Representational State Transfer (REST)
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REST (REpresentational State Transfer) is an architectural style for building web APIs that relies on HTTP verbs like GET, POST, PUT, and DELETE to manipulate resources identified by URIs. Resources can have multiple representations like JSON or XML, and the appropriate representation is selected via content negotiation. REST aims to provide a simple, lightweight interface and takes advantage of existing web protocols to transfer representations of resources between clients and servers. Key REST constraints include using nouns for resources and HTTP methods for actions, making the interface lightweight, client-server, cacheable, and layered.
![http://app.com/pics/1
What remains:
a (unique) resource identifier
an “abstract thing” that lives in the cloud
a.k.a. ”the intended conceptual target of a
hypertext reference” :]
a representation of the resource
(you can never access the resource itself, only various representations of it)](https://image.slidesharecdn.com/rest-davidkrmpotic-150205192849-conversion-gate01/85/Representational-State-Transfer-REST-5-320.jpg)
![A resource is not always a one-to-one
mapping to a Rails model or database table.
Sometimes a resource is "virtual" and exists in
your domain vocabulary and application logic,
but is not backed by a database table. [2]
GOOD TO KNOW
models != resources](https://image.slidesharecdn.com/rest-davidkrmpotic-150205192849-conversion-gate01/85/Representational-State-Transfer-REST-21-320.jpg)
![Thank you!
Resources (n.p.i.)
[1] Roy Fielding’s dissertation (2000)
www.ics.uci.edu/~fielding/pubs/dissertation/top.htm
[2] REST 101
www.softiesonrails.com/search?q=rest+101
[3] A Brief Introduction to REST
www.infoq.com/articles/rest-introduction
[4] How I Explained REST to My Wife
tomayko.com/writings/rest-to-my-wife](https://image.slidesharecdn.com/rest-davidkrmpotic-150205192849-conversion-gate01/85/Representational-State-Transfer-REST-23-320.jpg)
Representational State Transfer (REST)
- 1. REST representational state transfer David Krmpotić
- 2. WHAT IS IT?
- 3. Architectural style that builds on the existing protocols of the web. Roy Fielding
- 4. http://app.com/pics/show/1 http://app.com/pics/destroy/1 RESTful style knocks the verbs out of the urls
- 5. http://app.com/pics/1 What remains: a (unique) resource identifier an “abstract thing” that lives in the cloud a.k.a. ”the intended conceptual target of a hypertext reference” :] a representation of the resource (you can never access the resource itself, only various representations of it)
- 6. http:// GET app.com/pics/1 We have nouns (resources), but what happened to the verbs? http:// DELETE app.com/pics/1 they moved from the URL to the HTTP request method !
- 7. IS THIS A GOOD THING?
- 8. simplicity and abstraction GET PUT POST DELETE Yes! } uniform interface
- 9. REST is about resources Nouns URIs (unconstrained) Verbs GET, PUT, POST, DELETE (constrained) Content Types HTML, JPEG, XML etc. (constrained)
- 10. GET /pics/1 Accept: JPEG or GET /pics/1.jpg Requesting different resource representations GET /pics/1 Accept: XML or GET /pics/1.xml <picture> <place>Axe Lake</place> <size>1024x768</size> <date>2008-05-01</date> </picture>
- 11. GET /people Accept: XML Plural resources GET /people/1 Accept: JPEG <people> <person> <id>1</id> <name>Ann</name> <age>28</age> </person> <person> <id>2</id> <name>Bruce</name> <age>32</age> </person> ... </people>
- 12. It relies on the following standards though: HTTP URL XML/HTML/GIF/JPEG/etc (resource representations) text/xml, text/html, image/gif, image/jpeg, etc. (content types) remember REST is not a standard!
- 13. REST in
- 14. Before enlightenment http://app.com/clients/show/1 After controller action http://app.com/clients/1 + HTTP method controllermap.resources action
- 15. map.resources action where the request lands is shown with gray background edit and new are helper actions for showing the form
- 17. We also get a few named routes: clients_path new_client_path edit_client_path(id) client_path(id)
- 18. Custom actions GET /tasks/completed PUT /tasks/12/complete you should add custom actions carefully and never more than two or three
- 19. Responder block takes care of different resource representations
- 20. Nested resources (in Rails 2) http://adam.blog.heroku.com/past/2007/12/20/nested_resources_in_rails_2/ /events/1/tickets
- 21. A resource is not always a one-to-one mapping to a Rails model or database table. Sometimes a resource is "virtual" and exists in your domain vocabulary and application logic, but is not backed by a database table. [2] GOOD TO KNOW models != resources
- 22. To create a website that is: • easy to use • easy to maintain • easy to cache • easy to scale Why use REST?
- 23. Thank you! Resources (n.p.i.) [1] Roy Fielding’s dissertation (2000) www.ics.uci.edu/~fielding/pubs/dissertation/top.htm [2] REST 101 www.softiesonrails.com/search?q=rest+101 [3] A Brief Introduction to REST www.infoq.com/articles/rest-introduction [4] How I Explained REST to My Wife tomayko.com/writings/rest-to-my-wife