Issue #2974221 by joachim, maks9889, heddn: add a process plugin for extracting an entity value

src/Plugin/migrate/process/EntityValue.php

+<?php
+
+namespace Drupal\migrate_plus\Plugin\migrate\process;
+
+use Drupal\Core\Entity\ContentEntityInterface;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\migrate\MigrateException;
+use Drupal\migrate\MigrateExecutableInterface;
+use Drupal\migrate\ProcessPluginBase;
+use Drupal\migrate\Row;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Extracts a specified field's value from an entity.
+ *
+ * This considers the source value to be an entity ID, and returns a field
+ * value from that field. The type of the entity and the field name must be
+ * specified. Optionally, the field property should be specified if it is not
+ * the default of 'value'.
+ *
+ * For content entities, if a langcode is given, that translation is loaded.
+ * The langcode is a reference so can be dynamic.
+ *
+ * Example:
+ * @code
+ * process:
+ *   field_foo:
+ *     plugin: entity_value
+ *     source: field_noderef/0/target_id
+ *     entity_type: node
+ *     langcode: @_langcode
+ *     field_name: field_foo
+ * @endcode
+ *
+ * @MigrateProcessPlugin(
+ *   id = "entity_value",
+ * )
+ */
+class EntityValue extends ProcessPluginBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * The entity type manager.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * The Field Name.
+   *
+   * @var string
+   */
+  protected $fieldName;
+
+  /**
+   * The langcode reference. False if not configured.
+   *
+   * @var string
+   */
+  protected $langCodeRef;
+
+  /**
+   * The storage for the configured entity type.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface|\Drupal\Core\Entity\RevisionableStorageInterface
+   */
+  protected $entityStorage;
+
+  /**
+   * Flag indicating whether there are multiple values.
+   *
+   * @var bool
+   */
+  protected $multiple;
+
+  /**
+   * Creates a EntityValue instance.
+   *
+   * @param array $configuration
+   *   A configuration array containing information about the plugin instance.
+   * @param string $plugin_id
+   *   The plugin_id for the plugin instance.
+   * @param mixed $plugin_definition
+   *   The plugin implementation definition.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
+   * @throws \InvalidArgumentException
+   */
+  public function __construct(
+    array $configuration,
+    $plugin_id,
+    $plugin_definition,
+    EntityTypeManagerInterface $entity_type_manager
+  ) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->entityTypeManager = $entity_type_manager;
+
+    if (empty($this->configuration['entity_type'])) {
+      throw new \InvalidArgumentException("'entity_type' configuration must be specified for the entity_value process plugin.");
+    }
+
+    $entity_type = $this->configuration['entity_type'];
+    $this->entityStorage = $this->entityTypeManager->getStorage($entity_type);
+
+    $this->langCodeRef = isset($this->configuration['langcode']) ? $this->configuration['langcode'] : NULL;
+
+    if (empty($this->configuration['field_name'])) {
+      throw new \InvalidArgumentException("'field_name' configuration must be specified for migrate_plus_entity_value process plugin.");
+    }
+
+    $this->fieldName = $this->configuration['field_name'];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('entity_type.manager')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function transform($value, MigrateExecutableInterface $migrateExecutable, Row $row, $destinationProperty) {
+    $this->multiple = is_array($value);
+    if (!isset($value)) {
+      return [];
+    }
+    $ids = $this->multiple ? $value : [$value];
+    $entities = $this->loadEntities($ids);
+
+    $langcode = $this->langCodeRef;
+    $arrays = array_map(function (EntityInterface $entity) use ($langcode) {
+      if ($entity instanceof ContentEntityInterface) {
+        if ($langcode) {
+          $entity = $entity->getTranslation($langcode);
+        }
+        else {
+          $entity = $entity->getUntranslated();
+        }
+      }
+      else {
+        if ($langcode) {
+          throw new \InvalidArgumentException('Langcode can only be used with content entities currently.');
+        }
+      }
+      try {
+        return $entity->get($this->fieldName)->getValue();
+      }
+      catch (\Exception $e) {
+        // Re-throw any exception thrown by the entity system.
+        throw new MigrateException("Got exception reading field value {$this->fieldName} entity with ID {$entity->id()} in migrate_plus_entity_value process plugin:" . $e->getMessage());
+      }
+    }, $entities);
+
+    $return = $this->multiple ? array_values($arrays) : ($arrays ? reset($arrays) : []);
+
+    return $return;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function multiple() {
+    return $this->multiple;
+  }
+
+  /**
+   * Load entities.
+   *
+   * @param array $ids
+   *   The entity IDs.
+   *
+   * @return \Drupal\Core\Entity\EntityInterface[]
+   *   The entities.
+   */
+  protected function loadEntities(array $ids) {
+    $entities = $this->entityStorage->loadMultiple($ids);
+    return $entities;
+  }
+
+}

