From 01c1e137f752603cba424b7c0db2db9ed334b295 Mon Sep 17 00:00:00 2001
From: Philipp <admin@philipp.info>
Date: Sun, 2 Jan 2022 20:25:32 +0100
Subject: [PATCH] Add OPTIONS endpoint

---
 src/App/Router.php             | 12 ++++--------
 src/BaseModule.php             | 15 +++++++++++++++
 src/Module/Special/Options.php | 16 ++++++++++++++++
 3 files changed, 35 insertions(+), 8 deletions(-)
 create mode 100644 src/Module/Special/Options.php

diff --git a/src/App/Router.php b/src/App/Router.php
index bbc3dd348e..c2887b1059 100644
--- a/src/App/Router.php
+++ b/src/App/Router.php
@@ -37,9 +37,9 @@ use Friendica\Core\Lock\Capability\ICanLock;
 use Friendica\LegacyModule;
 use Friendica\Module\HTTPException\MethodNotAllowed;
 use Friendica\Module\HTTPException\PageNotFound;
+use Friendica\Module\Special\Options;
 use Friendica\Network\HTTPException;
 use Friendica\Network\HTTPException\MethodNotAllowedException;
-use Friendica\Network\HTTPException\NoContentException;
 use Friendica\Network\HTTPException\NotFoundException;
 use Psr\Log\LoggerInterface;
 
@@ -141,13 +141,6 @@ class Router
 
 		$httpMethod = $this->server['REQUEST_METHOD'] ?? self::GET;
 
-		// @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/OPTIONS
-		// @todo Check allowed methods per requested path
-		if ($httpMethod === static::OPTIONS) {
-			header('Allow: ' . implode(',', Router::ALLOWED_METHODS));
-			throw new NoContentException();
-		}
-
 		$this->httpMethod = in_array($httpMethod, self::ALLOWED_METHODS) ? $httpMethod : self::GET;
 
 		$this->routeCollector = isset($routeCollector) ?
@@ -284,6 +277,9 @@ class Router
 			$this->parameters = $routeInfo[2];
 		} elseif ($routeInfo[0] === Dispatcher::METHOD_NOT_ALLOWED) {
 			throw new HTTPException\MethodNotAllowedException($this->l10n->t('Method not allowed for this module. Allowed method(s): %s', implode(', ', $routeInfo[1])));
+		} elseif ($this->httpMethod === static::OPTIONS) {
+			// Default response for HTTP OPTIONS requests in case there is no special treatment
+			$moduleClass = Options::class;
 		} else {
 			throw new HTTPException\NotFoundException($this->l10n->t('Page not found.'));
 		}
diff --git a/src/BaseModule.php b/src/BaseModule.php
index 08efff3d78..4fbf39cf71 100644
--- a/src/BaseModule.php
+++ b/src/BaseModule.php
@@ -173,6 +173,18 @@ abstract class BaseModule implements ICanHandleRequests
 	{
 	}
 
+	/**
+	 * Module OPTIONS method to process submitted data
+	 *
+	 * Extend this method if the module is supposed to process OPTIONS requests.
+	 * Doesn't display any content
+	 *
+	 * @param string[] $request The $_REQUEST content
+	 */
+	protected function options(array $request = [])
+	{
+	}
+
 	/**
 	 * {@inheritDoc}
 	 */
@@ -225,6 +237,9 @@ abstract class BaseModule implements ICanHandleRequests
 			case Router::PUT:
 				$this->put($request);
 				break;
+			case Router::OPTIONS:
+				$this->options($request);
+				break;
 		}
 
 		$timestamp = microtime(true);
diff --git a/src/Module/Special/Options.php b/src/Module/Special/Options.php
new file mode 100644
index 0000000000..36bbe4fb13
--- /dev/null
+++ b/src/Module/Special/Options.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Friendica\Module\Special;
+
+use Friendica\App\Router;
+use Friendica\BaseModule;
+
+class Options extends BaseModule
+{
+	protected function options(array $request = [])
+	{
+		// @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/OPTIONS
+		$this->response->setHeader('Allow', implode(',', Router::ALLOWED_METHODS));
+		$this->response->setHeader(($this->server['SERVER_PROTOCOL'] ?? 'HTTP/1.1') . ' 204 No Content');
+	}
+}