Issue #3069526 by e0ipso: Make the _api_proxy_uri parameter name configurable

api_proxy.services.yml

+parameters:
+  api_proxy.uri_param_name: _api_proxy_uri
 services:
   Drupal\api_proxy\Plugin\HttpApiPluginManager:
     autowire: true
@@ -11,5 +13,6 @@ services:
     arguments:
       - '@router.route_provider'
       - '@Drupal\api_proxy\EventSubscriber\OptionsRequestSubscriber.inner'
+      - '%api_proxy.uri_param_name%'
     tags:
       - { name: event_subscriber }

src/Controller/Forwarder.php

@@ -8,6 +8,7 @@ use Drupal\Core\Cache\CacheableResponse;
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\Core\Http\Exception\CacheableAccessDeniedHttpException;
 use Drupal\Core\Http\Exception\CacheableBadRequestHttpException;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 
@@ -16,7 +17,29 @@ use Symfony\Component\HttpFoundation\Response;
  */
 final class Forwarder extends ControllerBase {
 
-  const QUERY_PARAM_URI = '_api_proxy_uri';
+  /**
+   * The name of the query string parameter containing the URI.
+   *
+   * @param string
+   */
+  private $uriParamName;
+
+  /**
+   * Forwarder constructor.
+   *
+   * @param string $uri_param_name
+   *   The name of the query string parameter containing the URI.
+   */
+  public function __construct(string $uri_param_name) {
+    $this->uriParamName = $uri_param_name;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static($container->getParameter('api_proxy.uri_param_name'));
+  }
 
   /**
    * Forwards incoming requests to the connected API.
@@ -33,7 +56,7 @@ final class Forwarder extends ControllerBase {
     // TODO: This belongs to the routing system.
     $account = $this->currentUser();
     $cache_contexts = [
-      'url.query_args:' . Forwarder::QUERY_PARAM_URI,
+      'url.query_args:' . $this->uriParamName,
       'headers:Origin',
       'user.permissions',
     ];
@@ -46,11 +69,11 @@ final class Forwarder extends ControllerBase {
         'The current user does not have access to this proxy'
       );
     }
-    $third_party_uri = $request->query->get(static::QUERY_PARAM_URI);
+    $third_party_uri = $request->query->get($this->uriParamName);
     if (empty($third_party_uri)) {
       throw new CacheableBadRequestHttpException(
         $cacheability,
-        sprintf('Unable to find a valid URI in the %s query parameter.', static::QUERY_PARAM_URI)
+        sprintf('Unable to find a valid URI in the %s query parameter.', $this->uriParamName)
       );
     }
     $response = $api_proxy->forward($request, $third_party_uri);

src/EventSubscriber/OptionsRequestSubscriber.php

@@ -33,6 +33,13 @@ class OptionsRequestSubscriber implements EventSubscriberInterface {
    */
   protected $subject;
 
+  /**
+   * The name of the query string parameter containing the URI.
+   *
+   * @param string
+   */
+  private $uriParamName;
+
   /**
    * Creates a new OptionsRequestSubscriber instance.
    *
@@ -40,10 +47,13 @@ class OptionsRequestSubscriber implements EventSubscriberInterface {
    *   The route provider.
    * @param \Symfony\Component\EventDispatcher\EventSubscriberInterface
    *   The decorated service.
+   * @param string $uri_param_name
+   *   The name of the query string parameter containing the URI.
    */
-  public function __construct(RouteProviderInterface $route_provider, EventSubscriberInterface $subject) {
+  public function __construct(RouteProviderInterface $route_provider, EventSubscriberInterface $subject, string $uri_param_name) {
     $this->routeProvider = $route_provider;
     $this->subject = $subject;
+    $this->uriParamName = $uri_param_name;
   }
 
   /**
@@ -79,7 +89,7 @@ class OptionsRequestSubscriber implements EventSubscriberInterface {
     }
     $response = $proxy->corsResponse($request);
     $cache_contexts = [
-      'url.query_args:' . Forwarder::QUERY_PARAM_URI,
+      'url.query_args:' . $this->uriParamName,
       'headers:Origin',
     ];
     $cacheability = (new CacheableMetadata())