Issue #2256355 by tim.plunkett: Make block plugins usable outside the block entity context.

core/modules/block/block.services.yml

 services:
   plugin.manager.block:
-    class: Drupal\block\Plugin\Type\BlockManager
+    class: Drupal\block\BlockManager
     arguments: ['@container.namespaces', '@cache.discovery', '@language_manager', '@module_handler', '@string_translation']
   theme.negotiator.block.admin_demo:
     class: Drupal\block\Theme\AdminDemoNegotiator

core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/Block/CustomBlockBlock.php

@@ -8,12 +8,12 @@
 namespace Drupal\custom_block\Plugin\Block;
 
 use Drupal\block\BlockBase;
+use Drupal\block\BlockManagerInterface;
 use Drupal\Core\Entity\EntityManager;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Session\AccountInterface;
-use Drupal\block\Plugin\Type\BlockManager;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
@@ -31,7 +31,7 @@ class CustomBlockBlock extends BlockBase implements ContainerFactoryPluginInterf
   /**
    * The Plugin Block Manager.
    *
-   * @var \Drupal\block\Plugin\Type\BlockManager.
+   * @var \Drupal\block\BlockManagerInterface.
    */
   protected $blockManager;
 
@@ -65,7 +65,7 @@ class CustomBlockBlock extends BlockBase implements ContainerFactoryPluginInterf
    *   The plugin ID for the plugin instance.
    * @param mixed $plugin_definition
    *   The plugin implementation definition.
-   * @param \Drupal\block\Plugin\Type\BlockManager
+   * @param \Drupal\block\BlockManagerInterface
    *   The Plugin Block Manager.
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager service.
@@ -74,7 +74,7 @@ class CustomBlockBlock extends BlockBase implements ContainerFactoryPluginInterf
    * @param \Drupal\Core\Session\AccountInterface $account
    *   The account for which view access should be checked.
    */
-  public function __construct(array $configuration, $plugin_id, $plugin_definition, BlockManager $block_manager, EntityManagerInterface $entity_manager, ModuleHandlerInterface $module_handler, AccountInterface $account) {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, BlockManagerInterface $block_manager, EntityManagerInterface $entity_manager, ModuleHandlerInterface $module_handler, AccountInterface $account) {
     parent::__construct($configuration, $plugin_id, $plugin_definition);
 
     $this->blockManager = $block_manager;

core/modules/block/lib/Drupal/block/BlockBase.php

@@ -25,6 +25,18 @@
  */
 abstract class BlockBase extends PluginBase implements BlockPluginInterface {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function label() {
+    if (!empty($this->configuration['label'])) {
+      return $this->configuration['label'];
+    }
+
+    $definition = $this->getPluginDefinition();
+    return $definition['admin_label'];
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -60,6 +72,7 @@ public function setConfiguration(array $configuration) {
    */
   protected function baseConfigurationDefaults() {
     return array(
+      'id' => $this->getPluginId(),
       'label' => '',
       'provider' => $this->pluginDefinition['provider'],
       'label_display' => BlockInterface::BLOCK_LABEL_VISIBLE,
@@ -126,7 +139,7 @@ public function buildConfigurationForm(array $form, array &$form_state) {
       '#type' => 'textfield',
       '#title' => $this->t('Title'),
       '#maxlength' => 255,
-      '#default_value' => !empty($this->configuration['label']) ? $this->configuration['label'] : $definition['admin_label'],
+      '#default_value' => $this->label(),
       '#required' => TRUE,
     );
     $form['label_display'] = array(

core/modules/block/lib/Drupal/block/BlockListBuilder.php

@@ -7,7 +7,7 @@
 
 namespace Drupal\block;
 
-use Drupal\Component\Plugin\PluginManagerInterface;
+use Drupal\block\BlockManagerInterface;
 use Drupal\Component\Serialization\Json;
 use Drupal\Component\Utility\String;
 use Drupal\Core\Cache\Cache;
@@ -50,7 +50,7 @@ class BlockListBuilder extends ConfigEntityListBuilder implements FormInterface
   /**
    * The block manager.
    *
-   * @var \Drupal\Component\Plugin\PluginManagerInterface
+   * @var \Drupal\block\BlockManagerInterface
    */
   protected $blockManager;
 
