Issue #1740378 by xjm, Désiré, alexpott | heyrocker: Implement renames in the import cycle.

core/lib/Drupal/Core/Config/ConfigImporter.php

@@ -11,6 +11,7 @@
 use Drupal\Core\Extension\ThemeHandlerInterface;
 use Drupal\Component\Utility\String;
 use Drupal\Core\Config\Entity\ImportableEntityStorageInterface;
+use Drupal\Core\Config\ConfigEvents;
 use Drupal\Core\DependencyInjection\DependencySerialization;
 use Drupal\Core\Entity\EntityStorageException;
 use Drupal\Core\Lock\LockBackendInterface;
@@ -263,12 +264,12 @@ protected function getEmptyExtensionsProcessedList() {
    *
    * @param array $ops
    *   The operations to check for changes. Defaults to all operations, i.e.
-   *   array('delete', 'create', 'update').
+   *   array('delete', 'create', 'update', 'rename').
    *
    * @return bool
    *   TRUE if there are changes to process and FALSE if not.
    */
-  public function hasUnprocessedConfigurationChanges($ops = array('delete', 'create', 'update')) {
+  public function hasUnprocessedConfigurationChanges($ops = array('delete', 'create', 'rename', 'update')) {
     foreach ($ops as $op) {
       if (count($this->getUnprocessedConfiguration($op))) {
         return TRUE;
@@ -291,7 +292,7 @@ public function getProcessedConfiguration() {
    * Sets a change as processed.
    *
    * @param string $op
-   *   The change operation performed, either delete, create or update.
+   *   The change operation performed, either delete, create, rename, or update.
    * @param string $name
    *   The name of the configuration processed.
    */
@@ -304,7 +305,7 @@ protected function setProcessedConfiguration($op, $name) {
    *
    * @param string $op
    *   The change operation to get the unprocessed list for, either delete,
-   *   create or update.
+   *   create, rename, or update.
    *
    * @return array
    *   An array of configuration names.
@@ -586,7 +587,7 @@ public function processConfigurations(array &$context) {
     // into account.
     if ($this->totalConfigurationToProcess == 0) {
       $this->storageComparer->reset();
-      foreach (array('delete', 'create', 'update') as $op) {
+      foreach (array('delete', 'create', 'rename', 'update') as $op) {
         foreach ($this->getUnprocessedConfiguration($op) as $name) {
           $this->totalConfigurationToProcess += count($this->getUnprocessedConfiguration($op));
         }
@@ -662,7 +663,7 @@ protected function getNextExtensionOperation() {
   protected function getNextConfigurationOperation() {
     // The order configuration operations is processed is important. Deletes
     // have to come first so that recreates can work.
-    foreach (array('delete', 'create', 'update') as $op) {
+    foreach (array('delete', 'create', 'rename', 'update') as $op) {
       $config_names = $this->getUnprocessedConfiguration($op);
       if (!empty($config_names)) {
         return array(
@@ -685,6 +686,19 @@ protected function getNextConfigurationOperation() {
    */
   public function validate() {
     if (!$this->validated) {
+      // Validate renames.
+      foreach ($this->getUnprocessedConfiguration('rename') as $name) {
+        $names = $this->storageComparer->extractRenameNames($name);
+        $old_entity_type_id = $this->configManager->getEntityTypeIdByName($names['old_name']);
+        $new_entity_type_id = $this->configManager->getEntityTypeIdByName($names['new_name']);
+        if ($old_entity_type_id != $new_entity_type_id) {
+          $this->logError($this->t('Entity type mismatch on rename. !old_type not equal to !new_type for existing configuration !old_name and staged configuration !new_name.', array('old_type' => $old_entity_type_id, 'new_type' => $new_entity_type_id, 'old_name' => $names['old_name'], 'new_name' => $names['new_name'])));
+        }
+        // Has to be a configuration entity.
+        if (!$old_entity_type_id) {
+          $this->logError($this->t('Rename operation for simple configuration. Existing configuration !old_name and staged configuration !new_name.', array('old_name' => $names['old_name'], 'new_name' => $names['new_name'])));
+        }
