how should I handle subresources in REST?

Question

I understood (I think...) the basics of REST but while trying to design my API I got a little confused with sub-resources, I'll try to explain with an example:

lets say I have an application that has two resources, users and rooms, a user can create rooms and join rooms, is the following REST URIs correct ?

1. GET /users/< userID >/joinedRooms
2. GET /users/< userID >/createdRooms

or should it be something like /users/< userId >/rooms/joined or /users/< userId >/rooms?query=joined ?

also how would "get similar rooms" URI would look like ? /rooms/< roomId >/similar or /rooms/?query=similar ?

Answer 1

URL design is an art form, not a REST constraint. REST says nothing about what your URLs should look like. URLs are opaque strings and their contents is irrelevant.

• /users/<userID>/joinedRooms
• /users/<userID>/rooms/joined
• /users/<userID>/rooms?query=joined

Any of these options you have suggested are equally valid. Pick whichever one works best for you, as long as it represents a resource.

also how would "get similar rooms" URI would look like

Again, whatever you want. How about /yaz1-oPhce6~X_? :-)

When making your decision, I suggest you try to factor in things like ease of implementation, aesthetics, and so on.