REST

REST: Representational State Transfer

REST as an architectural style. In fact, it's the architectural style of the Web. REST describes what makes the Web work well. Adhering to the REST principles will make your services work well in the context of the Web.

Principles of REST Web Service Design

1. The key to creating Web Services in a REST network (i.e., the Web) is to identify all of the conceptual entities that you wish to expose as services. Above we saw some examples of resources: parts list, detailed part data, purchase order.
2. Create a URL to each resource. The resources should be nouns, not verbs. For example, do not use this:
   http://www.parts-depot.com/parts/getPart?id=00345
   Note the verb, getPart. Instead, use a noun:
   http://www.parts-depot.com/parts/00345
3. Categorize your resources according to whether clients can just receive a representation of the resource, or whether clients can modify (add to) the resource. For the former, make those resources accessible using an HTTP GET. For the later, make those resources accessible using HTTP POST, PUT, and/or DELETE.
4. All resources accessible via HTTP GET should be side-effect free. That is, the resource should just return a representation of the resource. Invoking the resource should not result in modifying the resource.
5. No man/woman is an island. Likewise, no representation should be an island. In other words, put hyperlinks within resource representations to enable clients to drill down for more information, and/or to obtain related information.
6. Design to reveal data gradually. Don't reveal everything in a single response document. Provide hyperlinks to obtain more details.
7. Specify the format of response data using a schema (DTD, W3C Schema, RelaxNG, or Schematron). For those services that require a POST or PUT to it, also provide a schema to specify the format of the response.
8. Describe how your services are to be invoked using either a WSDL document, or simply an HTML document.

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