Best way to submit many (equally named) parameters in GET/REST

Question

Hi

For a REST interface:

What is the best way to allow the client to set many equally named parameters in a GET?

For example if the client should specify multiple possible colors

www.example.com/products/{color=green|color=yellow|color=white| ...}

Answer 1

Something like this would be fine:

GET http://www.example.com/products?colors=green,yellow,white

Despite popular opinion, there is no REST constraint that says you should not use query string parameters.

Answer 2

if all you need is a simple query by a single parameter then I'd go with Darrel's suggestion, if your query can become more complex, you can consider SQL like query params:

GET http://www.example.com/products?query={colors IN (green,yellow,white) AND size='small')}

Answer 3

Considering browsers consider the application/x-form-urlencoded and the querystring equivalent, and considering several values can be provided for the same name, you can simply do color=red&color=green&color&blue.

Provided your framework of choice handles this correctly, this should be jsut fine.

Answer 4

For some queries, we could encounter URI length limitations. I'm curious how people have dealt with that in a RESTful fashion.

I was considering POST/PUTing a Query object with a document containing a large batch of query data, and getting the ID of that resource, then doing a GET operation, passing the query's ID.

Seems a bit less than optimal, though. Two queries, just to be RESTful.