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Re: [p3-payload] Media-Type -- Two Values, One Cup Anti-Pattern?

From: Eric J. Bowman <eric@bisonsystems.net>
Date: Thu, 19 Jan 2012 21:42:22 -0700
To: "Markus Lanthaler" <markus.lanthaler@gmx.net>
Cc: <ietf-http-wg@w3.org>
Message-Id: <20120119214222.3053cdc5.eric@bisonsystems.net>
"Markus Lanthaler" wrote:
> 
> May I just ask a quick question on this. We are currently working on a
> JSON-based media type (JSON-LD) and plan to use the application/ld
> +json media type for it. Do you think that's a bad practice?
> 

I have no idea the status of that media type as a proposed standard.
If it is, then I still don't know if it's bad practice as I have no
idea what your system even does.

>
> Unfortunately in JSON there's no way to specify such processing
> instructions within the representation as you propose.
>

There's more than one way to use JSON in a system, if you need to do
something out-of-scope to JSON, you should consider a different media
type.

>
> From looking at the current registered media types and discussions
> with a number of people (mostly from the WHATWG) we thought that's
> the best practice, so I'm a bit confused now.
> 

>From looking at the string "application/ld+json", even though I don't
know what "ld" means, I know that the sender's intended processing
model is JSON-based, so I can parse it in javascript and get objects,
fwiw.

>
> A related issue we stumbled into is how we define further "subtypes".
> E.g. we will need a way to describe a "JSON-LD frame". The first idea
> was to use application/frame-ld+json
>

If you aren't going to standardize /frame-ld+json, then the appropriate
syntax and registration procedure is for the vnd. tree, i.e.
application/vnd.frame-ld+json.

>
> but some people argued that the best practice would be to use
> application/frame+ld+json which looks weird to me.
> 

The guidelines are being rewritten to include "+json" etc. right now, I
doubt multiple "+" syntax will be allowed.  What you have there isn't
what suffixes are meant to do, at all.

>
> So, in these concrete examples, what would you (and others) propose
> to use?
> 

I don't see any concrete examples to base any sort of proposal on, nor
is this the proper list for that, stick with rest-discuss.

>
> P.S.: I fear I will get a response that says: it's an opaque
> identifier and it doesn't matter
> 

I should hope not.  URIs are opaque, media types map to processing
models; the sender's intended processing model for the payload had
better not be opaque or the Web wouldn't work.

-Eric
Received on Friday, 20 January 2012 04:42:48 GMT

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