Chris@0: <?php
Chris@0: 
Chris@0: /**
Chris@0:  * @file
Chris@0:  * Hooks provided by the Migrate module.
Chris@0:  */
Chris@0: 
Chris@0: use Drupal\migrate\Plugin\MigrationInterface;
Chris@0: use Drupal\migrate\Plugin\MigrateSourceInterface;
Chris@0: use Drupal\migrate\Row;
Chris@0: 
Chris@0: /**
Chris@14:  * @defgroup migration Migrate API
Chris@0:  * @{
Chris@14:  * Overview of the Migrate API, which migrates data into Drupal.
Chris@0:  *
Chris@14:  * @section overview Overview of a migration
Chris@0:  * Migration is an
Chris@0:  * @link http://wikipedia.org/wiki/Extract,_transform,_load Extract, Transform, Load @endlink
Chris@14:  * (ETL) process. In the Drupal Migrate API, the extract phase is called
Chris@14:  * 'source', the transform phase is called 'process', and the load phase is
Chris@14:  * called 'destination'. It is important to understand that the term 'load' in
Chris@14:  * ETL refers to loading data into the storage while in a typical Drupal context
Chris@14:  * the term 'load' refers to loading data from storage.
Chris@0:  *
Chris@0:  * In the source phase, a set of data, called the row, is retrieved from the
Chris@14:  * data source. The data can be migrated from a database, loaded from a file
Chris@14:  * (for example CSV, JSON or XML) or fetched from a web service (for example RSS
Chris@14:  * or REST). The row is sent to the process phase where it is transformed as
Chris@14:  * needed or marked to be skipped. Processing can also determine if a 'stub'
Chris@14:  * needs to be created. For example, if a term has a parent term which hasn't
Chris@14:  * been migrated yet, a stub term is created so that the parent relation can be
Chris@14:  * established, and the stub is updated at a later point. After processing, the
Chris@14:  * transformed row is passed to the destination phase where it is loaded (saved)
Chris@14:  * into the target Drupal site.
Chris@0:  *
Chris@14:  * Migrate API uses the Drupal plugin system for many different purposes. Most
Chris@14:  * importantly, the overall ETL process is defined as a migration plugin and the
Chris@14:  * three phases (source, process and destination) have their own plugin types.
Chris@0:  *
Chris@14:  * @section sec_migrations Migrate API migration plugins
Chris@0:  * Migration plugin definitions are stored in a module's 'migrations' directory.
Chris@14:  * The plugin class is \Drupal\migrate\Plugin\Migration, with interface
Chris@0:  * \Drupal\migrate\Plugin\MigrationInterface. Migration plugins are managed by
Chris@0:  * the \Drupal\migrate\Plugin\MigrationPluginManager class. Migration plugins
Chris@0:  * are only available if the providers of their source plugins are installed.
Chris@0:  *
Chris@14:  * @link https://www.drupal.org/docs/8/api/migrate-api/migrate-destination-plugins-examples Example migrations in Migrate API handbook. @endlink
Chris@14:  *
Chris@14:  * @section sec_source Migrate API source plugins
Chris@14:  * Migrate API source plugins implement
Chris@0:  * \Drupal\migrate\Plugin\MigrateSourceInterface and usually extend
Chris@0:  * \Drupal\migrate\Plugin\migrate\source\SourcePluginBase. They are annotated
Chris@14:  * with \Drupal\migrate\Annotation\MigrateSource annotation and must be in
Chris@14:  * namespace subdirectory 'Plugin\migrate\source' under the namespace of the
Chris@14:  * module that defines them. Migrate API source plugins are managed by the
Chris@14:  * \Drupal\migrate\Plugin\MigrateSourcePluginManager class.
Chris@0:  *
Chris@14:  * @link https://api.drupal.org/api/drupal/namespace/Drupal!migrate!Plugin!migrate!source List of source plugins provided by the core Migrate module. @endlink
Chris@14:  * @link https://www.drupal.org/docs/8/api/migrate-api/migrate-source-plugins Core and contributed source plugin usage examples in Migrate API handbook. @endlink
Chris@14:  *
Chris@14:  * @section sec_process Migrate API process plugins
Chris@14:  * Migrate API process plugins implement
Chris@0:  * \Drupal\migrate\Plugin\MigrateProcessInterface and usually extend
Chris@14:  * \Drupal\migrate\ProcessPluginBase. They are annotated with
Chris@14:  * \Drupal\migrate\Annotation\MigrateProcessPlugin annotation and must be in
Chris@14:  * namespace subdirectory 'Plugin\migrate\process' under the namespace of the
Chris@14:  * module that defines them. Migrate API process plugins are managed by the
Chris@14:  * \Drupal\migrate\Plugin\MigratePluginManager class.
Chris@0:  *
Chris@14:  * @link https://api.drupal.org/api/drupal/namespace/Drupal!migrate!Plugin!migrate!process List of process plugins for common operations provided by the core Migrate module. @endlink
Chris@14:  *
Chris@14:  * @section sec_destination Migrate API destination plugins
Chris@14:  * Migrate API destination plugins implement
Chris@0:  * \Drupal\migrate\Plugin\MigrateDestinationInterface and usually extend
Chris@0:  * \Drupal\migrate\Plugin\migrate\destination\DestinationBase. They are
Chris@14:  * annotated with \Drupal\migrate\Annotation\MigrateDestination annotation and
Chris@14:  * must be in namespace subdirectory 'Plugin\migrate\destination' under the
Chris@14:  * namespace of the module that defines them. Migrate API destination plugins
Chris@0:  * are managed by the \Drupal\migrate\Plugin\MigrateDestinationPluginManager
Chris@14:  * class.
