Merge pull request #13 from tbreuss/develop

Cleaner & better middleware implementation

src/Application.php

@@ -7,10 +7,9 @@
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\MiddlewareInterface;
-use Tebe\HttpFactory\HttpFactory;
 use Tebe\Pvc\Exception\SystemException;
-use Tebe\Pvc\Middleware\MiddlewareDispatcher;
-use Tebe\Pvc\Middleware\RouterMiddleware;
+use Tebe\Pvc\Middleware\MiddlewarePipe;
+use Tebe\Pvc\Middleware\RequestHandler;
 
 class Application
 {
@@ -175,20 +174,10 @@ public function run(): void
         $view = new View($viewsPath);
         $this->setView($view);
 
-        $middlewares = array_merge(
-            $this->middlewares,
-            [new RouterMiddleware($this->getView(), $this->getConfig()->get('controllersPath'))]
-        );
-
-        $middlewareDispatcher = new MiddlewareDispatcher(
-            $middlewares,
-            function () {
-                return (new HttpFactory)->createResponse(200);
-            }
-        );
-
+        $pipe = MiddlewarePipe::create($this->middlewares);
         $request = $this->getRequest();
-        $response = $middlewareDispatcher->handle($request);
+        $requestHandler = new RequestHandler($view, $this->getConfig()->get('controllersPath'));
+        $response = $pipe->process($request, $requestHandler);
 
         $this->emit($response);
     }

src/Middleware/MiddlewarePipe.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace Tebe\Pvc\Middleware;
+
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+
+class MiddlewarePipe implements MiddlewareInterface
+{
+    /**
+     * @var ServerMiddlewareInterface[]
+     */
+    private $middlewares = [];
+
+    private function __construct()
+    {
+    }
+
+    /**
+     * @param MiddlewareInterface[] $middlewares FIFO array of middlewares
+     * @return self
+     */
+    public static function create(array $middlewares = []): self
+    {
+        $pipe = new self();
+        foreach ($middlewares as $middleware) {
+            $pipe = $pipe->add($middleware);
+        }
+        return $pipe;
+    }
+
+    /**
+     * @param ServerRequestInterface $request
+     * @param RequestHandlerInterface $requestHandler
+     * @return ResponseInterface
+     */
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $requestHandler): ResponseInterface
+    {
+        if (empty($this->middlewares)) {
+            return $requestHandler->handle($request);
+        }
+        $stack = MiddlewareStack::create($requestHandler, array_reverse($this->middlewares));
+        return $stack->handle($request);
+    }
+
+    /**
+     * Creates a new pipe with the given middleware connected.
+     *
+     * @param MiddlewareInterface $middleware
+     * @return self
+     */
+    public function add(MiddlewareInterface $middleware): self
+    {
+        $pipe = clone $this;
+        array_push($pipe->middlewares, $middleware);
+        return $pipe;
+    }
+}

src/Middleware/MiddlewareStack.php

@@ -0,0 +1,87 @@
+<?php
+
+namespace Tebe\Pvc\Middleware;
+
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+
+class MiddlewareStack implements RequestHandlerInterface
+{
+    /**
+     * @var RequestHandlerInterface
+     */
+    private $requestHandler;
+
+    /**
+     * @var MiddlewareInterface[]
+     */
+    private $middlewares = [];
+
+    /**
+     * @param RequestHandlerInterface $requestHandler
+     */
+    private function __construct(RequestHandlerInterface $requestHandler)
+    {
+        $this->requestHandler = $requestHandler;
+    }
+
+    /**
+     * @param RequestHandlerInterface $requestHandler
+     * @param MiddlewareInterface[] $middlewares LIFO array of middlewares
+     * @return self
+     */
+    public static function create(RequestHandlerInterface $requestHandler, array $middlewares = []): self
+    {
+        $stack = new self($requestHandler);
+        foreach ($middlewares as $middleware) {
+            $stack = $stack->push($middleware);
+        }
+        return $stack;
+    }
+
+    /**
+     * @param ServerRequestInterface $request
+     * @return ResponseInterface
+     */
+    public function handle(ServerRequestInterface $request): ResponseInterface
+    {
+        $next = $this->peek();
+        if (null === $next) {
+            return $this->requestHandler->handle($request);
+        }
+        return $next->process($request, $this->pop());
+    }
+
+    /**
+     * Creates a new stack with the given middleware pushed.
+     *
+     * @param MiddlewareInterface $middleware
+     * @return self
+     */
+    public function push(MiddlewareInterface $middleware): self
+    {
+        $stack = clone $this;
+        array_unshift($stack->middlewares, $middleware);
+        return $stack;
+    }
+
+    /**
+     * @return MiddlewareInterface|null
+     */
+    private function peek()
+    {
+        return reset($this->middlewares) ?: null;
+    }
+
+    /**
+     * @return self
+     */
+    private function pop(): self
+    {
+        $stack = clone $this;
+        array_shift($stack->middlewares);
+        return $stack;
+    }
+}

src/Middleware/RouterMiddleware.php → src/Middleware/RequestHandler.php

@@ -6,15 +6,15 @@
 
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
-use Psr\Http\Server\MiddlewareInterface;
 use Psr\Http\Server\RequestHandlerInterface;
+use Tebe\HttpFactory\HttpFactory;
 use Tebe\Pvc\Controller;
 use Tebe\Pvc\ErrorController;
 use Tebe\Pvc\Exception\HttpException;
 use Tebe\Pvc\Exception\SystemException;
 use Tebe\Pvc\View;
 
-class RouterMiddleware implements MiddlewareInterface
+class RequestHandler implements RequestHandlerInterface
 {
     /**
      * @var View
@@ -35,6 +35,7 @@ class RouterMiddleware implements MiddlewareInterface
      * RouterMiddleware constructor.
      * @param View $view
      * @param string $controllersPath
+     * @throws SystemException
      */
     public function __construct(View $view, string $controllersPath)
     {
@@ -43,14 +44,12 @@ public function __construct(View $view, string $controllersPath)
     }
 
     /**
-     * @param ServerRequestInterface $request
-     * @param RequestHandlerInterface $handler
-     * @return ResponseInterface
+     * Handle the request and return a response.
      */
-    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    public function handle(ServerRequestInterface $request): ResponseInterface
     {
         $this->request = $request;
-        $response = $handler->handle($request);
+        $response = (new HttpFactory())->createResponse();
         $pathInfo = $this->getPathInfo();
 
         try {
@@ -129,6 +128,7 @@ private function executeAction(Controller $controller): string
      * @param Controller $controller
      * @param string $methodName
      * @return array
+     * @throws \ReflectionException
      */
     private function getHttpGetVars(Controller $controller, string $methodName): array
     {