Chris@0: INTRODUCTION
Chris@0: ------------
Chris@0: The migrate_example_advanced module demonstrates some techniques for Drupal 8
Chris@0: migrations beyond the basics in migrate_example. It includes a group of
Chris@0: migrations with a wine theme.
Chris@0: 
Chris@0: SETUP
Chris@0: -----
Chris@0: To demonstrate XML migrations as realistically as possible, the setup module
Chris@0: provides the source data as REST services. So the migrations' references to these
Chris@0: services can be set up accurately, if you install migrate_example_advanced via
Chris@0: drush be sure to use the --uri parameter, e.g.
Chris@0: 
Chris@0: drush en -y migrate_example_advanced --uri=http://d8.local:8083/
Chris@0: 
Chris@0: THE WINE SITE
Chris@0: -------------
Chris@0: In this scenario, we have a wine aficionado site which stores data in SQL tables
Chris@0: as well is pulling in additional data from XML services.
Chris@0: 
Chris@0: To make the example as simple as to run as possible, the SQL data is placed in
Chris@0: tables directly in your Drupal database - in most real-world scenarios, your
Chris@0: source data will be in an external database. The migrate_example_advanced_setup
Chris@0: submodule creates and populates these tables, as well as configuring your Drupal
Chris@0: 8 site (creating node types, vocabularies, fields, etc.) to receive the data,
Chris@0: and providing service endpoints for XML data.
Chris@0: 
Chris@0: STRUCTURE
Chris@0: ---------
Chris@0: As with most custom migrations, there are two primary components to this
Chris@0: example:
Chris@0: 
Chris@0: 1. Migration configuration, in the config/install directory. These YAML files
Chris@0:    describe the migration process and provide the mappings from the source data
Chris@0:    to Drupal's destination entities.
Chris@0: 
Chris@0: 2. Source plugins, in src/Plugin/migrate/source. These are referenced from the
Chris@0:    configuration files, and provide the source data to the migration processing
Chris@0:    pipeline, as well as manipulating that data where necessary to put it into
Chris@0:    a canonical form for migrations.
Chris@0: 
Chris@0: UNDERSTANDING THE MIGRATIONS
Chris@0: ----------------------------
Chris@0: Basic techniques demonstrated in the migrate_example module are not rehashed
Chris@0: here - it is expected that if you are learning Drupal 8 migration, you will
Chris@0: study and understand those examples first, and use migrate_example_advanced to
Chris@0: learn about specific techniques beyond those basics. This example doesn't have
Chris@0: the narrative form of migrate_example - it's more of a grab-bag demonstrating
Chris@0: varous features, and is more of a reference for, say, copying the code to set
Chris@0: up an XML migration. An index of things demonstrated by this module:
Chris@0: 
Chris@0: Multiple vocabularies populated in one migration
Chris@0: ------------------------------------------------
Chris@0: See migrate_plus.migration.wine_terms.yml.
Chris@0: 
Chris@0: Importing from XML services
Chris@0: ---------------------------
Chris@0: See migrate_plus.migration.wine_role_xml.yml.