+      }
       $this->eventDispatcher->dispatch(ConfigEvents::IMPORT_VALIDATE, new ConfigImporterEvent($this));
       if (count($this->getErrors())) {
         throw new ConfigImporterException('There were errors validating the config synchronization.');
@@ -787,6 +801,20 @@ protected function processExtension($type, $op, $name) {
    *   TRUE is to continue processing, FALSE otherwise.
    */
   protected function checkOp($op, $name) {
+    if ($op == 'rename') {
+      $names = $this->storageComparer->extractRenameNames($name);
+      $target_exists = $this->storageComparer->getTargetStorage()->exists($names['new_name']);
+      if ($target_exists) {
+        // If the target exists, the rename has already occurred as the
+        // result of a secondary configuration write. Change the operation
+        // into an update. This is the desired behavior since renames often
+        // have to occur together. For example, renaming a node type must
+        // also result in renaming its field instances and entity displays.
+        $this->storageComparer->moveRenameToUpdate($name);
+        return FALSE;
+      }
+      return TRUE;
+    }
     $target_exists = $this->storageComparer->getTargetStorage()->exists($name);
     switch ($op) {
       case 'delete':
@@ -862,7 +890,7 @@ protected function importConfig($op, $name) {
    *
    * @param string $op
    *   The change operation to get the unprocessed list for, either delete,
-   *   create or update.
+   *   create, rename, or update.
    * @param string $name
    *   The name of the configuration to process.
    *
@@ -875,6 +903,10 @@ protected function importConfig($op, $name) {
    *   otherwise.
    */
   protected function importInvokeOwner($op, $name) {
+    // Renames are handled separately.
+    if ($op == 'rename') {
+      return $this->importInvokeRename($name);
+    }
     // Validate the configuration object name before importing it.
     // Config::validateName($name);
     if ($entity_type = $this->configManager->getEntityTypeIdByName($name)) {
@@ -900,6 +932,45 @@ protected function importInvokeOwner($op, $name) {
       $this->setProcessedConfiguration($op, $name);
       return TRUE;
     }
+    return FALSE;
+  }
+
+  /**
+   * Imports a configuration entity rename.
+   *
+   * @param string $rename_name
+   *   The rename configuration name, as provided by
+   *   \Drupal\Core\Config\StorageComparer::createRenameName().
+   *
+   * @return bool
+   *   TRUE if the configuration was imported as a configuration entity. FALSE
+   *   otherwise.
+   *
+   * @see \Drupal\Core\Config\ConfigImporter::createRenameName()
+   */
+  protected function importInvokeRename($rename_name) {
+    $names = $this->storageComparer->extractRenameNames($rename_name);
+    $entity_type_id = $this->configManager->getEntityTypeIdByName($names['old_name']);
+    $old_config = new Config($names['old_name'], $this->storageComparer->getTargetStorage(), $this->eventDispatcher, $this->typedConfigManager);
+    if ($old_data = $this->storageComparer->getTargetStorage()->read($names['old_name'])) {
+      $old_config->initWithData($old_data);
+    }
+
+    $data = $this->storageComparer->getSourceStorage()->read($names['new_name']);
+    $new_config = new Config($names['new_name'], $this->storageComparer->getTargetStorage(), $this->eventDispatcher, $this->typedConfigManager);
+    if ($data !== FALSE) {
+      $new_config->setData($data);
+    }
+
+    $entity_storage = $this->configManager->getEntityManager()->getStorage($entity_type_id);
+    // Call to the configuration entity's storage to handle the configuration
+    // change.
+    if (!($entity_storage instanceof ImportableEntityStorageInterface)) {
+      throw new EntityStorageException(String::format('The entity storage "@storage" for the "@entity_type" entity type does not support imports', array('@storage' => get_class($entity_storage), '@entity_type' => $entity_type_id)));
+    }
+    $entity_storage->importRename($names['old_name'], $new_config, $old_config);
+    $this->setProcessedConfiguration('rename', $rename_name);
+    return TRUE;
   }
 
