Additional methods added to \Drupal\migrate_drupal\Plugin\migrate\field\FieldPluginBase to reduce code duplication in child classes.

Summary

• The base class for migrate filed plugins (\Drupal\migrate_drupal\Plugin\migrate\field\FieldPluginBase) now implements the remaining two interface methods: getFieldFormatterMap() and processFieldValues().
• If no custom code is needed in those methods, classes that are extending this base class can now leave the class body empty and only use the type_map annotation to map the field types.

Before

/**
 * @MigrateField(
 *   id = "number_default",
 *   type_map = {
 *     "number_integer" = "integer",
 *     "number_decimal" = "decimal",
 *     "number_float" = "float",
 *   },
 *   core = {7}
 * )
 */
class NumberField extends FieldPluginBase {

  /**
   * {@inheritdoc}
   */
  public function getFieldFormatterMap() {
    return [];
  }

  /**
   * {@inheritdoc}
   */
  public function processFieldValues(MigrationInterface $migration, $field_name, $data) {
    $process = [
      'plugin' => 'get',
      'source' => $field_name,
    ];
    $migration->mergeProcessOfProperty($field_name, $process);
  }

}

After

/**
 * @MigrateField(
 *   id = "number_default",
 *   type_map = {
 *     "number_integer" = "integer",
 *     "number_decimal" = "decimal",
 *     "number_float" = "float",
 *   },
 *   core = {7}
 * )
 */
class NumberField extends FieldPluginBase {}