How to return random items RESTfully?

Question

My design exposes two kinds of resources:

1. Images
2. Tags

I would like clients to be able to request random images by their tag(s). For example

Answer 1

Multi-dimensional resource identification is challenging.

Your resource is an image, so that's your URI. Further, a specific image has a specific URI which never changes.

Your "by tag" is a non-identifying attribute of the resource. For this, a query string can belp.

Here's my first thought.

• http://www.example.com/MyStuff/image/id/ -- specific image by id
• http://www.example.com/MyStuff/image/?tag=tagname -- random image with a given tag, implicitly, count=1.
• http://www.example.com/MyStuff/image/?tag=tagname&count=all -- all images with a given tag in a random order (count=1 is the default, which would give you an arbitrary image)