I would love to see an interface like your ControllerInterface, but I believe most developers associate the word Controller with MVC etc. hence I believe the concerns about framework-territory are partially justified, the name would raise unrelated expectations.
In my opinion, "takes a request and returns a response" is the broadest > definition you can give and still imply that it's even an HTTP application. Well, in that case I would suggest (similar to Symfony\Component\HttpKernel\HttpKernelInterface <https://github.com/symfony/symfony/blob/master/src/Symfony/Component/HttpKernel/HttpKernelInterface.php> ): - [Server]RequestHandlerInterface - [Server]RequestDispatcherInterface - [Server]RequestProcessorInterface All of these are not burdened terms like Controller and the names work nicely in conjunction with concrete classes, e.g.: class FooController implements RequestHandlerInterface {…} class DefaultHandler implements RequestHandlerInterface {…} The real benefit I see with such an interface is the absence of a framework – we do not need a MVC framework or a middleware stack/pipe/dispatcher to process a request, only a ServerRequestInterface instance is needed. Furthermore many libraries already support the signature of the interface method, which shows me that such an interface would not be too framework-specific, e.g. Aura.Router: $ctrl = new Controller(); // add a route $map->get('blog.read', '/blog/{id}', [$ctrl, 'dispatch']); // or with an __invoke interface: $map->get('blog.read', '/blog/{id}', $ctrl); About the FilterInterface idea: honestly I would not bundle it with ControllerInterface. I believe, history has taught us that this is a bad idea, it only causes delays. Bests, Michael Mayer Am Dienstag, 24. Januar 2017 17:45:56 UTC+1 schrieb Rasmus Schultz: > > Any interest in a simple PSR for Controllers? > > What I'm suggesting here is something that is extremely abstract and > generic - something that builds upon PSR-7. > > The interface itself could be as simple as this: > > interface ControllerInterface > { > public function dispatch(ServerRequestInterface $request): > ResponseInterface; > } > > To contrast this with the middleware-interface of PSR-15, "middleware" is > a component that shares control with other middleware-components, e.g. > *may* do something to a request, or might just pass - as opposed to a > "controller", which is a component that *must* process the request and > create a response, so this would be something to which routing (of any > kind) has determined that, for the given request, this *is* the component > responsible for processing. > > This would work for front-controllers (such as a middleware-stack based on > PSR-15) as well as for any other types front-controllers, e.g. anything you > might use in a catch-all "index.php" as the top layer of request routing. > > It would work for any kind of action-controller as well, e.g. using > abstract base-classes to implement specific dispatch-strategies, and > assuming any other dependencies would be provided via dependency-injection > - which would be outside the scope of this PSR, but you can imagine > abstract base-classes implementing different dispatch-strategies, such as > dynamically mapping GET or POST params against argument-names of a run() > method, providing integration with a DI container, etc. > > We currently use such a strategy and an identical ControllerInterface at > work, and it's been a real success. Our default base-class, for example, > detects a JSON object body being posted, decodes it and maps > object-properties against arguments - and for form-posts, it checks for > scalar type-hints of the run-method and performs int, float and bool > conversions, array and string type-checks, etc. > > We enjoy the security of being able to replace our controller-pattern > completely without breaking compatibility with existing controllers, and > the freedom of being able to implement highly specialized controllers (such > as a controller that resizes images) without using a base-class at all. > > This pattern and interface makes any controller-implementation compatible > with any router capable of resolving a request to a ControllerInterface > instance, or perhaps a class-name for integration with a DI container. (In > our stack, that means the router is responsible solely for determining a > class-name - we use a class-per-action pattern, but a router could of > course also resolve to an action-method name and provide that to a > controller-implementation via constructor-injection - as with most patterns > this simple, your imagination seems to be the limit.) > > Basically any router that can resolve a path to a string and HTTP-method > can interop with this - micro-frameworks that go beyond just resolving the > request to a value (e.g. creates or runs controllers) would likely be able > to interop with this in other ways. > > This is one part of the story. > > The other part is about filters - often there is a need to secure a > controller, accept or reject certain content-types, apply caching, or do > some other form of filtering before/after actually running the controller. > > That sounds a lot like middleware - in fact, a lot of middleware > components would be immediately useful if a controller could simply apply > them as filters. So there is no need to invent a new concept here, PSR-15 > would do the job, we only need to define how filters get created. > > The following simple interface would do that: > > interface FilterInterface > { > /** > * @return ServerMiddlewareInterface[] > */ > public function getFilters(): array; > } > > This could be part of the same PSR or separate. > > Now a controller can (optionally) implement this and use it to declare > controller-specific middleware as filters - e.g. return [new > CacheMiddleware(), new PostFilter()] might apply some caching-headers and a > POST-method restriction. > > Whatever is returned by this method gets run before the controller itself > is dispatched - in other words, to the last middleware-component > (PostFilter in this example) the delegate that gets passed does not > delegate to a middleware-component but to the controller itself. > > How precisely the filter-middleware gets dispatched is outside the scope > of this PSR - it's up to the controller base-class or framework, wherever > you choose to place this responsibility. An abstract controller base-class > could support FilterInterface internally, or it could be done in a router, > middleware or micro-framework. > > We haven't attempted the filter pattern in our own stack yet, so I can't > say for sure if this would work out as dreamy as I think it would - but I > think we eventually will try it, as there's a very real need and many > practical use-cases. > > As for the controller pattern, it's sort of a no-brainer - it's totally > trivial, and it just works. > > Well, I figured I'd put the idea out there, as it has already had great > value for us, in terms of decoupling and separating concerns like routing > and middleware from controllers and dispatch-strategies. > > I figure it's worth sharing the idea :-) > > Thoughts? > > - Rasmus > > -- You received this message because you are subscribed to the Google Groups "PHP Framework Interoperability Group" group. 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