diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 37d5ec2..7dc62f3 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -2281,9 +2281,8 @@ function template_preprocess_page(&$variables) {
     );
   }
 
-  $request = \Drupal::request();
-  if ($request->attributes->has('node')) {
-    $variables['node'] = $request->attributes->get('node');
+  if ($node = \Drupal::request()->attributes->get('node')) {
+    $variables['node'] = $variables['node'];
   }
 
   // Prepare render array for messages. drupal_get_messages() is called later,
diff --git a/core/modules/book/lib/Drupal/book/Plugin/Block/BookNavigationBlock.php b/core/modules/book/lib/Drupal/book/Plugin/Block/BookNavigationBlock.php
index d8aa371..571a91e 100644
--- a/core/modules/book/lib/Drupal/book/Plugin/Block/BookNavigationBlock.php
+++ b/core/modules/book/lib/Drupal/book/Plugin/Block/BookNavigationBlock.php
@@ -8,6 +8,9 @@
 namespace Drupal\book\Plugin\Block;
 
 use Drupal\block\BlockBase;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\HttpFoundation\Request;
 
 /**
  * Provides a 'Book navigation' block.
@@ -18,7 +21,44 @@
  *   category = @Translation("Menus")
  * )
  */
-class BookNavigationBlock extends BlockBase {
+class BookNavigationBlock extends BlockBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * The request object.
+   *
+   * @var \Symfony\Component\HttpFoundation\Request
+   */
+  protected $request;
+
+  /**
+   * Constructs a Drupal\Component\Plugin\PluginBase object.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param array $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The request object.
+   */
+  public function __construct(array $configuration, $plugin_id, array $plugin_definition, Request $request) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->request = $request;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, array $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('request')
+    );
+  }
 
   /**
    * {@inheritdoc}
@@ -61,9 +101,7 @@ public function blockSubmit($form, &$form_state) {
    */
   public function build() {
     $current_bid = 0;
-    $request = \Drupal::request();
-    if ($request->attributes->has('node')) {
-      $node = $request->attributes->get('node');
+    if ($node = $this->request->get('node')) {
       $current_bid = empty($node->book['bid']) ? 0 : $node->book['bid'];
     }
     if ($this->configuration['block_mode'] == 'all pages') {
diff --git a/core/modules/node/lib/Drupal/node/Plugin/views/argument_default/Node.php b/core/modules/node/lib/Drupal/node/Plugin/views/argument_default/Node.php
index b920d11..59d66ce 100644
--- a/core/modules/node/lib/Drupal/node/Plugin/views/argument_default/Node.php
+++ b/core/modules/node/lib/Drupal/node/Plugin/views/argument_default/Node.php
@@ -45,6 +45,7 @@ class Node extends ArgumentDefaultPluginBase {
    */
   public function __construct(array $configuration, $plugin_id, array $plugin_definition, Request $request) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
+
     $this->request = $request;
   }
 
@@ -64,11 +65,8 @@ public static function create(ContainerInterface $container, array $configuratio
    * {@inheritdoc}
    */
   public function getArgument() {
-    if ($this->request->attributes->has('node')) {
-      $node = $this->request->attributes->get('node');
-      if ($node instanceof NodeInterface) {
-        return $node->id();
-      }
+    if (($node = $this->request->attributes->get('node')) && $node instanceof NodeInterface) {
+      return $node->id();
     }
   }
 }
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index c7e2785..24fc6ed 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -595,12 +595,8 @@ function node_is_page(EntityInterface $node) {
  */
 function node_preprocess_html(&$variables) {
   // If on an individual node page, add the node type to body classes.
-  $request = \Drupal::request();
-  if ($request->attributes->has('node')) {
-    $node = $request->attributes->get('node');
-    if ($node instanceof NodeInterface) {
-      $variables['attributes']['class'][] = drupal_html_class('node-type-' . $node->getType());
-    }
+  if (($node = \Drupal::request()->attributes->get('node')) && $node instanceof NodeInterface) {
+    $variables['attributes']['class'][] = drupal_html_class('node-type-' . $node->getType());
   }
 }
 
@@ -1172,9 +1168,8 @@ function node_block_access($block) {
     // For blocks with node types associated, if the node type does not match
     // the settings from this block, deny access to it.
     $request = \Drupal::request();
-    if ($request->attributes->has('node')) {
+    if ($node = \Drupal::request()->attributes->get('node')) {
       // Page has node.
-      $node = $request->attributes->get('node');
       return in_array($node->bundle(), $allowed_types);
     }
     // This is a node creation page.
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/views/argument_default/Tid.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/views/argument_default/Tid.php
index 620767e..f94efd1 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/views/argument_default/Tid.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Plugin/views/argument_default/Tid.php
@@ -165,12 +165,8 @@ public function getArgument() {
     }
     // Load default argument from node.
     if (!empty($this->options['node'])) {
-      if ($this->request->attributes->has('node')) {
-        $node = $this->request->attributes->get('node');
-      }
-
       // Just check, if a node could be detected.
-      if (!empty($node) && $node instanceof NodeInterface) {
+      if (($node = $this->request->attributes->has('node')) && $node instanceof NodeInterface) {
         $taxonomy = array();
         $instances = field_info_instances('node', $node->getType());
         foreach ($instances as $instance) {
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument/Date.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument/Date.php
index b9cf60c..3ac31eb 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument/Date.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument/Date.php
@@ -101,11 +101,9 @@ public function getDefaultArgument($raw = FALSE) {
       return date($this->argFormat, REQUEST_TIME);
     }
     elseif (!$raw && in_array($this->options['default_argument_type'], array('node_created', 'node_changed'))) {
-      if ($this->request->attributes->has('node')) {
-        $node = $this->request->attributes->get('node');
-      }
+      $node = $this->request->attributes->get('node');
 
-      if (empty($node) || !$node instanceof NodeInterface) {
+      if (!($node instanceof NodeInterface)) {
         return parent::getDefaultArgument();
       }
       elseif ($this->options['default_argument_type'] == 'node_created') {