SHS-5811: Add "logout" button to sites

composer.json

@@ -1,5 +1,5 @@
 {
-    "name": "su-sws/stanford_samlauth",
+    "name": "fourkitchens/stanford_samlauth",
     "type": "drupal-custom-module",
     "license": "GPL-2.0-or-later",
     "minimum-stability": "dev",

src/Plugin/Block/SamlLoginBlock.php

@@ -17,7 +17,7 @@
  *
  * @Block(
  *  id = "stanford_samlauth_login_block",
- *  admin_label = @Translation("SAML SUNetID Block")
+ *  admin_label = @Translation("SAML SUNetID Login Block")
  * )
  */
 class SamlLoginBlock extends BlockBase implements ContainerFactoryPluginInterface {

src/Plugin/Block/SamlLogoutBlock.php

@@ -0,0 +1,129 @@
+<?php
+
+namespace Drupal\stanford_samlauth\Plugin\Block;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\Core\Url;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\RequestStack;
+
+/**
+ * Provides a 'Saml Logout Block' block.
+ *
+ * @Block(
+ *  id = "stanford_samlauth_logout_block",
+ *  admin_label = @Translation("SAML SUNetID Logout Block")
+ * )
+ */
+class SamlLogoutBlock extends BlockBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * Current uri the block is displayed on.
+   *
+   * @var string
+   */
+  protected $currentUri;
+
+  /**
+   * {@inheritDoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('request_stack')
+    );
+  }
+
+  /**
+   * Block constructor.
+   *
+   * @param array $configuration
+   *   Configuration settings.
+   * @param string $plugin_id
+   *   Block machine name.
+   * @param array $plugin_definition
+   *   Plugin definition.
+   * @param \Symfony\Component\HttpFoundation\RequestStack $requestStack
+   *   Current request stack object.
+   */
+  public function __construct(array $configuration, string $plugin_id, array $plugin_definition, RequestStack $requestStack) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+    $this->currentUri = $requestStack->getCurrentRequest()?->getPathInfo();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultConfiguration() {
+    return ['link_text' => 'SUNetID Logout'] + parent::defaultConfiguration();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function blockForm($form, FormStateInterface $form_state) {
+    $form['link_text'] = [
+      '#type' => 'textfield',
+      '#title' => $this->t('SUNetID log-out link text'),
+      '#description' => $this->t('Add text to show a link for authenticated users.'),
+      '#default_value' => $this->configuration['link_text'],
+      '#required' => TRUE,
+    ];
+    return $form;
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  public function getCacheContexts() {
+    $context = parent::getCacheContexts();
+    // Make the block cache different for each page since the login link has a
+    // destination parameter.
+    return Cache::mergeContexts($context, ['url.path']);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function access(AccountInterface $account, $return_as_object = FALSE) {
+    $access = AccessResult::allowedIf($account->isAuthenticated());
+    return $return_as_object ? $access : $access->isAllowed();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function blockSubmit($form, FormStateInterface $form_state) {
+    $this->configuration['link_text'] = $form_state->getValue('link_text');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function build() {
+    $url = Url::fromRoute('user.logout', ['destination' => $this->currentUri]);
+    $build = [];
+    $build['logout'] = [
+      '#type' => 'html_tag',
+      '#tag' => 'a',
+      '#value' => $this->configuration['link_text'],
+      '#attributes' => [
+        'rel' => 'nofollow',
+        'href' => $url->toString(),
+        'class' => [
+          'su-button',
+          'decanter-button',
+        ],
+      ],
+    ];
+    return $build;
+  }
+
+}