Rails (and therefore ActiveResource) assume that for every resource (users, posts...) you have available the following endpoints (I excluded the endpoint prefix):
- GET
/users.json
to get all of the users - GET
/users/2.json
to get details about user with ID = 2 - POST
/users.json
to create a new user - DELETE
/users/2.json
to delete user with ID = 2 - PUT
/users/2.json
to update user with ID = 2
You can choose the data format like this:
User.format = :xml
User.find(2) # => GET /users/2.xml
It would probably be best if you create a new Rails app, scaffold the user resource and play with it from console. That way you could also see the data expected data structure.