   /**

core/lib/Drupal/Core/Config/ConfigManager.php

@@ -100,7 +100,10 @@ public function getConfigFactory() {
   /**
    * {@inheritdoc}
    */
-  public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $name) {
+  public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $source_name, $target_name = NULL) {
+    if (!isset($target_name)) {
+      $target_name = $source_name;
+    }
     // @todo Replace with code that can be autoloaded.
     //   https://drupal.org/node/1848266
     require_once __DIR__ . '/../../Component/Diff/DiffEngine.php';
@@ -111,8 +114,8 @@ public function diff(StorageInterface $source_storage, StorageInterface $target_
     $dumper = new Dumper();
     $dumper->setIndentation(2);
 
-    $source_data = explode("\n", $dumper->dump($source_storage->read($name), PHP_INT_MAX));
-    $target_data = explode("\n", $dumper->dump($target_storage->read($name), PHP_INT_MAX));
+    $source_data = explode("\n", $dumper->dump($source_storage->read($source_name), PHP_INT_MAX));
+    $target_data = explode("\n", $dumper->dump($target_storage->read($target_name), PHP_INT_MAX));
 
     // Check for new or removed files.
     if ($source_data === array('false')) {

core/lib/Drupal/Core/Config/ConfigManagerInterface.php

@@ -46,15 +46,18 @@ public function getConfigFactory();
    *   The storage to diff configuration from.
    * @param \Drupal\Core\Config\StorageInterface $target_storage
    *   The storage to diff configuration to.
-   * @param string $name
-   *   The name of the configuration object to diff.
+   * @param string $source_name
+   *   The name of the configuration object in the source storage to diff.
+   * @param string $target_name
+   *   (optional) The name of the configuration object in the target storage.
+   *   If omitted, the source name is used.
    *
    * @return core/lib/Drupal/Component/Diff
    *   A formatted string showing the difference between the two storages.
    *
    * @todo Make renderer injectable
    */
-  public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $name);
+  public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $source_name, $target_name = NULL);
 
   /**
    * Creates a configuration snapshot following a successful import.

core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php

@@ -455,4 +455,19 @@ public function importDelete($name, Config $new_config, Config $old_config) {
     return TRUE;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function importRename($old_name, Config $new_config, Config $old_config) {
+    $id = static::getIDFromConfigName($old_name, $this->entityType->getConfigPrefix());
+    $entity = $this->load($id);
+    $entity->setSyncing(TRUE);
+    $data = $new_config->get();
+    foreach ($data as $key => $value) {
+      $entity->set($key, $value);
+    }
+    $entity->save();
+    return TRUE;
+  }
+
 }

core/lib/Drupal/Core/Config/Entity/ImportableEntityStorageInterface.php

@@ -56,4 +56,16 @@ public function importUpdate($name, Config $new_config, Config $old_config);
    */
   public function importDelete($name, Config $new_config, Config $old_config);
 
+  /**
+   * Renames entities upon synchronizing configuration changes.
+   *
+   * @param string $old_name
+   *   The original name of the configuration object.
+   * @param \Drupal\Core\Config\Config $new_config
+   *   A configuration object containing the new configuration data.
+   * @param \Drupal\Core\Config\Config $old_config
+   *   A configuration object containing the old configuration data.
+   */
+  public function importRename($old_name, Config $new_config, Config $old_config);
+
 }

core/lib/Drupal/Core/Config/StorageComparer.php

@@ -100,6 +100,7 @@ public function getEmptyChangelist() {
       'create' => array(),
       'update' => array(),
       'delete' => array(),
+      'rename' => array(),
     );
   }
 
@@ -117,7 +118,7 @@ public function getChangelist($op = NULL) {
    * Adds changes to the changelist.
    *
    * @param string $op
-   *   The change operation performed. Either delete, create or update.
+   *   The change operation performed. Either delete, create, rename, or update.
    * @param array $changes
    *   Array of changes to add to the changelist.
    * @param array $sort_order
@@ -147,6 +148,7 @@ public function createChangelist() {
     $this->addChangelistCreate();
     $this->addChangelistUpdate();
     $this->addChangelistDelete();
+    $this->addChangelistRename();
     $this->sourceData = NULL;
     $this->targetData = NULL;
     return $this;
@@ -208,6 +210,80 @@ protected function addChangelistUpdate() {
     }
   }
 
