Issue #2939322 by pookmish, silverham, swentel, dkosbob: Provide entity context to DS block fields

ds.services.yml

@@ -10,3 +10,8 @@ services:
     arguments: ['@entity_type.manager']
     tags:
       - { name: event_subscriber }
+  ds.ds_block_field_entity_context:
+    class: Drupal\ds\ContextProvider\DsBlockFieldEntityContext
+    arguments: ['@entity_type.manager']
+    tags:
+      - { name: 'context_provider' }

src/ContextProvider/DsBlockFieldEntityContext.php

+<?php
+
+namespace Drupal\ds\ContextProvider;
+
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Plugin\Context\Context;
+use Drupal\Core\Plugin\Context\ContextProviderInterface;
+use Drupal\Core\Plugin\Context\EntityContext;
+use Drupal\Core\Plugin\Context\EntityContextDefinition;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+
+/**
+ * Sets the current node as a context on node routes.
+ */
+class DsBlockFieldEntityContext implements ContextProviderInterface {
+
+  use StringTranslationTrait;
+
+  /**
+   * The Entity Type Manager.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * Constructs a new NodeRouteContext.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
+   *   The Entity Type Manager.
+   */
+  public function __construct(EntityTypeManagerInterface $entityTypeManager) {
+    $this->entityTypeManager = $entityTypeManager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRuntimeContexts(array $unqualified_context_ids) {
+    // We set these values at runtime in
+    // \Drupal\ds\Plugin\DsField\BlockBase::build(),
+    // so just create empty contexts.
+    $result = [];
+    $entity_type_ids = array_keys($this->entityTypeManager->getDefinitions());
+    foreach ($entity_type_ids as $entity_type_id) {
+      $empty_entity = NULL;
+      $context_definition = EntityContextDefinition::create($entity_type_id)->setRequired(FALSE);
+      $context = new Context($context_definition, $empty_entity);
+
+      $cacheability = new CacheableMetadata();
+      // Not cacheable.
+      $cacheability->setCacheMaxAge(0);
+      $context->addCacheableDependency($cacheability);
+
+      $result[$entity_type_id] = $context;
+    }
+    return $result;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getAvailableContexts() {
+    $contexts = [];
+    $entity_types = $this->entityTypeManager->getDefinitions();
+    foreach ($entity_types as $entity_type_id => $entity_type) {
+      $contexts[$entity_type_id] = EntityContext::fromEntityTypeId($entity_type_id, $this->t('@type set by DS Block Field', ['@type' => $entity_type->getLabel()]));
+    }
+    return $contexts;
+  }
+
+}

src/Form/BlockFieldForm.php

@@ -122,11 +122,11 @@ class BlockFieldForm extends FieldFormBase implements ContainerInjectionInterfac
     $block_id = $this->field['properties']['block'];
     $block = $manager->createInstance($block_id);
 
-    // Inject default theme in form state (Site branding needs it for instance).
+    // Create fake form state and inject default theme in form state (Site
+    // branding needs it for instance).
     $fake_form_state = new FormState();
     $default_theme = $this->config('system.theme')->get('default');
     $fake_form_state->set('block_theme', $default_theme);
-
     $block_config_form = $block->blockForm([], $fake_form_state);
     if ($block_config_form) {
       $url = Url::fromRoute('ds.manage_block_field_config', ['field_key' => $this->field['id']]);

src/Plugin/DsField/BlockBase.php

@@ -3,6 +3,8 @@
 namespace Drupal\ds\Plugin\DsField;
 
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Plugin\Context\Context;
+use Drupal\Core\Plugin\Context\ContextDefinition;
 use Drupal\Core\Plugin\Context\ContextHandlerInterface;
 use Drupal\Core\Plugin\Context\ContextRepositoryInterface;
 use Drupal\Core\Plugin\ContextAwarePluginInterface;
@@ -81,14 +83,26 @@ abstract class BlockBase extends DsFieldBase implements ContainerFactoryPluginIn
 
     $add_wrappers = isset($this->getFieldConfiguration()['properties']['add_block_wrappers']) && $this->getFieldConfiguration()['properties']['add_block_wrappers'];
 
-    if ($block->access(\Drupal::currentUser())) {
-      // Inject context values.
-      if ($block instanceof ContextAwarePluginInterface) {
-        $contexts = $this->contextRepository->getRuntimeContexts(array_values($block->getContextMapping()));
-        $this->contextHandler->applyContextMapping($block, $contexts);
+    // Inject context values.
+    if ($block instanceof ContextAwarePluginInterface) {
+      $contexts = $this->contextRepository->getRuntimeContexts(array_values($block->getContextMapping()));
+      // Set the configured entity now.
+      $entity_type_id = $this->configuration['entity']->getEntityTypeId();
+      if (isset($contexts["@ds.ds_block_field_entity_context:{$entity_type_id}"])) {
+        $contexts["@ds.ds_block_field_entity_context:{$entity_type_id}"]->getContextData()
+          ->setValue($this->configuration['entity']);
+        $contexts['view_mode'] = new Context(new ContextDefinition('string'), $this->configuration['view_mode']);
       }
+      $this->contextHandler->applyContextMapping($block, $contexts);
+    }
+
+    if ($block->access(\Drupal::currentUser())) {
       $block_build = $block->build();
 
+      if (Element::isEmpty($block_build)) {
+        return [];
+      }
+
       // If the user has chosen to add the block wrappers, theme as a block.
       if ($add_wrappers) {
         // @see \Drupal\block\BlockViewBuilder::buildPreRenderableBlock
@@ -108,7 +122,6 @@ abstract class BlockBase extends DsFieldBase implements ContainerFactoryPluginIn
         $render_element = $block_build;
       }
 
-
       // Merge cache contexts, tags and max-age.
       if ($contexts = $block->getCacheContexts()) {
         $render_element['#cache']['contexts'] = [];