DCM-2018 Writing Dynamic Migrations

Drupalcamp Mumbai 2018
Writing Dynamic Migrations

Transcript

1. 1 axelerant.com How to write dynamic migration Mohit Aghera, Mitesh Patel
2. 2 axelerant.com About Us Mohit Aghera - Back-end developer @Axelerant - Drupal.org: mohit_aghera - Twitter: @mohit_rocks Mitesh Patel - Back-end developer @Axelerant - Known as @miteshmap over internet.
3. 3 axelerant.com Dynamic Migrations • What are dynamic migrations ? • Why do we need ?
4. 4 axelerant.com Migrations : Recap
5. 5 axelerant.com Migrations: A brief introduction What Migrate API Provides: • Migrate Data from source to destination • Keeps track of record of migrated data • Provides framework for writing migrations
6. 6 axelerant.com Migration Plugins • Source Plugins • Process Plugins • Destination Plugins
7. 7 axelerant.com Migration Flow
8. 8 axelerant.com Understanding Derivatives • Drupal 7 has “_info()” hooks • Wonder how do we generate multiple blocks with single block plugin ? • Drupal 8 has “Derivatives” • Allows to generate instances dynamically
9. 9 axelerant.com How Derivatives works ? • Plugin manager uses “Discovery” mechanism • “DerivativeDiscoveryDecorator” decorator class
10. 10 axelerant.com Define along with Plugin
11. 11 axelerant.com Deriver Implementation SystemMenuBlock Deriver implementation:
12. 12 axelerant.com Understanding Derivers Notable Examples: • SystemMenuBlock • BlockContentBlock • LanguageBlock And many more..
13. 13 axelerant.com Possible approaches for migration • Migration templates • Config Entities
14. 14 axelerant.com Migration as Configuration entities • Similar to any configurations • Resides in [module]/config directory • Typically names are given like “migrate.migration.node_page.yml”
15. 15 axelerant.com Migration as Configuration entities Advantages: • Easy to write and run • No need to write specific logic to run unlike migration templates Disadvantages: • Not much flexible • Hard to change runtime • Dynamic migration generation is not possible • Can’t generate based on user inputs
16. 16 axelerant.com Migration as templates • Resides in [module]/migration_templates directory • Names could match the migration id • Typically names are given like “node_page.yml”
17. 17 axelerant.com Migration as templates Advantages: • Much more flexible than configuration entities for each variation • Easy to change runtime • Ability to generate dynamic migration using reusable templates
18. 18 axelerant.com Derivers for Migration • Works as a derivative for new migrations • Helps to create migrations dynamically • Extends DeriverBase class.
19. 19 axelerant.com Writing Derivers • Implement getDerivativeDefinitions() and write your logic.
20. 20 axelerant.com Using Derivers Specify in migration template file.
21. 21 axelerant.com Running migration
22. 22 axelerant.com Use cases • Migrating large amount of sites with similar architecture but different languages in each site (our use case, https://github.com/miteshmap/drupal_migration_demo) • Core: Migrating D7 to D8 • Core: Migrating Workbench Moderation to Content Moderation (https://www.drupal.org/project/wbm2cm) • Migrating sites from Magento for instance with different attributes for each site • And many more...
23. 23 axelerant.com Thank you … for being here and allowing us to contribute and share our knowledge To summarise… • We discussed how to make migrations more dynamic and less painful • We saw an example of how to write derivers • We saw advantages of doing it, it is done in Core and many contrib modules already
24. 24 axelerant.com References Migration API : https://www.drupal.org/docs/8/api/migrate-api/migrate-api-overview Reference module : https://github.com/mohit-rocks/drupalcamp-goa