Issue #2785355 by timmillwood, dawehner, claudiu.cristea, borisson_: Expose...

Issue #2785355 by timmillwood, dawehner, claudiu.cristea, borisson_: Expose the class resolver on \Drupal

core/lib/Drupal.php

@@ -299,6 +299,23 @@ public static function cache($bin = 'default') {
     return static::getContainer()->get('cache.' . $bin);
   }
 
+  /**
+   * Retrieves the class resolver.
+   *
+   * This is to be used in procedural code such as module files to instantiate
+   * an object of a class that implements
+   * \Drupal\Core\DependencyInjection\ContainerInjectionInterface.
+   *
+   * One common usecase is to provide a class which contains the actual code
+   * of a hook implementation, without having to create a service.
+   *
+   * @return \Drupal\Core\DependencyInjection\ClassResolverInterface
+   *   The class resolver.
+   */
+  public static function classResolver() {
+    return static::getContainer()->get('class_resolver');
+  }
+
   /**
    * Returns an expirable key value store collection.
    *

core/tests/Drupal/Tests/Core/DrupalTest.php

@@ -102,7 +102,7 @@ public function testDatabase() {
   }
 
   /**
-   * Tests the service() method.
+   * Tests the cache() method.
    *
    * @covers ::cache
    */
@@ -111,6 +111,16 @@ public function testCache() {
     $this->assertNotNull(\Drupal::cache('test'));
   }
 
+  /**
+   * Tests the classResolver method.
+   *
+   * @covers ::classResolver
+   */
+  public function testClassResolver() {
+    $this->setMockContainerService('class_resolver');
+    $this->assertNotNull(\Drupal::classResolver());
+  }
+
   /**
    * Tests the keyValueExpirable() method.
    *