Issue #2835626 by 20th, vijaycs85, himanshu-dixit, naveenvalecha, Jo Fitzgerald, Wim Leers, xjm, dawehner, catch, alexpott: Rename & document Drupal\Core\EventSubscriber\AcceptNegotiation406 KernelEvents::VIEW event subscriber

core/core.services.yml

@@ -1044,8 +1044,8 @@ services:
     arguments: ['@class_resolver', '@current_route_match', '%main_content_renderers%']
     tags:
       - { name: event_subscriber }
-  accept_negotiation_406:
-    class: Drupal\Core\EventSubscriber\AcceptNegotiation406
+  renderer_non_html:
+    class: Drupal\Core\EventSubscriber\RenderArrayNonHtmlSubscriber
     tags:
       - { name: event_subscriber }
   main_content_renderer.html:

core/lib/Drupal/Core/EventSubscriber/RenderArrayNonHtmlSubscriber.php

@@ -8,25 +8,23 @@ use Symfony\Component\HttpKernel\Exception\NotAcceptableHttpException;
 use Symfony\Component\HttpKernel\KernelEvents;
 
 /**
- * View subscriber rendering a 406 if we could not route or render a request.
- *
- * @todo fix or replace this in https://www.drupal.org/node/2364011
+ * Throws 406 if requesting non-HTML format and controller returns render array.
  */
-class AcceptNegotiation406 implements EventSubscriberInterface {
+class RenderArrayNonHtmlSubscriber implements EventSubscriberInterface {
 
   /**
-   * Throws an HTTP 406 error if we get this far, which we normally shouldn't.
+   * Throws an HTTP 406 error if client requested a non-HTML format.
    *
    * @param \Symfony\Component\HttpKernel\Event\GetResponseForControllerResultEvent $event
    *   The event to process.
    */
-  public function onViewDetect406(GetResponseForControllerResultEvent $event) {
+  public function onRespond(GetResponseForControllerResultEvent $event) {
     $request = $event->getRequest();
     $result = $event->getControllerResult();
 
     // If this is a render array then we assume that the router went with the
     // generic controller and not one with a format. If the format requested is
-    // not HTML though we can also assume that the requested format is invalid
+    // not HTML though, we can also assume that the requested format is invalid
     // so we provide a 406 response.
     if (is_array($result) && $request->getRequestFormat() !== 'html') {
       throw new NotAcceptableHttpException('Not acceptable format: ' . $request->getRequestFormat());
@@ -37,8 +35,7 @@ class AcceptNegotiation406 implements EventSubscriberInterface {
    * {@inheritdoc}
    */
   public static function getSubscribedEvents() {
-    $events[KernelEvents::VIEW][] = ['onViewDetect406', -10];
-
+    $events[KernelEvents::VIEW][] = ['onRespond', -10];
     return $events;
   }
 

core/modules/dynamic_page_cache/src/EventSubscriber/DynamicPageCacheSubscriber.php

@@ -82,7 +82,7 @@ class DynamicPageCacheSubscriber implements EventSubscriberInterface {
         // may be returning a domain object that a KernelEvents::VIEW subscriber
         // must turn into an actual response, but perhaps a format is being
         // requested that the subscriber does not support.
-        // @see \Drupal\Core\EventSubscriber\AcceptNegotiation406::onViewDetect406()
+        // @see \Drupal\Core\EventSubscriber\RenderArrayNonHtmlSubscriber::onResponse()
         'request_format',
       ],
       'bin' => 'dynamic_page_cache',

core/modules/system/tests/modules/render_array_non_html_subscriber_test/render_array_non_html_subscriber_test.info.yml

@@ -0,0 +1,6 @@
+name: 'Array rendering for non-HTML requests subscriber test'
+type: module
+description: 'Support module for RenderArrayNonHtmlSubscriberTest.'
+package: Testing
+version: VERSION
+core: 8.x

core/modules/system/tests/modules/render_array_non_html_subscriber_test/render_array_non_html_subscriber_test.routing.yml

@@ -0,0 +1,13 @@
+render_array_non_html_subscriber_test.raw_string:
+  path: '/render_array_non_html_subscriber_test/raw_string'
+  defaults:
+    _controller: '\Drupal\render_array_non_html_subscriber_test\RenderArrayNonHtmlSubscriberTestController::rawString'
+  requirements:
+    _access: 'TRUE'
+
+render_array_non_html_subscriber_test.render_array:
+  path: '/render_array_non_html_subscriber_test/render_array'
+  defaults:
+    _controller: '\Drupal\render_array_non_html_subscriber_test\RenderArrayNonHtmlSubscriberTestController::renderArray'
+  requirements:
+    _access: 'TRUE'

core/modules/system/tests/modules/render_array_non_html_subscriber_test/src/RenderArrayNonHtmlSubscriberTestController.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Drupal\render_array_non_html_subscriber_test;
+
+use Drupal\Core\Controller\ControllerBase;
+use Symfony\Component\HttpFoundation\Response;
+
+class RenderArrayNonHtmlSubscriberTestController extends ControllerBase {
+
+  /**
+   * @return string
+   */
+  public function rawString() {
+    return new Response($this->t('Raw controller response.'));
+  }
+
+  /**
+   * @return array
+   */
+  public function renderArray() {
+    return [
+      '#type' => 'html_tag',
+      '#tag' => 'p',
+      '#value' => $this->t('Controller response successfully rendered.'),
+    ];
+  }
+
+}

core/modules/system/tests/src/Functional/Render/RenderArrayNonHtmlSubscriberTest.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace Drupal\Tests\system\Functional\Render;
+
+use Drupal\Core\Url;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Functional test verifying that render array throws 406 for non-HTML requests.
+ *
+ * @group Render
+ */
+class RenderArrayNonHtmlSubscriberTest extends BrowserTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['render_array_non_html_subscriber_test'];
+
+  /**
+   * Tests handling of responses by events subscriber.
+   */
+  public function testResponses() {
+    // Test that event subscriber does not interfere with normal requests.
+    $url = Url::fromRoute('render_array_non_html_subscriber_test.render_array');
+
+    $this->drupalGet($url);
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertRaw(t('Controller response successfully rendered.'));
+
+    // Test that correct response code is returned for any non-HTML format.
+    foreach (['json', 'hal+json', 'xml', 'foo'] as $format) {
+      $url = Url::fromRoute('render_array_non_html_subscriber_test.render_array', [
+        '_format' => $format,
+      ]);
+
+      $this->drupalGet($url);
+      $this->assertSession()->statusCodeEquals(406);
+      $this->assertNoRaw(t('Controller response successfully rendered.'));
+    }
+
+    // Test that event subscriber does not interfere with raw string responses.
+    $url = Url::fromRoute('render_array_non_html_subscriber_test.raw_string', [
+      '_format' => 'foo',
+    ]);
+
+    $this->drupalGet($url);
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertRaw(t('Raw controller response.'));
+  }
+
+}