diff core/modules/migrate/migrate.api.php @ 0:4c8ae668cc8c

Initial import (non-working)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/modules/migrate/migrate.api.php	Wed Nov 29 16:09:58 2017 +0000
@@ -0,0 +1,138 @@
+<?php
+
+/**
+ * @file
+ * Hooks provided by the Migrate module.
+ */
+
+use Drupal\migrate\Plugin\MigrationInterface;
+use Drupal\migrate\Plugin\MigrateSourceInterface;
+use Drupal\migrate\Row;
+
+/**
+ * @defgroup migration Migration API
+ * @{
+ * Overview of the Migration API, which migrates data into Drupal.
+ *
+ * @section overview Overview of migration
+ * Migration is an
+ * @link http://wikipedia.org/wiki/Extract,_transform,_load Extract, Transform, Load @endlink
+ * (ETL) process. In the Drupal migration API the extract phase is called
+ * "source", the transform phase is called "process", and the load phase is
+ * called "destination". It is important to understand that the "load" in ETL
+ * means to load data into storage, while traditionally Drupal uses "load" to
+ * mean load data from storage into memory.
+ *
+ * In the source phase, a set of data, called the row, is retrieved from the
+ * data source, typically a database but it can be a CSV, JSON or XML file. The
+ * row is sent to the process phase where it is transformed as needed by the
+ * destination, or marked to be skipped. Processing can also determine that a
+ * stub needs to be created, for example, if a term has a parent term that does
+ * not yet exist. After processing the transformed row is passed to the
+ * destination phase where it is loaded (saved) into the Drupal 8 site.
+ *
+ * The ETL process is configured by the migration plugin. The different phases:
+ * source, process, and destination are also plugins, and are managed by the
+ * Migration plugin. So there are four types of plugins in the migration
+ * process: migration, source, process and destination.
+ *
+ * @section sec_migrations Migration plugins
+ * Migration plugin definitions are stored in a module's 'migrations' directory.
+ * For backwards compatibility we also scan the 'migration_templates' directory.
+ * Examples of migration plugin definitions can be found in
+ * 'core/modules/action/migration_templates'. The plugin class is
+ * \Drupal\migrate\Plugin\Migration, with interface
+ * \Drupal\migrate\Plugin\MigrationInterface. Migration plugins are managed by
+ * the \Drupal\migrate\Plugin\MigrationPluginManager class. Migration plugins
+ * are only available if the providers of their source plugins are installed.
+ *
+ * @section sec_source Source plugins
+ * Migration source plugins implement
+ * \Drupal\migrate\Plugin\MigrateSourceInterface and usually extend
+ * \Drupal\migrate\Plugin\migrate\source\SourcePluginBase. They are annotated
+ * with \Drupal\migrate\Annotation\MigrateSource annotation, and must be in
+ * namespace subdirectory Plugin\migrate\source under the namespace of the
+ * module that defines them. Migration source plugins are managed by the
+ * \Drupal\migrate\Plugin\MigrateSourcePluginManager class. Source plugin
+ * providers are determined by their and their parents namespaces.
+ *
+ * @section sec_process Process plugins
+ * Migration process plugins implement
+ * \Drupal\migrate\Plugin\MigrateProcessInterface and usually extend
+ * \Drupal\migrate\ProcessPluginBase. They are annotated
+ * with \Drupal\migrate\Annotation\MigrateProcessPlugin annotation, and must be
+ * in namespace subdirectory Plugin\migrate\process under the namespace of the
+ * module that defines them. Migration process plugins are managed by the
+ * \Drupal\migrate\Plugin\MigratePluginManager class. The Migrate module
+ * provides process plugins for common operations (setting default values,
+ * mapping values, etc.).
+ *
+ * @section sec_destination Destination plugins
+ * Migration destination plugins implement
+ * \Drupal\migrate\Plugin\MigrateDestinationInterface and usually extend
+ * \Drupal\migrate\Plugin\migrate\destination\DestinationBase. They are
+ * annotated with \Drupal\migrate\Annotation\MigrateDestination annotation, and
+ * must be in namespace subdirectory Plugin\migrate\destination under the
+ * namespace of the module that defines them. Migration destination plugins
+ * are managed by the \Drupal\migrate\Plugin\MigrateDestinationPluginManager
+ * class. The Migrate module provides destination plugins for Drupal core
+ * objects (configuration and entity).
+ *
+ * @section sec_more_info More information
+ * @link https://www.drupal.org/node/2127611 Migration API documentation. @endlink
+ *
+ * @see update_api
+ * @}
+ */
+
+/**
+ * @addtogroup hooks
+ * @{
+ */
+
+/**
+ * Allows adding data to a row before processing it.
+ *
+ * For example, filter module used to store filter format settings in the
+ * variables table which now needs to be inside the filter format config
+ * file. So, it needs to be added here.
+ *
+ * hook_migrate_MIGRATION_ID_prepare_row() is also available.
+ *
+ * @ingroup migration
+ */
+function hook_migrate_prepare_row(Row $row, MigrateSourceInterface $source, MigrationInterface $migration) {
+  if ($migration->id() == 'd6_filter_formats') {
+    $value = $source->getDatabase()->query('SELECT value FROM {variable} WHERE name = :name', [':name' => 'mymodule_filter_foo_' . $row->getSourceProperty('format')])->fetchField();
+    if ($value) {
+      $row->setSourceProperty('settings:mymodule:foo', unserialize($value));
+    }
+  }
+}
+
+/**
+ * Allows altering the list of discovered migration plugins.
+ *
+ * Modules are able to alter specific migrations structures or even remove or
+ * append additional migrations to the discovery. For example, this
+ * implementation filters out Drupal 6 migrations from the discovered migration
+ * list. This is done by checking the migration tags.
+ *
+ * @param array[] $migrations
+ *   An associative array of migrations keyed by migration ID. Each value is the
+ *   migration array, obtained by decoding the migration YAML file and enriched
+ *   with some meta information added during discovery phase, like migration
+ *   'class', 'provider' or '_discovered_file_path'.
+ *
+ * @ingroup migration
+ */
+function hook_migration_plugins_alter(array &$migrations) {
+  $migrations = array_filter($migrations, function (array $migration) {
+    $tags = isset($migration['migration_tags']) ? (array) $migration['migration_tags'] : [];
+    return !in_array('Drupal 6', $tags);
+  });
+}
+
+/**
+ * @} End of "addtogroup hooks".
+ */