Should resource ids be present in urls?

Question

In situations where the resource id can be identified by other means (such as current_user for pages that require authentication), is it a good idea to omit the id from the url? (For example, /students/1/homework to /students/homework).

Also, would this have any impact on the restfulness of the urls? I am suspecting it does for HTTP verbs, but for custom actions I am not so sure.

Answer 1

URLs should always point to one specific resource. They can either be absolute or relative. Think of it as a filesystem. In some cases (security/scalability) you can't allow listings.

• Session-based / Relative resources /students/me, /students/latest, /students/latest/homework/lastest
• Absolute resources /students/3, /students/3/homework, /teachers/3/homework/3

Answer 2

I suppose it is down to your application and what is useful for clients to see. If your connecting user is an admin who can see all students homework, then the /students/1/homework path makes sense, however if it will only ever be students using this resource then the /students/homework makes more sense.
Essentially the latter could be thought of as a namespace for all student resources.
I have found it very useful to split these resources by namespaces as to not confuse client writers and keep your authorisation very clear (who can see/do what).

Answer 3

In your example, the 2 URIs identify different resources:

• the homework of user #1,
• the homework of the current user.

The choice depends a lot on which resource you think people will want to refer to (by e-mail or by bookmark for example).

I don't think the second solution is unRESTful, but I would prefer the first one, since it is compatible with a lot of additional features (e.g. teachers could access the representation of students' homework).