@@ -61,10 +61,10 @@ class BlockListBuilder extends ConfigEntityListBuilder implements FormInterface
    *   The entity type definition.
    * @param \Drupal\Core\Entity\EntityStorageInterface $storage
    *   The entity storage class.
-   * @param \Drupal\Component\Plugin\PluginManagerInterface $block_manager
+   * @param \Drupal\block\BlockManagerInterface $block_manager
    *   The block manager.
    */
-  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, PluginManagerInterface $block_manager) {
+  public function __construct(EntityTypeInterface $entity_type, EntityStorageInterface $storage, BlockManagerInterface $block_manager) {
     parent::__construct($entity_type, $storage);
 
     $this->blockManager = $block_manager;
@@ -334,13 +334,7 @@ public function buildForm(array $form, array &$form_state) {
     $form['place_blocks']['list']['#attributes']['class'][] = 'entity-meta';
 
     // Sort the plugins first by category, then by label.
-    $plugins = $this->blockManager->getDefinitions();
-    uasort($plugins, function ($a, $b) {
-      if ($a['category'] != $b['category']) {
-        return strnatcasecmp($a['category'], $b['category']);
-      }
-      return strnatcasecmp($a['admin_label'], $b['admin_label']);
-    });
+    $plugins = $this->blockManager->getSortedDefinitions();
     foreach ($plugins as $plugin_id => $plugin_definition) {
       $category = String::checkPlain($plugin_definition['category']);
       $category_key = 'category-' . $category;

core/modules/block/lib/Drupal/block/Plugin/Type/BlockManager.php → core/modules/block/lib/Drupal/block/BlockManager.php

@@ -2,10 +2,10 @@
 
 /**
  * @file
- * Contains \Drupal\block\Plugin\Type\BlockManager.
+ * Contains \Drupal\block\BlockManager.
  */
 
-namespace Drupal\block\Plugin\Type;
+namespace Drupal\block;
 
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
@@ -21,7 +21,8 @@
  *
  * @see \Drupal\block\BlockPluginInterface
  */
-class BlockManager extends DefaultPluginManager {
+class BlockManager extends DefaultPluginManager implements BlockManagerInterface {
+
   use StringTranslationTrait;
 
   /**
@@ -32,7 +33,7 @@ class BlockManager extends DefaultPluginManager {
   protected $moduleData;
 
   /**
-   * Constructs a new \Drupal\block\Plugin\Type\BlockManager object.
+   * Constructs a new \Drupal\block\BlockManager object.
    *
    * @param \Traversable $namespaces
    *   An object that implements \Traversable which contains the root paths
@@ -90,10 +91,7 @@ protected function getModuleName($module) {
   }
 
   /**
-   * Gets the names of all block categories.
-   *
-   * @return array
-   *   An array of translated categories, sorted alphabetically.
+   * {@inheritdoc}
    */
   public function getCategories() {
     $categories = array_unique(array_values(array_map(function ($definition) {
@@ -103,4 +101,19 @@ public function getCategories() {
     return $categories;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getSortedDefinitions() {
+    // Sort the plugins first by category, then by label.
+    $definitions = $this->getDefinitions();
+    uasort($definitions, function ($a, $b) {
+      if ($a['category'] != $b['category']) {
+        return strnatcasecmp($a['category'], $b['category']);
+      }
+      return strnatcasecmp($a['admin_label'], $b['admin_label']);
+    });
+    return $definitions;
+  }
+
 }

core/modules/block/lib/Drupal/block/BlockManagerInterface.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\block\BlockManagerInterface.
+ */
+
+namespace Drupal\block;
+
+/**
+ * Provides an interface for the discovery and instantiation of block plugins.
+ */
+interface BlockManagerInterface {
+
+  /**
+   * Gets the names of all block categories.
+   *
+   * @return array
+   *   An array of translated categories, sorted alphabetically.
+   */
+  public function getCategories();
+
+  /**
+   * Gets the sorted definitions.
+   *
+   * @return array
+   *   An array of plugin definitions, sorted by category and admin label.
+   */
+  public function getSortedDefinitions();
+
+}

core/modules/block/lib/Drupal/block/BlockPluginInterface.php

@@ -23,6 +23,17 @@
  */
 interface BlockPluginInterface extends ConfigurablePluginInterface, PluginFormInterface, PluginInspectionInterface, CacheableInterface {
 
