1. REST & ASP.NET Web API
@JefClaes

2. Thanks to the sponsors

3. about/jefclaes
@jefclaes
http://jefclaes.be

4. REST

5. The acronym
REpresentational State Transfer

6. REST is NOT...
• ‘Webservices using JSON’
• A protocol
• A design pattern

7. REST is..
“An architectural style for building
distributed hypermedia systems.”

8. In theory...
REST isn’t limited to a
single message protocol.

9. But in practice...
It’s all about HTTP.

10. So now you wonder..
Haven’t we been successfully building
web services using SOAP and HTTP
for over 10 years ?

11. BASIC CONCEPTS

12. Resources
• An entity, item, or just a thing you want to expose.
• REST is Resource Oriented.

13. Resources

14. Resources

15. Resources

16. Resources

17. Identifiers
Something that identifies a resource.
ID: 1
URI: http://batman.com/api/batresource/1

18. Representations
View on a resource’s state at an instant in time.
XML: JSON: Other:
<BatResource> { • Images
<Id>1</Id> "Id":"1", • CSV
<Description> "Description":"Bataran • Custom
Batarang g", • ...
</Description> "Quantity":1
<Quantity>1</Quantity> }
</BatResource>

19. Verbs
Actions on a resource.
Create Read Update Delete
POST GET PUT DELETE

20. Hypermedia
HATEOAS: Hypermedia as the engine of application state
Linking your API together
{
"Id":"1",
"Description":"Batarang",
“Quantity":1,
“Links":
{
"Rel":"Next",
"Href":"http://localhost:8080/api/batresource/2"
}
}

21. HypeRRRRRRRmedia
• Relations
• Embedded resources
• Reference data
• Redistribution of effort
• Reduction of payload size
• Reflow
• Restriction of functionality

22. Architecture of the WEB
ARCHITECTURAL VALUES

23. Scalability and performance
Yes, text-based, synchronous, request-response
can be performant.
• Stateless
• Caching

24. Loose coupling
• No transactions
• No state
• No guarantees
• HATEOAS
• No specific technology stack

25. Consistency and Uniformity
Everybody knows how to use HTTP
–Constraints
–Well understood semantics

26. LEFT-OVERS

27. Richardson’s Maturity Model
Level 0: POX
Level 1: Resources
Level 2: HTTP verbs
Level 3: Hypermedia

28. ASP.NET WEBAPI

29. What?
.NET HTTP framework
(4.0)
for building RESTful services.

30. When?
• HTTP Services (WCF)
• AJAX back-ends

31. The server

32. Options
• WebHost
– ASP.NET MVC: Click, click, click
• SelfHost

33. Starting

34. Mapping Web API to
REST concepts

35. A resource

36. A resource

37. Identifiers

38. Identifiers

39. Verbs

40. Verbs

41. Representations

42. Representations
application/json
text/xml

43. Representations

44. Hypermedia

45. Hypermedia

46. The Client

47. Package
Microsoft.AspNet.WebApi.Client

48. Verbs and asynchrony

49. Summary
• REST
– Concepts
– Architectual values
– Left overs
• ASP.NET Web API
– Server
– Client

50. There is more
Slides and source on http://jefclaes.be
Extensibility?
• Next session (Raffaele Rialdi)
• http://github.com/JefClaes/aspnet-webapi-samples-tunisia

51. Please rate this session
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