API: Director::handleRequest() is no longer static - use a Director service

NEW: Add HTMLMiddlewareAware trait to HTTPApplication, Director, and RequestHandler
NEW: Allow service specs to be passed to Director rules.

This refactor of the controller middlewares takes a service definition
approach rather than a static-method-and-config approach that Director
historically had.

The use of a trait for middleware means that the Middlewares array
property can be defined on RequestHandler, Director, and HTTPApplication
objects in the same way.

_config/requestprocessors.yml

@@ -1,16 +1,16 @@
 ---
 Name: requestprocessors
 ---
-SilverStripe\Control\Director:
-  middlewares:
-    TrustedProxyMiddleware: '%$SilverStripe\Control\TrustedProxyMiddleware'
-    AllowedHostsMiddleware: '%$SilverStripe\Control\AllowedHostsMiddleware'
-    SessionMiddleware: 'SilverStripe\Control\SessionMiddleware'
-    RequestProcessor: 'SilverStripe\Control\RequestProcessor'
-    FlushMiddleware: '%$SilverStripe\Control\FlushMiddleware'
-
-
 SilverStripe\Core\Injector\Injector:
+  SilverStripe\Control\Director:
+    properties:
+      Middlewares:
+        TrustedProxyMiddleware: '%$SilverStripe\Control\TrustedProxyMiddleware'
+        AllowedHostsMiddleware: '%$SilverStripe\Control\AllowedHostsMiddleware'
+        SessionMiddleware: '%$SilverStripe\Control\SessionMiddleware'
+        RequestProcessor: '%$SilverStripe\Control\RequestProcessor'
+        FlushMiddleware: '%$SilverStripe\Control\FlushMiddleware'
+
   SilverStripe\Control\AllowedHostsMiddleware:
     properties:
       AllowedHosts: "`SS_ALLOWED_HOSTS`"

_config/security.yml

@@ -19,10 +19,11 @@ SilverStripe\Core\Injector\Injector:
 ---
 Name: coresecurity
 ---
-SilverStripe\Control\Director:
-  middlewares:
-    - %$SilverStripe\Security\AuthenticationMiddleware
 SilverStripe\Core\Injector\Injector:
+  SilverStripe\Control\Director:
+    properties:
+      Middlewares:
+        - %$SilverStripe\Security\AuthenticationMiddleware
   SilverStripe\Security\AuthenticationMiddleware:
     properties:
       AuthenticationHandler: %$SilverStripe\Security\AuthenticationHandler

src/Control/Director.php

@@ -29,6 +29,7 @@ use SilverStripe\View\TemplateGlobalProvider;
 class Director implements TemplateGlobalProvider
 {
     use Configurable;
+    use HTTPMiddlewareAware;
 
     /**
      * Specifies this url is relative to the base.
@@ -132,7 +133,7 @@ class Director implements TemplateGlobalProvider
     ) {
         return static::mockRequest(
             function (HTTPRequest $request) {
-                return static::handleRequest($request);
+                return Injector::inst()->get(Director::class)->handleRequest($request);
             },
             $url,
             $postVars,
@@ -302,15 +303,12 @@ class Director implements TemplateGlobalProvider
      * @return HTTPResponse
      * @throws HTTPResponse_Exception
      */
-    public static function handleRequest(HTTPRequest $request)
+    public function handleRequest(HTTPRequest $request)
     {
         Injector::inst()->registerService($request, HTTPRequest::class);
 
         $rules = Director::config()->uninherited('rules');
 
-        // Get global middlewares
-        $middlewares = Director::config()->uninherited('middlewares') ?: [];
-
         // Default handler - mo URL rules matched, so return a 404 error.
         $handler = function () {
             return new HTTPResponse('No URL rule was matched', 404);
@@ -326,18 +324,6 @@ class Director implements TemplateGlobalProvider
                 }
             }
 
-            // Add controller-specific middlewares
-            if (isset($controllerOptions['Middlewares'])) {
-                // Force to array
-                if (!is_array($controllerOptions['Middlewares'])) {
-                    $controllerOptions['Middlewares'] = [$controllerOptions['Middlewares']];
-                }
-                $middlewares = array_merge($middlewares, $controllerOptions['Middlewares']);
-            }
-
-            // Remove null middlewares (may be included due to limitatons of config yml)
-            $middlewares = array_filter($middlewares);
-
             // Match pattern
             $arguments = $request->match($pattern, true);
             if ($arguments !== false) {
@@ -363,12 +349,25 @@ class Director implements TemplateGlobalProvider
 
                 // Find the controller name
                 $controller = $arguments['Controller'];
-                $controllerObj = Injector::inst()->create($controller);
+
+                // String = service name
+                if (is_string($controller)) {
+                    $controllerObj = Injector::inst()->get($controller);
+                // Array = service spec
+                } elseif (is_array($controller)) {
+                    $controllerObj = Injector::inst()->createFromSpec($controller);
+                } else {
+                    throw new \LogicException("Invalid Controller value '$controller'");
+                }
 
