On Thu, 4 Nov 2010 13:22:09 +0000 Ian Davis <[email protected]> wrote:
> http://iand.posterous.com/is-303-really-necessary Ian brings up numerous difficulties with 303 responses. The two biggest issues in my opinion are: 1. 303s can be tricky to configure unless you know your way around the server environment you're using, and have sufficient permissions on the server; and 2. They require an additional HTTP request to get to the data the client actually wants. I think that without using RDF-specific publishing platforms (think WordPress for Linked Data) #1 is always going to be a difficulty. Even if we accept 200 OK as a response code for non-IR resources, this only solves part of the server configuration problem. There are still other issues to be solved - Apache doesn't come preconfigured with media type information for N3/Turtle/N-Triples. And getting neat-looking URIs (no ".rdf" suffix at the end) requires something like mod_rewrite, Apache multiviews or ForceType to be configured. You could try publishing an N-Triples file with no suffix, and cross your fingers that Apache's default media type of "text/plain" will bubble up. #2 on the other hand can be addressed quite easily. 303 responses are allowed -- indeed encouraged -- to include an entity body. Servers could be configured to duplicate the description of the non-IR resource in this entity body. Or perhaps provide a more summarised description there. Clients just need to look at it before deciding whether to follow the redirect. e.g. >>>> GET /toucan HTTP/1.1 Host: example.com <<<< HTTP/1.1 303 See Other Location: http://example.com/doc Content-Type: text/turtle @prefix foaf: <http://xmlns.com/foaf/0.1/> . <toucan> foaf:name "Harry the Toucan" ; foaf:isPrimaryTopicOf <doc> . !!!! Here the client decides whether that's enough information. !!!! If it needs more, it continues by dereferencing <doc>. >>>> GET /doc HTTP/1.1 Host: example.com <<<< HTTP/1.1 200 OK Content-Location: http://example.com/doc.ttl Content-Type: text/turtle @prefix foaf: <http://xmlns.com/foaf/0.1/> . <toucan> foaf:name "Harry the Toucan" ; foaf:isPrimaryTopicOf <doc> ; foaf:birthday "10-24" . <doc> foaf:maker <alice> . -- Toby A Inkster <mailto:[email protected]> <http://tobyinkster.co.uk>
