restifarian

A RESTifarian is a zealous proponent of the REST

REST

REpresentational State Transfer

Is an architectural style for distributed systems

Conforming to the REST constraints is generally referred to as being "RESTful"

rest

The key abstraction of information in REST is a resource. Any information that can be named can be a resource: a document or image, a temporal service (e.g. "today's weather in Ra'anana")

REST components perform actions on a resource by using a representation

Resource based

Things (resources) vs actions

Nouns vs verbs:

(GET) scheduler/channels - getSchedulerChannels();

Versus SOAP-RPC (Simple Object Access Protocol)
Identified by URIs
Multiple URIs (may) refer to the same resouce

Representations

A serialized description of a resource

Example:

Resource: channel (CNN)
Service: view meta data (GET)
Representation:
call-sign, alias, multicast feed, etc
JSON/XML format

HTTP

HTTP is a request/response protocol

request

response

http verbs

They mean something

rest constrains

Uniform Interface
Stateless
Cache
Client-Server
Layered system
Code on Demand

Uniform Interface

The uniform interface constraint defines the interface between clients and servers. It simplifies and decouples the architecture, which enables each part to evolve independently

HTTP verbs (CRUD)

URIs (resource name)

HTTP response (status, body)

Statless

Server contains no client state
Each request contains enough context to process the message (self descriptive messages)
Any session state is held on the client

Visibility
Reliability
Scalability

stateless

Visibility is improved because a monitoring system does not have to look beyond a single request datum in order to determine the full nature of the request
Reliability is improved because it eases the task of recovering from partial failures
Scalability is improved because not having to store state between requests allows the server component to quickly free resources

Cache

As on the World Wide Web, clients/CDN can cache responses.

This gives us: The advantage of having the potential to partially or completely eliminate some interactions, improving efficiency

Each request must declare it's own caching rule:

Implicitly
Explicitly
Negotiate

Client - server

Separation of concerns is the principle behind the client-server constraint.
By separating the user interface concerns from the data storage concerns, we improve the portability of the user interface across multiple platforms and improve scalability by simplifying the server components.
Components to evolve independently

layered system

A client does not need to know to whom it's connected.

By restricting knowledge of the system to a single layer, we place a bound on the overall system complexity and promote substrate independence

The primary disadvantage of layered systems is that they add

overhead and latency to the processing of data.

Code on demand

(optional)

Servers are able to temporarily extend or customize the functionality of a client by transferring logic to it that it can execute.

The reply can be javascript file, java applet

response types

Generally using the HTTP status code to describe the result

1xx: Infomration (100: continute...)

2xx: Success (200:ok, 201: created...)

3xx: Redirection (301: moved permanently)

4xx: Client error (400: bad request, 404: not found...

5xx: Server error (500: internal error, 501: not impl...)

Examples

https://developer.linkedin.com/apis

http://developers.facebook.com/docs/reference/api/

https://dev.twitter.com/docs/api

http://docs.amazonwebservices.com/AmazonS3/latest/API/APIRest.html

http://developer.nytimes.com/docs/article_search_api

https://developers.google.com/translate/v2/using_rest

.....

In the wild

Resources

http://www.ics.uci.edu/~fielding/pubs/dissertation/rest_arch_style.htm

Type 'what is RESTful service' in google...dahhhh