been introduced in TYPO3 v10 to slowly move away from hooks and especially SignalSlots (from Extbase) into a unified and interchange-able way across PHP frameworks and projects.

There are still a lot of hooks in TYPO3, mostly because we don't replace them "because we can" but adding new ways to modify the core behavior should be done through PSR-14 or PSR-15. PSR-15 allows to create a middleware (= and extend TYPO3's behavior) explicitly at a frontend request / response for the reason you mention. Why? Because you can avoid a lot of code execution if you don't need to. This is the right spot, and you are free to place your custom code before or after any middleware.

Hooks + PSR-14 are used across the whole system (PSR-14 more and more in favor hooks), also e.g. in the persistence layer, whereas PSR-15 can modify a request or response only.

However, adding a PSR-14 event into a PSR-15 middleware provided by TYPO3 Core actually does the opposite of giving the user more flexibility. We actually had this issue when introducing new hooks: For some people it's just one step to early / late to do their custom implementation. With middlewares, the choice is yours, and especially if you want to switch to static caching, you can choose the place where you "want to hook into" yourself.

If you want to hook into the moment once the fully created page is stored in cache, the hook you mentioned is totally fine. and "hooking into the frontend rendering" concept via a middleware is totally legit and takes less code than registering a PSR-14 event IMHO.

Does that answer your question?

Cool. Thanks for letting me know!