+  /**
+   * Creates the rename changelist.
+   *
+   * The list of renames is created from the different source and target names
+   * with same UUID. These changes will be removed from the create and delete
+   * lists.
+   */
+  protected function addChangelistRename() {
+    // Renames will be present in both the create and delete lists.
+    $create_list = $this->getChangelist('create');
+    $delete_list = $this->getChangelist('delete');
+    if (empty($create_list) || empty($delete_list)) {
+      return;
+    }
+
+    $create_uuids = array();
+    foreach ($this->sourceData as $id => $data) {
+      if (isset($data['uuid']) && in_array($id, $create_list)) {
+        $create_uuids[$data['uuid']] = $id;
+      }
+    }
+    if (empty($create_uuids)) {
+      return;
+    }
+
+    $renames = array();
+
+    // Renames should be ordered so that dependencies are renamed last. This
+    // ensures that if there is logic in the configuration entity class to keep
+    // names in sync it will still work. $this->targetNames is in the desired
+    // order due to the use of configuration dependencies in
+    // \Drupal\Core\Config\StorageComparer::getAndSortConfigData().
+    // Node type is a good example of a configuration entity that renames other
+    // configuration when it is renamed.
+    // @see \Drupal\node\Entity\NodeType::postSave()
+    foreach ($this->targetNames as $name) {
+      $data = $this->targetData[$name];
+      if (isset($data['uuid']) && isset($create_uuids[$data['uuid']])) {
+        // Remove the item from the create list.
+        $this->removeFromChangelist('create', $create_uuids[$data['uuid']]);
+        // Remove the item from the delete list.
+        $this->removeFromChangelist('delete', $name);
+        // Create the rename name.
+        $renames[] = $this->createRenameName($name, $create_uuids[$data['uuid']]);
+      }
+    }
+
+    $this->addChangeList('rename', $renames);
+  }
+
+  /**
+   * Removes the entry from the given operation changelist for the given name.
+   *
+   * @param string $op
+   *   The changelist to act on. Either delete, create, rename or update.
+   * @param string $name
+   *   The name of the configuration to remove.
+   */
+  protected function removeFromChangelist($op, $name) {
+    $key = array_search($name, $this->changelist[$op]);
+    if ($key !== FALSE) {
+      unset($this->changelist[$op][$key]);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function moveRenameToUpdate($rename) {
+    $names = $this->extractRenameNames($rename);
+    $this->removeFromChangelist('rename', $rename);
+    $this->addChangeList('update', array($names['new_name']), $this->sourceNames);
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -220,7 +296,7 @@ public function reset() {
   /**
    * {@inheritdoc}
    */
-  public function hasChanges($ops = array('delete', 'create', 'update')) {
+  public function hasChanges($ops = array('delete', 'create', 'update', 'rename')) {
     foreach ($ops as $op) {
       if (!empty($this->changelist[$op])) {
         return TRUE;
@@ -249,4 +325,31 @@ protected function getAndSortConfigData() {
     $this->sourceNames = $dependency_manager->setData($this->sourceData)->sortAll();
   }
 
+  /**
+   * Creates a rename name from the old and new names for the object.
+   *
+   * @param string $old_name
+   *   The old configuration object name.
+   * @param string $new_name
+   *   The new configuration object name.
+   *
+   * @return string
+   *   The configuration change name that encodes both the old and the new name.
+   *
+   * @see \Drupal\Core\Config\StorageComparerInterface::extractRenameNames()
+   */
+  protected function createRenameName($name1, $name2) {
+    return $name1 . '::' . $name2;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function extractRenameNames($name) {
+    $names = explode('::', $name, 2);
+    return array(
+      'old_name' => $names[0],
+      'new_name' => $names[1],
+    );
+  }
 }

core/lib/Drupal/Core/Config/StorageComparerInterface.php

@@ -80,4 +80,30 @@ public function hasChanges($ops = array('delete', 'create', 'update'));
    */
   public function validateSiteUuid();
 
