I’m designing a RESTful service aligning to HATEOAS principles as much as possible. As a result, I need a way to have my cool URLs return a list of links describing available options. I’m using HAL-JSON to facilitate the data format so that’s all good, but I’m now considering what HTTP method should pull this.
I’m sure I could stick with a simple GET, but from reading over the HTTP RFC, it seems that OPTIONS might fit the bill here. My only concern is in bold:
9.2 OPTIONS
The OPTIONS method represents a request for information about the
communication options available on the request/response chain
identified by the Request-URI. This method allows the client to
determine the options and/or requirements associated with a resource,
or the capabilities of a server, without implying a resource action or
initiating a resource retrieval.Responses to this method are not cacheable.
Could someone with more experience on the standards side of the web please explain why this is the case? In my view, you would certainly want clients caching this result at least for a short period of time, as in a fully HATEOAS system this call is likely to be made quite frequently to traverse the rel links to arrive at the operation you’re looking for.
I’d also love some opinions on using OPTIONS vs a simple GET for retrieval of operations from a cool URL.
It’s not cacheable, period. Sorry.