                 // Handler for calling a controller
                 $handler = function ($request) use ($controllerObj) {
                     try {
-                        return $controllerObj->handleRequest($request);
+                        // Apply the controller's middleware. We do this outside of handleRequest so that
+                        // subclasses of handleRequest will be called after the middlware processing
+                        return $controllerObj->callMiddleware($request, function ($request) use ($controllerObj) {
+                            return $controllerObj->handleRequest($request);
+                        });
                     } catch (HTTPResponse_Exception $responseException) {
                         return $responseException->getResponse();
                     }
@@ -377,12 +376,8 @@ class Director implements TemplateGlobalProvider
             }
         }
 
-        // Call the handler with the given middlewares
-        $response = self::callWithMiddlewares(
-            $request,
-            $middlewares,
-            $handler
-        );
+        // Call the handler with the configured middlewares
+        $response = $this->callMiddleware($request, $handler);
 
         // Note that if a different request was previously registered, this will now be lost
         // In these cases it's better to use Kernel::nest() prior to kicking off a nested request

src/Control/HTTPApplication.php

@@ -3,6 +3,7 @@
 namespace SilverStripe\Control;
 
 use SilverStripe\Core\Application;
+use SilverStripe\Core\Injector\Injector;
 use SilverStripe\Control\HTTPMiddleware;
 use SilverStripe\Core\Kernel;
 
@@ -11,10 +12,8 @@ use SilverStripe\Core\Kernel;
  */
 class HTTPApplication implements Application
 {
-    /**
-     * @var HTTPMiddleware[]
-     */
-    protected $middlewares = [];
+
+    use HTTPMiddlewareAware;
 
     /**
      * @var Kernel
@@ -26,54 +25,6 @@ class HTTPApplication implements Application
         $this->kernel = $kernel;
     }
 
-    /**
-     * @return HTTPMiddleware[]
-     */
-    public function getMiddlewares()
-    {
-        return $this->middlewares;
-    }
-
-    /**
-     * @param HTTPMiddleware[] $middlewares
-     * @return $this
-     */
-    public function setMiddlewares($middlewares)
-    {
-        $this->middlewares = $middlewares;
-        return $this;
-    }
-
-    /**
-     * @param HTTPMiddleware $middleware
-     * @return $this
-     */
-    public function addMiddleware(HTTPMiddleware $middleware)
-    {
-        $this->middlewares[] = $middleware;
-        return $this;
-    }
-
-    /**
-     * Call middleware
-     *
-     * @param HTTPRequest $request
-     * @param callable $last Last config to call
-     * @return HTTPResponse
-     */
-    protected function callMiddleware(HTTPRequest $request, $last)
-    {
-        // Reverse middlewares
-        $next = $last;
-        /** @var HTTPMiddleware $middleware */
-        foreach (array_reverse($this->getMiddlewares()) as $middleware) {
-            $next = function ($request) use ($middleware, $next) {
-                return $middleware->process($request, $next);
-            };
-        }
-        return call_user_func($next, $request);
-    }
-
     /**
      * Get the kernel for this application
      *
@@ -96,7 +47,7 @@ class HTTPApplication implements Application
 
         // Ensure boot is invoked
         return $this->execute($request, function (HTTPRequest $request) {
-            return Director::handleRequest($request);
+            return Injector::inst()->get(Director::class)->handleRequest($request);
         }, $flush);
     }
 

src/Control/HTTPMiddlewareAware.php

@@ -0,0 +1,64 @@
+<?php
+
+namespace SilverStripe\Control;
+
+/**
+ * Adds middleware support to an object.
+ * Provides a Middlewares property and a callMiddleware() callback
+ */
+trait HTTPMiddlewareAware
+{
+    /**
+     * @var HTTPMiddleware[]
+     */
+    protected $middlewares = [];
+
+    /**
+     * @return HTTPMiddleware[]
+     */
+    public function getMiddlewares()
+    {
+        return $this->middlewares;
+    }
+
+    /**
+     * @param HTTPMiddleware[] $middlewares
+     * @return $this
+     */
+    public function setMiddlewares($middlewares)
+    {
+        // Allow nulls in the middlewares array to deal with limitations of yml config
+        $this->middlewares = array_filter((array)$middlewares);
+        return $this;
+    }
+
+    /**
+     * @param HTTPMiddleware $middleware
+     * @return $this
+     */
+    public function addMiddleware(HTTPMiddleware $middleware)
+    {
+        $this->middlewares[] = $middleware;
+        return $this;
+    }
+
+    /**
+     * Call middleware
+     *
+     * @param $request The request to pass to the middlewares and callback
+     * @param $last The callback to call after all middlewares
+     * @return HTTPResponse
+     */
+    public function callMiddleware(HTTPRequest $request, callable $last)
+    {
+        // Reverse middlewares
+        $next = $last;
+        /** @var HTTPMiddleware $middleware */
+        foreach (array_reverse($this->getMiddlewares()) as $middleware) {
+            $next = function ($request) use ($middleware, $next) {
+                return $middleware->process($request, $next);
+            };
+        }
+        return $next($request);
+    }
+}

src/Control/RequestHandler.php

@@ -46,6 +46,9 @@ use BadMethodCallException;
  */
 class RequestHandler extends ViewableData
 {
+
+    use HTTPMiddlewareAware;
+
     /**
      * Optional url_segment for this request handler
      *