Slides for the workshop Services in Drupal 8 by Wizzlern for the DrupalJam 2017.

2. More code, less spaghetti
Using services to structure your code.
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3. About Wizzlern
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4. Wizzlern
‣ 100% Drupal
‣ Drupal training and consultancy
‣ Front-, backend-development
‣ Dev-ops and editorial
‣ Advanced subjects
‣ Since 2009
‣ Active in the Drupal community
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5. Wizzlern trainingen
‣ Backend track
‣ Basistraining (2d)
‣ Drupal architecture (2d)
‣ Drupal 8 development (3d)
‣ Drupal deployment (1d)
‣ Frontend track
‣ Basistraining (2d)
‣ Theme development (2d)
‣ Drupal deployment (1d)
‣ Systeembeheer
‣ Basistraining (1d)
‣ Functioneel beheer (2d)
‣ Content management
‣ Basistraining (1d)
‣ Redactie (1d)
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6. Program
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7. Program
‣ Why services
‣ About the exercises
‣ Services
‣ Refactoring code
‣ When to use services
‣ Alternatives
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8. Why services
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9. Why using a service?
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10. Why services
‣ A solution to organise your code.
‣ Drupal 8 brings new possibilities, lets explore
them!
‣ For the beauty of the code.
‣ Service are unit-testable.
‣ Better code structure
= easier maintenance & scaling = cheaper.
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11. About the exercises
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12. Exercises use case
‣ A news website
‣ Content
‣ News (nodes)
‣ News categories
(terms)
‣ Front page
‣ Popular- & Tech
news (block)
‣ News page
‣ News content
‣ Related news
(extra field)
‣ Latest news (block)
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13. Exercise code
‣ https://github.com/wizzlern/drupal-service-structure
‣ starter-kit
‣ Drupal core + install profile + modules
‣ exercises
‣ One folder per exercise. Detail description + code.
‣ Additional code code_snippets.php
‣ final-result
‣ Working code. For learning by reading or copy/paste.
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14. Exercise
‣ Get familiar with the News custom code in:
‣ Plugin/Block/WeNewsRecentNews
‣ Plugin/Block/WeNewsRecentNewsByGroup
‣ Plugin/ExtraField/RelatedNews
‣ we_news.module: we_news_cron()
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15. Services
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16. Services
‣ Service = Software design pattern.
‣ Service = Provides a globally usable
functionality.
‣ Examples: Database, URL generator,
TranslationManager
‣ Advantages: Decoupled, Lazy loading.
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17. Services
‣ Better structure, scaling and maintenance.
‣ Breaking code into smaller chunks makes it
more self-documenting.
‣ Let go of your procedural habits.
‣ Give it an interface!
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18. Services
‣ Use a service for:
‣ Business logic from hooks
‣ Business logic from preprocess
‣ Business logic for custom content entities
‣ Helpers that require other service.
‣ Repeated or similar business logic from blocks,
controllers, plugins, etc.
‣ For independent logic
‣ API communication, Larger logic structures, etc.
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19. As a developer I want to structure the code of the Recent
news block.
Exercise
‣ Are there parts in WeNewsRecentNews that can be
moved to a service?
‣ Create a service that contains business logic related
to the News content type.
‣ Details in: 01-recent-news/exercise.md
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20. Service layers
‣ Grouping services into functional layers
reduces the impact of change.
‣ A service should contain only a specific type
of logic. Example: either reusable or process-
specific logic.
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21. More structures
‣ Constants defined in an interface
‣ Decorator
‣ Trait
‣ A class that groups static helper methods
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22. As a developer I want to structure the code of the News by
category group block.
Exercise
‣ What parts in WeNewsRecentNewsByGroup that can
be moved to a service?
‣ Create a service that contains business logic related
to the News Category vocabulary.
‣ Details in: 02-news-by-group/exercise.md
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23. As a developer I want to structure code of the Related
news extra field.
Exercise
‣ Are there parts in the code that can be moved to a
service?
‣ Can we re-use an existing service or do we create a
new one?
‣ Details in: 03-related-news/exercise.md
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24. As a developer I want to structure code of the news cron
task.
Exercise
‣ Are there parts in we_news_cron() that can be moved
to a service?
‣ Create a service that contains business logic related
to the news archive.
‣ Details in: 04-cron-service/exercise.md
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25. Summary
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26. Summary
‣ Structure for maintainability.
‣ Larger projects require more structure.
‣ Group related business logic.
‣ Services and interfaces are one of the tools.
Ask yourself what pattern matches best.
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27. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
http://wizzlern.nl
@wizzlern
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