tests/src/Kernel/Plugin/migrate/process/EntityValueTest.php

+<?php
+
+namespace Drupal\Tests\migrate_plus\Kernel\Plugin\migrate\process;
+
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\migrate\MigrateExecutableInterface;
+use Drupal\migrate\Row;
+use Drupal\node\Entity\Node;
+use Drupal\language\Entity\ConfigurableLanguage;
+
+/**
+ * Tests the entity_value plugin.
+ *
+ * @coversDefaultClass \Drupal\migrate_plus\Plugin\migrate\process\EntityValue
+ * @group migrate_drupal
+ */
+class EntityValueTest extends KernelTestBase {
+
+  /**
+   * The generated title.
+   *
+   * @var string
+   */
+  protected $title;
+
+  /**
+   * The generated Spanish title.
+   *
+   * @var string
+   */
+  protected $titleSpanish;
+
+  /**
+   * The generated node ID.
+   *
+   * @var int
+   */
+  protected $uid;
+
+  /**
+   * The plugin to test.
+   *
+   * @var \Drupal\migrate_plus\Plugin\migrate\process\EntityValue
+   */
+  protected $plugin;
+
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'migrate',
+    'migrate_plus',
+    'system',
+    'node',
+    'user',
+    'language',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    ConfigurableLanguage::createFromLangcode('es')->save();
+    $this->installSchema('system', ['sequences']);
+    $this->installSchema('node', 'node_access');
+    $this->installEntitySchema('user');
+    $this->installEntitySchema('node');
+
+    $this->title = $this->randomString();
+    $this->titleSpanish = $this->randomString();
+
+    $node = Node::create([
+      'type' => 'page',
+      'title' => $this->title,
+      'langcode' => 'en',
+    ]);
+    $node->save();
+
+    $node_es = $node->addTranslation('es');
+    $node_es->setTitle($this->titleSpanish);
+    $node_es->save();
+
+    $this->uid = $node->id();
+  }
+
+  /**
+   * Test the EntityLoad plugin succeeding.
+   *
+   * @covers ::transform
+   */
+  public function testEntityValueSuccess() {
+    $this->plugin = \Drupal::service('plugin.manager.migrate.process')
+      ->createInstance('entity_value', [
+        'entity_type' => 'node',
+        'field_name' => 'title',
+      ]);
+    $executable = $this->prophesize(MigrateExecutableInterface::class)
+      ->reveal();
+    $row = new Row();
+
+    // Ensure that the entity is returned if it really exists.
+    $value = $this->plugin->transform($this->uid, $executable, $row, 'dummmy');
+    $this->assertSame($this->title, $value[0]['value']);
+    $this->assertFalse($this->plugin->multiple());
+
+    // Ensure that an array of entities is returned.
+    $value = $this->plugin->transform([$this->uid], $executable, $row,
+      'dummmy');
+    $this->assertSame($this->title, $value[0][0]['value']);
+    $this->assertTrue($this->plugin->multiple());
+
+    // Ensure that the plugin returns [] if the entity doesn't exist.
+    $value = $this->plugin->transform(9999999, $executable, $row, 'dummmy');
+    $this->assertSame([], $value);
+    $this->assertFalse($this->plugin->multiple());
+
+    // Ensure that the plugin returns [] if NULL is passed.
+    $value = $this->plugin->transform(NULL, $executable, $row, 'dummmy');
+    $this->assertSame([], $value);
+    $this->assertFalse($this->plugin->multiple());
+  }
+
+  /**
+   * Test the EntityLoad plugin succeeding.
+   *
+   * @covers ::transform
+   */
+  public function testEntityValueLangSuccess() {
+    $this->plugin = \Drupal::service('plugin.manager.migrate.process')
+      ->createInstance('entity_value', [
+        'entity_type' => 'node',
+        'langcode' => 'es',
+        'field_name' => 'title',
+      ]);
+    $executable = $this->prophesize(MigrateExecutableInterface::class)
+      ->reveal();
+    $row = new Row();
+
+    // Ensure that the entity is returned if it really exists.
+    $value = $this->plugin->transform($this->uid, $executable, $row, 'dummmy');
+    $this->assertSame($this->titleSpanish, $value[0]['value']);
+    $this->assertFalse($this->plugin->multiple());
+
+    // Ensure that an array of entities is returned.
+    $value = $this->plugin->transform([$this->uid], $executable, $row,
+      'dummmy');
+    $this->assertSame($this->titleSpanish, $value[0][0]['value']);
+    $this->assertTrue($this->plugin->multiple());
+  }
+
+  /**
+   * Test the EntityLoad plugin throwing.
+   *
+   * @param mixed $config
+   *   the Plugin Config.
+   *
+   * @covers ::__construct
+   * @dataProvider entityValueFailureConfigData
+   */
+  public function testEntityValueConfig($config) {
+    $this->setExpectedException(\InvalidArgumentException::class);
+    $plugin = \Drupal::service('plugin.manager.migrate.process')
+      ->createInstance('entity_value', $config);
+  }
+
+  /**
+   * Provides data for entityLoadFailureConfigData.
+   *
+   * @return array
+   *   The data.
+   */
+  public function entityValueFailureConfigData() {
+    return [
+      [
+        [
+          'entity_type' => '',
+        ],
+      ],
+      [
+        [
+          'entity_type' => NULL,
+        ],
+      ],
+      [
+        [
+          'entity_type' => 'node',
+          'source' => '',
+        ],
+      ],
+      [
+        [
+          'entity_type' => 'node',
+          'source' => NULL,
+        ],
+      ],
+      [
+        [
+          'entity_type' => 'node',
+          'source' => 'test',
+          'field_name' => '',
+        ],
+      ],
+      [
+        [
+          'entity_type' => 'node',
+          'source' => 'test',
+          'field_name' => NULL,
+        ],
+      ],
+    ];
+  }
+
+}