Sometimes you want to upgrade to Drupal 8, but need more fine-grained control than the all-or-nothing system provided by the Migrate Drupal, and Migrate Drupal UI modules in core. This week we're adding five new tutorials to our Drupal 8 Migration Guide that walk through the process of creating a custom Drupal-to-Drupal migration, allowing you to fine-tune every aspect of the migration from a previous version of Drupal into Drupal 8.
Earlier this year we wrote about this process on our blog. The post was quite popular, and readers asked lots of really great questions about the process we used. We've done our best to answer those questions, and we heard you when you said that this was an important skill to learn. That blog post covers the basics, but if you want to know more about the details, and really understand what's going on check out these new tutorials:
- Custom Drupal-to-Drupal Migrations
- Create Migrations from Core Templates
- Export Migration Configuration Entities into a Module
- Customize an Existing Source Plugin
As an example we'll walk through how we migrated the content of just the blog section of the Drupalize.Me website as well as related users and taxonomy terms. We'll use the Migrate Plus, and Migrate Upgrade modules to create migration configuration entities and customize the generated migrations in order to limit the scope of what is migrated. We'll create a module that can contain our custom migrations so it's easier to collaborate with others on development. And finally we'll learn to use features like
hook_migrate_prepare_row() to further tweak the migration process.
Even if you're not performing a custom Drupal-to-Drupal migration reading through these tutorials will help you better understand the relationship between migration templates and migration configuration entities. They provide some good examples of the types of problems you can solve with custom source plugins and implementations of
hook_migrate_prepare_row(). This is a must for anyone wanting to create Drupal 8 migrations.
Let us know what else you want to know
We want to ensure that our Drupal 8 Migration Guide is complete, and that means making sure we're helping you learn how to accomplish everything you need to in order to perform a successful migration. Let us know what you think we might be missing by leaving a comment here or sending us an email.