August 22, 2010

PUT and Content-Location

I noticed some days ago that I totally missed the use of the Content-Location header in responses to PUT requests. Used in this scenario, the client does not need an additional GET to obtain a representation of the resource after the PUT.

And what is even more interesting is that caches can also cache the response of the PUT.

PUT /orders/42
Content-Type: application/order
[...]

200 Ok
Content-Location: /orders/42
Content-Type: application/order
ETag: "1"
[...]

The Content-Location header is telling the client and intermediary: “This is the entity and entity headers you would receive for a GET to /orders/42”.