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Re: Feedback on Internet Media Types and the Web

From: Larry Masinter <masinter@adobe.com>
Date: Mon, 7 Feb 2011 18:58:27 -0800
To: "Eric J. Bowman" <eric@bisonsystems.net>
CC: "www-tag@w3.org" <www-tag@w3.org>
Message-ID: <43944624-9c16-4284-8cfe-63ff96aaa610@blur>
Eric, I have to confess that I didn't responds to this message thread in the latest draft, and perhaps it is because I still don't understand (or perhaps disagree with you about) the nature of the problem.

For "+json" to be useful for anything, it has to mean something that everyone agrees to it meaning... and the only way we have of getting that agreement is to publish a document and put it through a consensus process (notwithstanding those who prefer the" willful violation" path). If you think there is not a requirement for agreement on meaning, or another path for getting (and keeping) agreement, or that I'm wrong somehow here..... could you explain?

Connected by DROID on Verizon Wireless

-----Original message-----
From: "Eric J. Bowman" <eric@bisonsystems.net>
To: Larry Masinter <masinter@adobe.com>
Cc: "www-tag@w3.org" <www-tag@w3.org>
Sent: Sat, Jan 15, 2011 07:34:26 GMT+00:00
Subject: Re: Feedback on Internet Media Types and the Web

You're right, Larry, in that nothing prevented RFC 4627 from defining
+json from the get-go, or prevents it being changed now.  But that
won't solve the registry failure this omission revealed, which I'd like
to see prevented from recurring as a matter of course.  Codifying the
existing +xml-analogous consensus, would establish categorization of
media types by meta-language suffix the community expects from the
registry -- thereby providing Ned with the tools he's asked for to
enable the maintenance of same, by forcing the issue of changing RFC
4627 and preventing similar situations in the future.

Larry Masinter wrote:

> If they're not willing to do that work, then perhaps it isn't
> important that the +json MIME types actually be defined...

I can't chalk this up to the unwillingness of anyone to do the work
nobody ever told them needed doing.  If Ned had spent the past five
years requiring JSON-based applicants to use +json and pointing out that
RFC 4627 needed changing first, that work would've been done by now.

This advice to applicants is common both on and off the ietf-types list,
but Ned hasn't endorsed it, resulting in +json getting dropped from
applications as the path of least resistance to approval -- *that's* the
problem because it's the opposite of how the registry best serves its
architectural function (besides the fact that everyone assumes that's
how it already works).

Ned tells us he'd like to require +json, but feels his hands are tied
by RFC 4288, so it's more likely a lack of motivation rather than a
lack of willingness; I think there's a lack of awareness which results.
Regardless of cause, the effect is detrimental to the relevance of the
registry the architecture is dependent upon, and needs to be fixed in
the general case to prevent, say, YAML from making the same mistake
when it moves through the registration process, and so on into the
future.  I'm not blaming Ned, I'm advocating we not leave him any more
such messes to clean up after.

Each approval of a JSON type sans +json, represents one less group
willing to do the work of changing RFC 4627, and one more registry entry
that can't be searched for by generic parsing model.  Or one less
registry entry, and one more +json not-a-media-type released into the
wild, where nobody can search for it unless its token is known.  The
+json issue is only an example of the registry failure which results
from leaving suffixes undefined -- changing RFC 4627 doesn't fix the
underlying problem.

Ideally when dealing with registries in general, it's required to
identify this sort of pattern such that over time, fewer entries are
required to be updated to obsolete old tokens in favor of new tokens.
This has happened with several prominent media types, with problematic
results.  So we should be proactive in keeping this from happening to
every proposed media type based on a non-XML meta-language, by fixing
the general registry failure +json illustrates before it's compounded.

Especially because it's a problem for which a consensus solution
already exists, which, if solved now, will avoid the suffix travelling
down the path to irrelevancy text/* has in practice...

> The problem is that using something like "+json" without having
> a definition for what it means doesn't really help anyone except
> if you think that a MIME type is a fashion accessory and not a
> protocol element with a definite meaning.

Exactly the point I've been making, to so much consternation, on rest-
discuss for a year and a half now.  One rebuttal was, "Where in AWWW
does it say that?"  So I see this issue as a relevant example of the
sort of thing a revised AWWW could clarify (especially since I pointed
to your draft as proof that media type omission was a known AWWW bug).
Hopefully, AWWW is updated to clarify the new standardization of
suffix usage, where it discusses proper media type creation and use,
which is why I think the issue belongs here -- these are orthogonal

> There's nobody home but us. So there's no one else other than the
> JSON-mime-type using community to define what "+json" means.

It's no more the place of the JSON folks to codify that MIME suffixes
mean what everyone now thinks they mean, than it is for the XML folks.
Such an effort would be open to charges of changing RFC 4288 to reflect
the needs of +json or +xml rather than the needs of +anything.  As Ned
points out, others have a different opinion, like +vendor -- those
folks need to have their say about generic suffix syntax, in a forum
outside those of +xml-ish suffix instantiations.

I believe it would make all the difference in the world if the JSON-
media-type-using community were told they need to define +json, instead
of being told they need to drop +json (like they are now) and try again.
Fix the process, and the definition of +json will duly follow.  Or in
this case, create the process.

> ...and perhaps they're just "mime-type-like" labels because there's
> nothing in particular you would or should do if you get a text/frob
> +json MIME body. Right? At least with XML there was some expectation
> of generic processing either with CSS or with XSLT.

I'm not a JSON user (yet, perhaps), but I believe there is a generic
processing model as with XML.  I may not know the context or semantics
of a JSON document (same with XML), but I can still tell by looking at
it what's a real vs. integer number, vs. a string, boolean, array or
object.  As with XML, the document may be seen as a collection of
name-value pairs; typing is inherent and nonextensible in JSON, while
in XML it is an extensible option.  JSON is a subset of YAML, which
allows more complex typing in its generic processing model.

I think JSON and YAML are exactly the sort of languages the suffix
registry should target, as they may be extended to have semantic
meaning expressed as a data-type family identified by a media type in
exactly the same way as XML is extended to have HTML semantics using
application/xhtml+xml.  The syntax parsing is
Received on Tuesday, 8 February 2011 02:58:45 UTC

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