title: Web Services REST-Style: Universal Identifiers, Formats & Protocols


h1. Web Services REST-Style: Universal Identifiers, Formats & Protocols

Agenda

* What's REST?
* Universal Identifiers, Formats & Protocols 
* The Holy REST Trinity - Noun, Verbs, Types
* REST Design Principles 
* Architecture Astronaut REST Speak


h1. What's REST?

Representational State Transfer (REST) - Meaningless Acronym? Wordplay?

rest - n. - peace, ease, or refreshment resulting from the insight that the web works

No matter what vendors tell you - no need to "Light Up the Web" - relax - built on an *open architecture using universal identifiers, formats & protocols and _evolving_ open standards* - no need to reinvent the wheel and sign-up for single-vendor offerings.

h3. Broad Definition

* Best Practices for Designing Web Services for a Unified Human and Programable Web

h3. Narrow Definition

* Alternative to BigCo Web Services (SOAP, WS-STAR) and RPC-Style Web Services (XML-RPC)

h3. Resource, Representation, State, Transfer

* (Stateless) Resource Representation -> Open Format + Identifier e.g. HTML+URI
* Transfer Rules (Protocol) e.g. HTTP


h1. Universal Identifiers, Formats & Protocols - The Holy Trinity

* Identifiers -> URLs (Uniform Resource Locator), URIs (Uniform Resource Identifier)
* Formats -> HTML (HyperText Markup Language), XML (Extensible Markup Language)
* Protocols -> HTTP (HyperText Transfer Protocol), AtomPub (Atom Publishing Protocol)


h1. The Holy REST Trinity - Noun, Verbs, Types

REST-Speak -  Internet-Speak  - Plain Old English

* Verbs  -> Protocols    -> Communication & Data Exchange Rules
* Nouns  -> Identifiers  -> Names, Addresses
* Types  -> Formats      -> Documents, Feeds, Photos, Videos, Music, etc.

* Verbs -> HTTP GET, POST, PUT, DELETE
* Nouns -> @flickr.com/photos/tag/vancouver@, @deli.cio.us/vanajax/tag/libraries@, etcetera
* Types -> HTML, RSS, PNG, etcetera


h1. REST Design Principles - What's REST?

* Idenifiers Matter - Choose Great Names
* Open Formats Matter - Avoid Vendor Lock-In
* Protocols Matter - Learn more about HTTP and Use Best Practices
**  Use HTTP GET for Read-Only/Side-Effect-Free Requests
**  Use HTTP Accept Headers for Format Selection
**  Use Full HTTP Method Vocabulary (GET, POST, PUT, DELETE)

* No Web without Linking and No Linking without Identifiers!
* (Stateless) Resource Representation -> Open Format + Identifier e.g. HTML+URI


h1. Architecture Astronaut REST Speak

* REST-y
* REST-ful

* Resource-Oriented Architecure (ROA)
* Web-Oriented Architecure (WOA)

* REST-RPC-Hybrid (Three Web Service Architectures - 1) REST, 2) REST-RPC Hybrid, 3) RPC[1] )

fn1. RPC -> Remote Procedure Call