Hypermedia APIs with Webmachine and ROAR

Building hypermedia APIs with Webmachine and ROAR

Transcript

1. Hypermedia APIs Hypermedia APIs Webmachine & ROAR 1 Larry Staton Jr. : @statonjr 1 Wednesday, 14 November 12
2. Hypermedia APIs Assumptions 2 2 Wednesday, 14 November 12
3. Hypermedia APIs REST 3 3 Wednesday, 14 November 12
4. Hypermedia APIs 4 Constraint Promotes Tradeoff client-server UI Portability Simplified server stateless Scalability Reliability Efficiency non-shared caching Reduced latency Efficiency Scalability Reliability uniform interface Independent Evolution Decoupled implementation Efficiency layered system Scalability Simplified clients Higher Latency code-on-demand Extensibility Simplified clients Visibility 4 Wednesday, 14 November 12
5. Hypermedia APIs 5 Uniform Interface 5 Wednesday, 14 November 12
6. Hypermedia APIs HTTP 6 6 Wednesday, 14 November 12
7. Hypermedia APIs 7 Constraint Promotes Tradeoff client-server UI Portability Simplified server stateless Scalability Reliability Efficiency non-shared caching Reduced latency Efficiency Scalability Reliability uniform interface Independent Evolution Decoupled implementation Efficiency layered system Scalability Simplified clients Higher Latency code-on-demand Extensibility Simplified clients Visibility 7 Wednesday, 14 November 12
8. Hypermedia APIs “REST APIs must be hypertext-driven” 8 — Fielding, 2009! 8 Wednesday, 14 November 12
9. Hypermedia APIs 9 Richardson Maturity Model 9 Wednesday, 14 November 12
10. Hypermedia APIs Hypermedia 10 10 Wednesday, 14 November 12
11. Hypermedia APIs Media Types 11 11 Wednesday, 14 November 12
12. Hypermedia APIs 12 Media Type Hypermedia? text/html application/atom+xml application/json application/hal+json 12 Wednesday, 14 November 12
13. Hypermedia APIs HTTP 13 13 Wednesday, 14 November 12
14. Hypermedia APIs 14 14 Wednesday, 14 November 12
15. Hypermedia APIs Webmachine 15 15 Wednesday, 14 November 12
16. Hypermedia APIs Resources 16 16 Wednesday, 14 November 12
17. Hypermedia APIs 17 class HomeResource < Webmachine::Resource def allowed_methods %W[GET] end def expires Time.now + 2.weeks end def languages_provided [“en-us”] end end 17 Wednesday, 14 November 12
18. Hypermedia APIs 18 allow_missing_post? allowed_methods base_uri charsets_provided content_types_accepted content_types_provided create_path delete_completed? delete_resource encodings_provided expires finish_request forbidden generate_etag is_authorized? is_conflict? known_content_type? known_methods language_chosen languages_provided last_modified malformed_request? moved_permanently? moved_temporarily? multiple_choices? options post_is_create? previously_existed? process_post resource_exists? service_available? uri_too_long? valid_content_headers? valid_entity_length? validate_content_checksum variances Callbacks 18 Wednesday, 14 November 12
19. Hypermedia APIs 19 Webmachine::Application.new do |app| app.routes do add [], HomeResource end end 19 Wednesday, 14 November 12
20. Hypermedia APIs Representation 20 20 Wednesday, 14 November 12
21. Hypermedia APIs HTML 21 21 Wednesday, 14 November 12
22. Hypermedia APIs 22 <!DOCTYPE html> <html lang=”en”> <body> <a href=”...” rel=”../vehicles”>Vehicles</a> </body> </html> Example HTML Representation 22 Wednesday, 14 November 12
23. Hypermedia APIs 23 class HomeResource < Webmachine::Resource … def content_types_provided [[‘text/html’, :to_html]] end def to_html template = Slim::Template.new(“home_representer.slim”) template.render end end 23 Wednesday, 14 November 12
24. Hypermedia APIs HAL+JSON 24 24 Wednesday, 14 November 12
25. Hypermedia APIs 25 { “_links”: { “self”: { “href”: “.../api” }, “vehicles”: { “href”: “.../vehicles” } } } Example HAL+JSON Representation 25 Wednesday, 14 November 12
26. Hypermedia APIs ROAR 26 26 Wednesday, 14 November 12
27. Hypermedia APIs 27 module HomeRepresenter include Roar::Representer::JSON include Roar::Representer::JSON::HAL include Roar::Representer::Feature::Hypermedia link :self do "/api" end link :vehicles do ".../vehicles" end end 27 Wednesday, 14 November 12
28. Hypermedia APIs 28 class HomeResource < Webmachine::Resource … def content_types_provided [[‘application/hal+json’, :to_hal]] end def to_hal home = Object.new.extend(HomeRepresenter) home.to_json end end 28 Wednesday, 14 November 12
29. Hypermedia APIs Next Steps 29 29 Wednesday, 14 November 12
30. Hypermedia APIs Conclusion 30 30 Wednesday, 14 November 12
31. Hypermedia APIs Questions? 31 31 Wednesday, 14 November 12
32. Hypermedia APIs Additional Resources 32 seancribbs/webmachine-ruby apotonick/roar Jon Moore’s 2010 Oredev talk Steve Klabnik: “Designing Hypermedia APIs” Mike Amundsen: “Building Hypermedia APIs” Webber/Robinson: “REST in Practice” RESTFest 32 Wednesday, 14 November 12