add cors middleware

Author: ylebre

solid/lib/AppInfo/Application.php

@@ -11,6 +11,7 @@
 
 use OCA\Solid\Service\UserService;
 use OCA\Solid\WellKnown\OpenIdConfigurationHandler;
+use OCA\Solid\Middleware\SolidCorsMiddleware;
 
 use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
@@ -53,6 +54,12 @@ public function register(IRegistrationContext $context): void {
 		$context->registerService('User', function($c) {
 			return $c->query('UserSession')->getUser();
 		});
+
+		$context->registerService('SolidCorsMiddleware', function($c) {
+		        return new SolidCorsMiddleware();
+		});
+
+		$context->registerMiddleware('SolidCorsMiddleware');
 	}
 
 	public function boot(IBootContext $context): void {

solid/lib/Middleware/SolidCorsMiddleware.php

@@ -0,0 +1,23 @@
+<?php
+    namespace OCA\Solid\Middleware;
+
+    use \OCP\AppFramework\Middleware;
+    use \OCP\IRequest;
+
+    class SolidCorsMiddleware extends Middleware {
+        public function afterController($controller, $methodName, IResponse $response) {
+            $corsMethods="GET, PUT, POST, OPTIONS, DELETE, PATCH";
+            $corsAllowedHeaders="*, allow, accept, authorization, content-type, dpop, slug";
+            $corsMaxAge=1728000;
+            $corsExposeHeaders="Authorization, User, Location, Link, Vary, Last-Modified, ETag, Accept-Patch, Accept-Post, Updates-Via, Allow, WAC-Allow, Content-Length, WWW-Authenticate, MS-Author-Via";
+            $corsAllowCredentials=true;
+            
+            $response->addHeader('Access-Control-Allow-Origin', $corsAllowOrigin);
+            $response->addHeader('Access-Control-Allow-Methods', $corsMethods);
+            $response->addHeader('Access-Control-Allow-Headers', $corsAllowedHeaders);
+            $response->addHeader('Access-Control-Max-Age', (string)$corsMaxAge);
+            $response->addHeader('Access-Control-Allow-Credentials', $corsAllowCredentials);
+            $response->addHeader('Access-Control-Expose-Headers', $corsExposeHeaders);
+            $response->addHeader('Accept-Patch', 'text/n3');
+        }
+    }