Chris@0:  *
Chris@14:  * @link https://api.drupal.org/api/drupal/namespace/Drupal!migrate!Plugin!migrate!destination List of destination plugins for Drupal configuration and content entities provided by the core Migrate module. @endlink
Chris@0:  *
Chris@14:  * @section sec_more_info Documentation handbooks
Chris@14:  * @link https://www.drupal.org/docs/8/api/migrate-api Migrate API handbook. @endlink
Chris@14:  * @link https://www.drupal.org/docs/8/upgrade Upgrading to Drupal 8 handbook. @endlink
Chris@0:  * @}
Chris@0:  */
Chris@0: 
Chris@0: /**
Chris@0:  * @addtogroup hooks
Chris@0:  * @{
Chris@0:  */
Chris@0: 
Chris@0: /**
Chris@0:  * Allows adding data to a row before processing it.
Chris@0:  *
Chris@0:  * For example, filter module used to store filter format settings in the
Chris@0:  * variables table which now needs to be inside the filter format config
Chris@0:  * file. So, it needs to be added here.
Chris@0:  *
Chris@0:  * hook_migrate_MIGRATION_ID_prepare_row() is also available.
Chris@0:  *
Chris@14:  * @param \Drupal\migrate\Row $row
Chris@14:  *   The row being imported.
Chris@14:  * @param \Drupal\migrate\Plugin\MigrateSourceInterface $source
Chris@14:  *   The source migration.
Chris@14:  * @param \Drupal\migrate\Plugin\MigrationInterface $migration
Chris@14:  *   The current migration.
Chris@14:  *
Chris@0:  * @ingroup migration
Chris@0:  */
Chris@0: function hook_migrate_prepare_row(Row $row, MigrateSourceInterface $source, MigrationInterface $migration) {
Chris@0:   if ($migration->id() == 'd6_filter_formats') {
Chris@0:     $value = $source->getDatabase()->query('SELECT value FROM {variable} WHERE name = :name', [':name' => 'mymodule_filter_foo_' . $row->getSourceProperty('format')])->fetchField();
Chris@0:     if ($value) {
Chris@0:       $row->setSourceProperty('settings:mymodule:foo', unserialize($value));
Chris@0:     }
Chris@0:   }
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@14:  * Allows adding data to a row for a migration with the specified ID.
Chris@14:  *
Chris@14:  * This provides the same functionality as hook_migrate_prepare_row() but
Chris@14:  * removes the need to check the value of $migration->id().
Chris@14:  *
Chris@14:  * @param \Drupal\migrate\Row $row
Chris@14:  *   The row being imported.
Chris@14:  * @param \Drupal\migrate\Plugin\MigrateSourceInterface $source
Chris@14:  *   The source migration.
Chris@14:  * @param \Drupal\migrate\Plugin\MigrationInterface $migration
Chris@14:  *   The current migration.
Chris@14:  *
Chris@14:  * @ingroup migration
Chris@14:  */
Chris@14: function hook_migrate_MIGRATION_ID_prepare_row(Row $row, MigrateSourceInterface $source, MigrationInterface $migration) {
Chris@14:   $value = $source->getDatabase()->query('SELECT value FROM {variable} WHERE name = :name', [':name' => 'mymodule_filter_foo_' . $row->getSourceProperty('format')])->fetchField();
Chris@14:   if ($value) {
Chris@14:     $row->setSourceProperty('settings:mymodule:foo', unserialize($value));
Chris@14:   }
Chris@14: }
Chris@14: 
Chris@14: /**
Chris@0:  * Allows altering the list of discovered migration plugins.
Chris@0:  *
Chris@0:  * Modules are able to alter specific migrations structures or even remove or
Chris@0:  * append additional migrations to the discovery. For example, this
Chris@0:  * implementation filters out Drupal 6 migrations from the discovered migration
Chris@0:  * list. This is done by checking the migration tags.
Chris@0:  *
Chris@0:  * @param array[] $migrations
Chris@0:  *   An associative array of migrations keyed by migration ID. Each value is the
Chris@0:  *   migration array, obtained by decoding the migration YAML file and enriched
Chris@0:  *   with some meta information added during discovery phase, like migration
Chris@0:  *   'class', 'provider' or '_discovered_file_path'.
Chris@0:  *
Chris@0:  * @ingroup migration
Chris@0:  */
Chris@0: function hook_migration_plugins_alter(array &$migrations) {
Chris@0:   $migrations = array_filter($migrations, function (array $migration) {
Chris@0:     $tags = isset($migration['migration_tags']) ? (array) $migration['migration_tags'] : [];
Chris@0:     return !in_array('Drupal 6', $tags);
Chris@0:   });
Chris@0: }
Chris@0: 
Chris@0: /**
Chris@0:  * @} End of "addtogroup hooks".
Chris@0:  */