+  /**
+   * Moves a rename operation to an update.
+   *
+   * @param string $rename
+   *   The rename name, as provided by ConfigImporter::createRenameName().
+   *
+   * @see \Drupal\Core\Config\ConfigImporter::createRenameName()
+   */
+  public function moveRenameToUpdate($rename);
+
+  /**
+   * Extracts old and new configuration names from a configuration change name.
+   *
+   * @param string $name
+   *   The configuration change name, as provided by
+   *   ConfigImporter::createRenameName().
+   *
+   * @return array
+   *   An associative array of configuration names. The array keys are
+   *   'old_name' and and 'new_name' representing the old and name configuration
+   *   object names during a rename operation.
+   *
+   * @see \Drupal\Core\Config\StorageComparer::createRenameNames()
+   */
+  public function extractRenameNames($name);
+
 }

core/modules/config/config.routing.yml

@@ -7,9 +7,10 @@ config.sync:
     _permission: 'synchronize configuration'
 
 config.diff:
-  path: '/admin/config/development/configuration/sync/diff/{config_file}'
+  path: '/admin/config/development/configuration/sync/diff/{source_name}/{target_name}'
   defaults:
     _content: '\Drupal\config\Controller\ConfigController::diff'
+    target_name: NULL
   requirements:
     _permission: 'synchronize configuration'
 

core/modules/config/lib/Drupal/config/Controller/ConfigController.php

@@ -105,15 +105,15 @@ public function downloadExport() {
    * @return string
    *   Table showing a two-way diff between the active and staged configuration.
    */
-  public function diff($config_file) {
+  public function diff($source_name, $target_name = NULL) {
 
-    $diff = $this->configManager->diff($this->targetStorage, $this->sourceStorage, $config_file);
+    $diff = $this->configManager->diff($this->targetStorage, $this->sourceStorage, $source_name, $target_name);
     $formatter = new \DrupalDiffFormatter();
     $formatter->show_header = FALSE;
 
     $build = array();
 
-    $build['#title'] = t('View changes of @config_file', array('@config_file' => $config_file));
+    $build['#title'] = t('View changes of @config_file', array('@config_file' => $source_name));
     // Add the CSS for the inline diff.
     $build['#attached']['css'][] = drupal_get_path('module', 'system') . '/css/system.diff.css';
 

core/modules/config/lib/Drupal/config/Form/ConfigSync.php

@@ -184,8 +184,8 @@ public function buildForm(array $form, array &$form_state) {
     // Add the AJAX library to the form for dialog support.
     $form['#attached']['library'][] = 'core/drupal.ajax';
 
-    foreach ($storage_comparer->getChangelist() as $config_change_type => $config_files) {
-      if (empty($config_files)) {
+    foreach ($storage_comparer->getChangelist() as $config_change_type => $config_names) {
+      if (empty($config_names)) {
         continue;
       }
 
@@ -197,15 +197,19 @@ public function buildForm(array $form, array &$form_state) {
       );
       switch ($config_change_type) {
         case 'create':
-          $form[$config_change_type]['heading']['#value'] = format_plural(count($config_files), '@count new', '@count new');
+          $form[$config_change_type]['heading']['#value'] = format_plural(count($config_names), '@count new', '@count new');
           break;
 
         case 'update':
-          $form[$config_change_type]['heading']['#value'] = format_plural(count($config_files), '@count changed', '@count changed');
+          $form[$config_change_type]['heading']['#value'] = format_plural(count($config_names), '@count changed', '@count changed');
           break;
 
         case 'delete':
-          $form[$config_change_type]['heading']['#value'] = format_plural(count($config_files), '@count removed', '@count removed');
+          $form[$config_change_type]['heading']['#value'] = format_plural(count($config_names), '@count removed', '@count removed');
+          break;
+
+        case 'rename':
+          $form[$config_change_type]['heading']['#value'] = format_plural(count($config_names), '@count renamed', '@count renamed');
           break;
       }
       $form[$config_change_type]['list'] = array(
@@ -213,10 +217,18 @@ public function buildForm(array $form, array &$form_state) {
         '#header' => array('Name', 'Operations'),
       );
 
