This document discusses building a non-blocking REST API in Play Framework and Scala in less than 30 minutes. It will cover creating a simple REST API for managing work hours using ScalikeJDBC for asynchronous database access. The API will include models for Employee, Project, and TimeEntry connected to a relational database, allowing CRUD operations on time entries. It also discusses best practices for REST APIs like adhering to Fielding constraints and using JSON for request/response bodies.

1. Building a non-blocking
REST API
in less than 30 minutes
Thomas Meijers - @ItsMeijers

2. About me
Thomas Meijers @ItsMeijers
Lunatech
Student
Play Framework Amsterdam @ItsMeijers

3. Experience with Play?
Play Framework Amsterdam @ItsMeijers

4. Experience with Scala?
Play Framework Amsterdam @ItsMeijers

5. Content
What are we building?
REST Refresh
Persistence
Building the API
ScalikeJDBC in Action
Fielding constraints
Recommendation
Play Framework Amsterdam @ItsMeijers

6. What are we building?
Simple non-blocking REST API for managing work hours
Consists of 3 models connected to a relational database
(CRUD)
Employee
Project
TimeEntry
Play Framework Amsterdam @ItsMeijers

7. What are we building?
Play Framework Amsterdam @ItsMeijers

8. REST & The Fielding Constraints
0. Client Server
1. Statelessness
2. Cacheable
3. Layered system
4. Uniform interface
5. Code on demand (optional)
Play Framework Amsterdam @ItsMeijers

9. Persistence
Relational Databases
Slick (Non-blocking)
Anorm
ScalikeJDBC
ScalikeJDBC-Async (Non-blocking)
Play Framework Amsterdam @ItsMeijers

10. ScalikeJDBC-Async
Tidy SQL-based DB access library for Scala
Cool QueryDSL (EDSL)
Play Framework support!
Non-blocking
* Experimental (although production ready)
Play Framework Amsterdam @ItsMeijers

11. Why Non-Blocking?
Play Framework Amsterdam @ItsMeijers

12. Building the API
Play Framework Amsterdam @ItsMeijers
What do we
want?
When do we want
it?
Code
!
Now
!

13. Dependencies in build.sbt
Play Framework Amsterdam @ItsMeijers

14. Configuration
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Application.conf
play.plugins

15. Creating the URIs
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16. ScalikeJDBC-Async
Play Framework Amsterdam @ItsMeijers

17. ScalikeJDBC-Async Mapping
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18. ScalikeJDBC-Async Mapping
Play Framework Amsterdam @ItsMeijers

19. Find a TimeEntry
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20. Find a TimeEntry by Employee
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21. Creating a TimeEntry
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22. Deleting a TimeEntry
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23. Representation Class
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Send and retrieve from the client Send and retrieve from DB

24. JSON Parsing
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25. JSON helper functions
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26. API Index - GET /api
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27. GET /api/time-entries
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28. GET /api/time-entries/:id
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29. POST /api/time-entries
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30. PUT /api/time-entries/:id
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31. DELETE /api/time-entries/:id
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32. ScalikeJDBC-Async
In Action
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33. Fielding Constraints
0. Client Server
1. Statelessness
2. Cacheable
3. Layered system
4. Uniform interface
5. Code on demand (optional)
Play Framework Amsterdam @ItsMeijers

34. github.com/ThomasMeijers/NonBlocking
Complete API
Play Framework Amsterdam @ItsMeijers

35. Use a hypermedia format
HAL - github.com/restfulscala/HALselhof
Siren - github.com/yetu/siren-scala
Documentation: Swagger.io
Slick
Monad Transformers
Recommendations
Play Framework Amsterdam @ItsMeijers

36. Thomas Meijers - @ItsMeijers
Thank you
Questions?
Lunatech is hiring!
val yourName: Future[AwesomeJob] = withSQL{ select.job.from(Lunatech) }