+  /**
+   * Returns the user-facing block label.
+   *
+   * @todo Provide other specific label-related methods in
+   *   https://drupal.org/node/2025649.
+   *
+   * @return string
+   *   The block label.
+   */
+  public function label();
+
   /**
    * Indicates whether the block should be shown.
    *

core/modules/block/lib/Drupal/block/Controller/CategoryAutocompleteController.php

@@ -7,7 +7,7 @@
 
 namespace Drupal\block\Controller;
 
-use Drupal\block\Plugin\Type\BlockManager;
+use Drupal\block\BlockManagerInterface;
 use Drupal\Component\Utility\String;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -22,17 +22,17 @@ class CategoryAutocompleteController implements ContainerInjectionInterface {
   /**
    * The block manager.
    *
-   * @var \Drupal\block\Plugin\Type\BlockManager
+   * @var \Drupal\block\BlockManagerInterface
    */
   protected $blockManager;
 
   /**
    * Constructs a new CategoryAutocompleteController.
    *
-   * @param \Drupal\block\Plugin\Type\BlockManager $block_manager
+   * @param \Drupal\block\BlockManagerInterface $block_manager
    *   The block manager.
    */
-  public function __construct(BlockManager $block_manager) {
+  public function __construct(BlockManagerInterface $block_manager) {
     $this->blockManager = $block_manager;
   }
 

core/modules/block/lib/Drupal/block/Tests/BlockInterfaceTest.php

@@ -44,6 +44,7 @@ public function testBlockInterface() {
       'label' => 'Custom Display Message',
     );
     $expected_configuration = array(
+      'id' => 'test_block_instantiation',
       'label' => 'Custom Display Message',
       'provider' => 'block_test',
       'label_display' => BlockInterface::BLOCK_LABEL_VISIBLE,

core/modules/block/lib/Drupal/block/Tests/BlockStorageUnitTest.php

@@ -99,6 +99,7 @@ protected function createTests() {
       'region' => '-1',
       'plugin' => 'test_html',
       'settings' => array(
+        'id' => 'test_html',
         'label' => '',
         'provider' => 'block_test',
         'label_display' => BlockInterface::BLOCK_LABEL_VISIBLE,

core/modules/block/tests/Drupal/block/Tests/CategoryAutocompleteTest.php

@@ -37,9 +37,7 @@ public static function getInfo() {
   }
 
   public function setUp() {
-    $block_manager = $this->getMockBuilder('Drupal\block\Plugin\Type\BlockManager')
-      ->disableOriginalConstructor()
-      ->getMock();
+    $block_manager = $this->getMock('Drupal\block\BlockManagerInterface');
     $block_manager->expects($this->any())
       ->method('getCategories')
       ->will($this->returnValue(array('Comment', 'Node', 'None & Such', 'User')));

core/modules/language/lib/Drupal/language/Form/NegotiationConfigureForm.php

@@ -7,7 +7,7 @@
 
 namespace Drupal\language\Form;
 
-use Drupal\block\Plugin\Type\BlockManager;
+use Drupal\block\BlockManagerInterface;
 use Drupal\Component\Utility\String;
 use Drupal\Component\Utility\Unicode;
 use Drupal\Component\Utility\Xss;
@@ -48,7 +48,7 @@ class NegotiationConfigureForm extends FormBase {
   /**
    * The block manager.
    *
-   * @var \Drupal\block\Plugin\Type\BlockManager
+   * @var \Drupal\block\BlockManagerInterface
    */
   protected $blockManager;
 
@@ -61,10 +61,10 @@ class NegotiationConfigureForm extends FormBase {
    *   The language manager.
    * @param \Drupal\language\LanguageNegotiatorInterface $negotiator
    *   The language negotiation methods manager.
-   * @param \Drupal\block\Plugin\Type\BlockManager $block_manager
+   * @param \Drupal\block\BlockManagerInterface $block_manager
    *   The block manager, or NULL if not available.
    */
-  public function __construct(ConfigFactoryInterface $config_factory, ConfigurableLanguageManagerInterface $language_manager, LanguageNegotiatorInterface $negotiator, BlockManager $block_manager = NULL) {
+  public function __construct(ConfigFactoryInterface $config_factory, ConfigurableLanguageManagerInterface $language_manager, LanguageNegotiatorInterface $negotiator, BlockManagerInterface $block_manager = NULL) {
     $this->languageTypes = $config_factory->get('language.types');
     $this->languageManager = $language_manager;
     $this->negotiator = $negotiator;