-      foreach ($config_files as $config_file) {
+      foreach ($config_names as $config_name) {
+        if ($config_change_type == 'rename') {
+          $names = $storage_comparer->extractRenameNames($config_name);
+          $href = $this->urlGenerator->getPathFromRoute('config.diff', array('source_name' => $names['old_name'], 'target_name' => $names['new_name']));
+          $config_name = $this->t('!source_name to !target_name', array('!source_name' => $names['old_name'], '!target_name' => $names['new_name']));
+        }
+        else {
+          $href = $this->urlGenerator->getPathFromRoute('config.diff', array('source_name' => $config_name));
+        }
         $links['view_diff'] = array(
           'title' => $this->t('View differences'),
-          'href' => $this->urlGenerator->getPathFromRoute('config.diff', array('config_file' => $config_file)),
+          'href' => $href,
           'attributes' => array(
             'class' => array('use-ajax'),
             'data-accepts' => 'application/vnd.drupal-modal',
@@ -226,7 +238,7 @@ public function buildForm(array $form, array &$form_state) {
           ),
         );
         $form[$config_change_type]['list']['#rows'][] = array(
-          'name' => $config_file,
+          'name' => $config_name,
           'operations' => array(
             'data' => array(
               '#type' => 'operations',

core/modules/config/lib/Drupal/config/Tests/ConfigDiffTest.php

@@ -84,6 +84,33 @@ function testDiff() {
     $this->assertEqual($diff->edits[1]->type, 'add', 'The second item in the diff is an add.');
     $this->assertFalse($diff->edits[1]->orig, format_string("The key '%add_key' does not exist in active.", array('%add_key' => $add_key)));
     $this->assertEqual($diff->edits[1]->closing[0], $add_key . ': ' . $add_data, format_string("The staging value for key '%add_key' is '%add_data'.", array('%add_key' => $add_key, '%add_data' => $add_data)));
+
+    // Test diffing a renamed config entity.
+    $test_entity_id = $this->randomName();
+    $test_entity = entity_create('config_test', array(
+      'id' => $test_entity_id,
+      'label' => $this->randomName(),
+    ));
+    $test_entity->save();
+    $data = $active->read('config_test.dynamic.' . $test_entity_id);
+    $staging->write('config_test.dynamic.' . $test_entity_id, $data);
+    $config_name = 'config_test.dynamic.' . $test_entity_id;
+    $diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name, $config_name);
+    // Prove the fields match.
+    $this->assertEqual($diff->edits[0]->type, 'copy',  'The first item in the diff is a copy.');
+    $this->assertEqual(count($diff->edits), 1, 'There is one item in the diff');
+
+    // Rename the entity.
+    $new_test_entity_id = $this->randomName();
+    $test_entity->set('id', $new_test_entity_id);
+    $test_entity->save();
+
+    $diff = \Drupal::service('config.manager')->diff($active, $staging, 'config_test.dynamic.' . $new_test_entity_id, $config_name);
+    $this->assertEqual($diff->edits[0]->type, 'change',  'The second item in the diff is a copy.');
+    $this->assertEqual($diff->edits[0]->orig, array('id: ' . $new_test_entity_id));
+    $this->assertEqual($diff->edits[0]->closing, array('id: ' . $test_entity_id));
+    $this->assertEqual($diff->edits[1]->type, 'copy',  'The second item in the diff is a copy.');
+    $this->assertEqual(count($diff->edits), 2, 'There are two items in the diff.');
   }
 
-}
\ No newline at end of file
+}

core/modules/config/lib/Drupal/config/Tests/ConfigImportRenameValidationTest.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\config\Tests\ConfigImportRenameValidationTest.
+ */
+
+namespace Drupal\config\Tests;
+
+use Drupal\Component\Utility\String;
+use Drupal\Component\Utility\Unicode;
+use Drupal\Component\Uuid\Php;
+use Drupal\Core\Config\ConfigImporter;
+use Drupal\Core\Config\ConfigImporterException;
+use Drupal\Core\Config\StorageComparer;
+use Drupal\simpletest\DrupalUnitTestBase;
+
+/**
+ * Tests validating renamed configuration in a configuration import.
+ */
+class ConfigImportRenameValidationTest extends DrupalUnitTestBase {
+
+  /**
+   * Config Importer object used for testing.
+   *
+   * @var \Drupal\Core\Config\ConfigImporter
+   */
+  protected $configImporter;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array