Middleware

Middleware are the methods invoked before invoke specific mapping. They can return errors, give data into mapping, validate and what else you like.

Before route annotation

Before route annotation can annotate classes and methods.

• If annotates class then every request into that controller must successfully go over by everyone middleware method in the stack.
• If annotates mapping method only request into that specific route must successfully go over by all methods in the stack.

Before route syntax:

// Every single route must pass `Authenticator::requiresAuthentication` method.
#[RestController]
#[BeforeRoute(["Authenticator", "requiresAuthentication"])]
class UserAuthController {
    #[Autowired]
    private UserService $userService;

    // That route must pass two methods: `Authenticator::requiresAuthentication` and `Authenticator::requiresAdmin`.
    #[GetMapping("/users")]
    #[BeforeRoute(["Authenticator", "requiresAdmin"])]
    public function adminRoute() {
        return $this->userService->getAll();
    }
}

Next class

Middleware to pass successfully must return Next instance. Every else data returned by middleware method will reject requests.

// ...
public function requiresAuthentication(HttpRequest $request, HttpResponse $response): Next|null {
  // success
  if (!$request->locals['user']->isAdmin()) {
    return null;
  }

  // reject
  return new Next();
}
// ...

Move data between middlewares

To retrieve data from previous middlewares you can store and get data from HttpRequest locals property. In previous example previous methods (Authenticator::requiresAuthentication) sets user into locals and requiresAuthentication methods has access to that data and can check is logged-in user is admin.

Get data from middleware in mapping

To get data from middleware you can HttpRequest and locals array like between middleware or use RequestStorageItem annotation.

#[GetMapping("/logged")]
public function getLoggedInUser(HttpRequest $request) {
  return $request->locals['user'];
}

Or

#[GetMapping("/logged")]
public function getLoggedInUser(#[RequestStorageItem(name: "user")] User $user) {
  return $user;
}

Both methods do the same job which you like is up to you.