CODEWITHSUNDEEP
rest
lreeder
lreeder

Reputation: 12206

Why not use PUT for REST queries that require a payload?

REST recommends that queries (not resource creation) be done through the GET method. In some cases, the query data is too large or structured in a way that makes it difficult to put in a URL, and to address this, a RESTful API is modified to support queries with bodies.

It seems that the convention for RESTful queries that require bodies is to use POST. Here are a few examples:

Queries don't modify the internal state of the system, but POST doesn't support idempotent operations. However, PUT is idempotent. Why don't RESTful APIs use PUT with a body instead of POST for queries that require a body?

NOTE: A popular question asks which (PUT vs POST) is preferred for creating a resource. This question asks why PUT is not used for queries that require bodies.

Upvotes: 6

Views: 3359

Answers (2)

inf3rno
inf3rno

Reputation: 26139

You should read the standard: http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html

The definition of POST:

The POST method is used to request that the origin server accept the entity enclosed in the request as a new subordinate of the resource identified by the Request-URI in the Request-Line.

The action performed by the POST method might not result in a resource that can be identified by a URI. In this case, either 200 (OK) or 204 (No Content) is the appropriate response status, depending on whether or not the response includes an entity that describes the result.

The definition of PUT

The PUT method requests that the enclosed entity be stored under the supplied Request-URI. If the Request-URI refers to an already existing resource, the enclosed entity SHOULD be considered as a modified version of the one residing on the origin server. If the Request-URI does not point to an existing resource, and that URI is capable of being defined as a new resource by the requesting user agent, the origin server can create the resource with that URI.

If the resource could not be created or modified with the Request-URI, an appropriate error response SHOULD be given that reflects the nature of the problem.

Another thing that PUT is not cacheable while POST is.

Responses to this method are not cacheable, unless the response includes appropriate Cache-Control or Expires header fields.

e.g. http://www.ebaytechblog.com/2012/08/20/caching-http-post-requests-and-responses/

Upvotes: -2

Evert
Evert

Reputation: 99543

No. PUT might be idempotent, but it also has a specific meaning. The body of the request in PUT should be used to replace the resource in the URI.

With POST no such assumptions are being made. And note that using a POST request means that the request might not be idempotent, in specific cases it still might be.

However, you could do it with PUT, but it requires you to jump through an extra hoop. Basically, you could create a "query resource" with PUT, and then use GET immediately after to fetch the results of this query resource. Perhaps this was what you were after, but this is the most RESTful, because the resulting query results can still be linked to. (something which is completely missing if you use POST requests).

Upvotes: 4

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