Re: Mediatypes that map to application/ld+json with a profile

Hi Sarven, Phil, Rob,

> Are there mediatypes that map to application/ld+json with a profile? 

This begs the question why one would want to do that.

The problem with specific MIME types is
that they are only one-dimensional.
What if multiple dimensions have to be considered?
What if I want an activity represented in RDF,
but not in JSON-LD? Do we need things like
application/activity+turtle or +xml? That doesn't scale…

Why would we want to have such specific media types
when we already have media types for RDF syntaxes?
After all, the whole idea of RDF data is that it is self-descriptive;
that a client can understand that a document contains
an activity / person / building by interpreting it.
application/activity+json should be totally unnecessary.

Note that there is currently no official interpretation of the + token,
so a client cannot even assume application/xxx+json is a JSON(-LD) document.
Clients have to he hard-coded for application/activity+json.
This defeats much of the purpose of RDF.

>> Format/serialisation/Mime Type, whatever, is not enough. You need to 
>> know the profile. Erik Wilde has an internet draft on this [1] too.

I definitely think profiles are the way to go.

>> Should we also consider it as another dimension of content negotiation? 


Definitely. That's the only use case I see for application/activity+json-ish things,
telling a server that you expect a certain vocabulary / profile.
So I'd expect a client to say
    Accept: text/turtle;profile="http://example.org/activity"
instead.

>>> The Web Annotation WG decided /not/ to do this, and to only use a profile.  So the media type for the JSON-LD annotation serialization is:   application/ld+json;profile="http://www.w3.org/ns/anno.jsonld"

I love it; that's the most scalable way to do this,
and it does justice to what RDF stands for:
the interpretation is inside of the message.

How is it actually implemented?
It should be sufficient that the client does
    Accept: application/ld+json;profile="http://www.w3.org/ns/anno.jsonld"
and the server only says
    Content-Type: application/ld+json
since the rest would be in the message.

Actually, the client should also be able to say
    Accept: text/turtle;profile="http://www.w3.org/ns/anno.jsonld"
to which the server would reply with
    Content-Type: text/turtle
but I guess the notion of "profile" (RFC 6906)
here is to be interpreted more strictly as "JSON-LD profile".
I would be interesting to consider
    Accept: application/ld+json;profile="http://www.w3.org/ns/anno"
without any extension, allowing content negotiation on the profile.

Best,

Ruben

PS Wrote more about that here:
– http://ruben.verborgh.org/phd/ruben-verborgh-phd.pdf#page=103
– http://ruben.verborgh.org/blog/2015/10/06/turtles-all-the-way-down/

Received on Saturday, 16 July 2016 04:22:18 UTC