CODEWITHSUNDEEP
rest
Sam
Sam

Reputation: 164

REST convention for a move operation

Is there a REST convention for a call to move a resource? I want to move an item (say item1) from location loc1 to location loc2. I could do a delete/insert, but that would require two separate calls. How can I do it with just one call? I've thought about several possibilities, like:

http://someapi.com/location/loc1/items/item1/location/loc2/move-item

but that looks awkward to me. In that URI it looks like the second location is a property of the item. Switching loc2 and item would then make it look as if loc2 is a property of loc1, again an awkward thing. As you can see I'm thoroughly confused, any suggestions?

Upvotes: 0

Views: 72

Answers (1)

VoiceOfUnreason
VoiceOfUnreason

Reputation: 57289

As you can see I'm thoroughly confused, any suggestions?

In REST, identifiers are identifiers. They don't have any domain semantics associated with them. You can use any spelling you want for a resource.

Your resources are usually going to be affordances - documents about things, or documents that enable protocols that do things. Think web pages with links and forms.

POST /4e52bfd1-87d0-4cf1-8b45-175fb13294f3

POST is the right method token to use for request messages that aren't worth standardizing.

The target URI will normally identify some resource that we expect to be changed by the request. The reason for this choice is that it gives us invalidation of client/intermediate caches "for free".

Most of the semantic information you need to describe this "not worth standardizing" method belongs in the payload, not in the URI.

POST /4e52bfd1-87d0-4cf1-8b45-175fb13294f3
Content-Type: text/plain

Please move /4e52bfd1-87d0-4cf1-8b45-175fb13294f3 to /fc32bf42-b757-4ae2-b164-2cb61e3ca8fd

It is normal that a single resource might accept several different kinds of requests that all use the POST method. The server can discriminate based on the payload (consider, for example, multiple web forms that all POST to the same resource - it works just fine, but you do need to include enough information in the form that the server can figure out what the request means.)

For "move" semantics specifically -- the WebDAV specification does define a MOVE method token. If those standardized semantics match what you want to do, then it could be appropriate to support that. (I tend to avoid WebDAV myself - I'm suspicious of the constraints on "WebDAV-compliant resources", and therefore somewhat concerned about what assumptions general purpose clients are entitled to make about resources when one of the WebDAV method tokens is used. It might be fine? it might not be fine? but what I'm looking for is "obviously better than using POST" and I don't see that.)

I have to admit I'm still confused about this REST thing,

That's not your fault: LOTS of people are confused by this REST thing. There is much more misleading noise than there is signal.

Three talks that might help:

Upvotes: 1

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