rest/urls

URL Conventions

These are the recommended conventions for RESTful URLs, based on work pioneered by Ruby on Rails . Following these conventions for both HTTP method names and URL construction will allow your application to be consumed by ActiveResource, Jester, and other RESTful clients. Note that Rails 1.x used ";edit" and ";new" in place of the simpler "/edit" and "/new" recommended going forward.

Methods

One of the key aspects of REST is using the HTTP Verbs to implement the standard Create-Retrieve-Update-Delete (CRUD) database semantics. The primary ones are:

POST

Create a resource within a given collection

GET

Retrieve a resource

PUT

Update a resource

DELETE

Delete a resource

Note that most browsers do not currently support PUT and DELETE, so those need to be implemented using a POST with an "?_method=" argument.

Routing

The principal unit of operation is the "collection", which typically corresponds to a database table or (in Rails) an ActiveRecord class. For a collection named "people", the primary routes would be:

Operate on the Collection

GET /people

return a list of all records

GET /people/new

return a form for creating a new record

POST /people

submit fields for creating a new record

Operate on a Record

GET /people/1

return the first record

DELETE /people/1

destroy the first record

POST /people/1?_method=DELETE

alias for DELETE, to compensate for browser limitations

GET /people/1/edit

return a form to edit the first record

PUT /people/1

submit fields for updating the first record

POST /people/1?_method=PUT

alias for PUT, to compensate for browser limitations

Follow a Relationship

GET /people/1/phones

return the collection of phone numbers associated with the first person

GET /people/1/phones/23

return the phone number with id #15 associated with the first person

GET /people/1/phones/new

return a form for creating a new phone number for the first person

POST /people/1/phones/

submit fields for creating a new phone number for the first person

Invoke Custom Actions

It isn't always possible to map everything into CRUD. Thus, there is also a syntax for specifying custom actions:

POST /people/1/promote

run the "promote" action against the first record

These should be used sparingly, as they are unlikely to be supported by most clients.

File Formats

Data types are extremely important in REST. While it is ideal to specify the appropriate MIME type as an HTTP header, developers are encouraged to follow Rails in allowing extension-based typing, e.g.:

HTML

GET /people/1

return the first record in HTML format

GET /people/1.html

return the first record in HTML format

XML

GET /people/1.xml

return the first record in XML format

JSON

GET /people/1.json

return the first record in JSON format

While the JSON mapping should be trivially obvious, the best practice for XML is to:

1. use the column name as the element name
2. include an appropriate "type" field

See the Highrise reference for an example of how this works in practice.

Response Codes

Another important aspect of REST is returning the appropriate HTTP Response Codes.

Examples in the Wild

• Ruby on Rails
• Highrise
• Java
• Python
• Jester (JavaScript)
• ....