Make /user/register redirect optional

config/install/oe_authentication.settings.yml

@@ -3,3 +3,4 @@ register_path: 'eim/external/register.cgi'
 validation_path: 'TicketValidationService'
 assurance_level: TOP
 ticket_types: SERVICE,PROXY
+redirect_user_register_route: true

config/schema/oe_authentication.schema.yml

@@ -16,4 +16,7 @@ oe_authentication.settings:
       label: 'Application assurance levels'
     ticket_types:
       type: string
-      label: 'Application available ticket types'
+      label: 'Application available ticket types'
+    redirect_user_register_route:
+      type: boolean
+      label: 'Redirect Drupal user registration route to EU Login'

oe_authentication.services.yml

@@ -5,7 +5,8 @@ services:
       tags:
         - { name: access_check, applies_to: _external_user_access_check }
   oe_authentication.route_subscriber:
-    class: \Drupal\oe_authentication\Routing\RouteSubscriber
+    class: Drupal\oe_authentication\Routing\RouteSubscriber
+    arguments: ['@config.factory']
     tags:
       - { name: event_subscriber }
   oe_authentication.event_subscriber:

src/Controller/RegisterController.php

@@ -62,8 +62,9 @@ public function register(): TrustedRedirectResponse {
     $url = $this->getRegisterUrl()->toString();
     $response = new TrustedRedirectResponse($url);
 
-    $cache = new CacheableMetadata();
-    $cache->addCacheContexts(['user.roles:anonymous']);
+    $cache = (new CacheableMetadata())
+      ->addCacheContexts(['user.roles:anonymous'])
+      ->setCacheTags(['config:oe_authentication.settings']);
     $response->addCacheableDependency($cache);
 
     return $response;

src/Form/AuthenticationSettingsForm.php

@@ -4,8 +4,11 @@
 
 namespace Drupal\oe_authentication\Form;
 
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Form\ConfigFormBase;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Routing\RouteBuilderInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Settings form for module.
@@ -17,6 +20,36 @@ class AuthenticationSettingsForm extends ConfigFormBase {
    */
   const CONFIG_NAME = 'oe_authentication.settings';
 
+  /**
+   * The route builder service.
+   *
+   * @var \Drupal\Core\Routing\RouteBuilderInterface
+   */
+  protected $routeBuilder;
+
+  /**
+   * Constructs a new form instance.
+   *
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The factory for configuration objects.
+   * @param \Drupal\Core\Routing\RouteBuilderInterface $route_builder
+   *   The route builder service.
+   */
+  public function __construct(ConfigFactoryInterface $config_factory, RouteBuilderInterface $route_builder) {
+    parent::__construct($config_factory);
+    $this->routeBuilder = $route_builder;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('config.factory'),
+      $container->get('router.builder')
+    );
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -53,21 +86,35 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#title' => $this->t('Application available ticket types'),
       '#default_value' => $this->config(static::CONFIG_NAME)->get('ticket_types'),
     ];
+    $form['redirect_user_register_route'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Redirect user registration route to EU Login'),
+      '#default_value' => $this->config(static::CONFIG_NAME)->get('redirect_user_register_route'),
+    ];
     return parent::buildForm($form, $form_state);
   }
 
   /**
    * {@inheritdoc}
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
+    $original_redirect_user_register_route = $this->config(static::CONFIG_NAME)
+      ->get('redirect_user_register_route');
+
     $this->config(static::CONFIG_NAME)
       ->set('protocol', $form_state->getValue('protocol'))
       ->set('register_path', $form_state->getValue('register_path'))
       ->set('validation_path', $form_state->getValue('validation_path'))
       ->set('assurance_level', $form_state->getValue('assurance_level'))
       ->set('ticket_types', $form_state->getValue('ticket_types'))
+      ->set('redirect_user_register_route', $form_state->getValue('redirect_user_register_route'))
       ->save();
     parent::submitForm($form, $form_state);
+
+    // Rebuild the routes if the redirect user register config has changed.
+    if ($original_redirect_user_register_route != $form_state->getValue('redirect_user_register_route')) {
+      $this->routeBuilder->rebuild();
+    }
   }
 
   /**

src/Routing/RouteSubscriber.php

@@ -4,6 +4,7 @@
 
 namespace Drupal\oe_authentication\Routing;
 
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Routing\RouteSubscriberBase;
 use Symfony\Component\Routing\Route;
 use Symfony\Component\Routing\RouteCollection;
@@ -13,6 +14,23 @@
  */
 class RouteSubscriber extends RouteSubscriberBase {
 
+  /**
+   * The config factory service.
+   *
+   * @var \Drupal\Core\Config\ConfigFactoryInterface
+   */
+  protected $configFactory;
+
+  /**
+   * Constructs a new route event subscriber.
+   *
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The config factory service.
+   */
+  public function __construct(ConfigFactoryInterface $config_factory) {
+    $this->configFactory = $config_factory;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -33,12 +51,15 @@ protected function alterRoutes(RouteCollection $collection): void {
     }
 
     // Replace the core register route controller.
-    $route = $collection->get('user.register');
-    if ($route instanceof Route) {
-      $defaults = $route->getDefaults();
-      unset($defaults['_form']);
-      $defaults['_controller'] = '\Drupal\oe_authentication\Controller\RegisterController::register';
-      $route->setDefaults($defaults);
+    $config = $this->configFactory->get('oe_authentication.settings');
+    if ($config->get('redirect_user_register_route')) {
+      $route = $collection->get('user.register');
+      if ($route instanceof Route) {
+        $defaults = $route->getDefaults();
+        unset($defaults['_form']);
+        $defaults['_controller'] = '\Drupal\oe_authentication\Controller\RegisterController::register';
+        $route->setDefaults($defaults);
+      }
     }
 
     // Replace the cas callback route controller.

tests/features/ecas-register.feature

@@ -1,12 +1,22 @@
-@javascript @ecas-login
+@api @javascript @ecas-login
 Feature: Register through OE Authentication
   In order to be able to have new users
   As an anonymous user of the system
   I need to be able to go to the registration URL
 
+  @DrupalLogin @BackupAuthConfigs @RebuildRouter
   Scenario: Register
     Given I am an anonymous user
     When I visit "the user registration page"
     # Redirected to the Ecas mockup server.
     And I click "External"
     Then I should see "Create an account"
+
+    Given I am logged in as a user with the "administer authentication configuration" permission
+    When I am on "the Authentication configuration page"
+    And I uncheck "Redirect user registration route to EU Login"
+    Then I press "Save configuration"
+
+    Given I am an anonymous user
+    When I visit "the user registration page"
+    Then I should see "Create new account"