REST API Get single latest resource

Question

I'm designing a REST api and interested if anyone can help with best practice in the following scenario.

I have...

• GET Customers/{customerId}/Orders - to get all customer orders
• GET Customers/{customerId}/Orders/{orderId} - to get a particular order

I need to provide the ability to get a customers most recent order. What is best practice in this scenario? Simply get all and sort by date or provide a specific method?

Answer 1

I think there is no need for another route.

Pass something like &order=-created_at&limit=1 in your get request

Or &order=created_at&orderby=DESC&limit=1 (note I'm not sure about naming your params so maybe you could use &count=1 instead of &limit=1, ditto order params)

I think it also depends whether you are using pagination or not on that route, so perhaps additional params are required

Customers/{customerId}/Orders?order=-created_at&limit=1

Answer 2

I need to provide the ability to get a customers most recent order.

Of course you could provide query parameters to filter, sort and slice the orders collection, but why not making it simpler and give the latest order if the client needs it?

You could use something like (returning a representation of a single order):

GET /customers/{customerId}/orders/latest

The above URL will map an order that will change over the time and it's perfectly fine.

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Say there is also a case where you need last 5 orders. How would your route(s) look like?

The above approach focus on the ability to get a customers most recent order requirement. If returning the last 5 orders requirement eventually comes up after some time, I would probably introduce another mapping such as /recent that returns a representation of a collection with the recent orders and accepts a query parameter that indicates the amount of orders to be returned (5 would be the default value if the parameter is omitted).

The /latest mapping would still be valid and would return a representation of the very latest order only.

Providing query parameters to filter, sort and slice the orders collection is still a valid approach.

The key is: If you know the client who will consume the API, target it to their needs. Otherwise, make it more generic. And when modifying the API, be careful with breaking changes and versioning the API is also welcome.