Different representations of one resource

Question

When i have a resource, let's say customers/3 which returns the customer object and i want to return this object with different fields, or some other changes (for example let's say i need to have include in customer object also his latest purchase (for the sake of speed i dont want to do 2 different queries)).

As i see it my options are:

customers/3/with-latest-purchase
customers/3?display=with-latest-purchase

In the first option there is distinct URI for the new representation, but is this REALLY needed? Also how do i tell the client that this URI exist?

In the second option there is GET parameter telling the server what kind of representation to return. The URI parameters can be explained through OPTIONS method and it is easier to tell client where to look for the data as all the representations are all in one place.

So my question is which of these is better (more RESTful) and/or is there some better way to do this that i do not know about?

score 1 · Accepted Answer · answered Jan 14 '13 at 14:47

1

I think what is best is to define atomic, indivisible service objects, e.g. customer and customer-latest-purchase, nice, clean, simple. Then if the client wants a customer with his latest purchases, they invoke both service calls, instead of jamming it all in one with funky parameters.

Different representations of an object is OK in Java through interfaces but I think it is a bad idea for REST because it compromises its simplicity.

answered Jan 14 '13 at 14:47

amphibient

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But from what i understand it is best practice to merge more resources into one to reduce the number of requests... – Dusan Kasan Jan 14 '13 at 15:21
i wouldn't do it. it may be a small performace enhancement at the expense of code cleanliness and simplicity – amphibient Jan 14 '13 at 15:27

score 0 · Answer 2 · answered Jan 14 '13 at 16:07

There is a misconception that making query parameters look like file paths is more RESTful. The query portion of the address is included when determining a distinct URI so the second option is fine.

Is there much of a performance hit in including the latest purchase data in all customer GET requests? If not, the simplest thing would be to do that so there would neither be weird URL params or double requests. If getting the latest order is a significant hardship (which it probably shouldn't be) there is nothing wrong with adding a flag in the query string to include it.

Different representations of one resource

2 Answers2