Re: [media-types] Rethinking Media Types

Not to take this off topic BUT since we are talking about media, I would
add when defining 'content-type' you can INFER 'accept'

Over 90% of  requests EXPECT to return the same format as is being
requested.

It is actually an aberration to request in one format and send in a
different. Breaks ASSUMED LOGIC.

Owen Rubel
orubel@gmail.com


On Thu, Jan 9, 2025 at 10:58 AM Roy T. Fielding <fielding@gbiv.com> wrote:

> On Jan 9, 2025, at 10:00 AM, Rahul Gupta <cxres@protonmail.com> wrote:
>
> Hi Michael,
>
> I am not at all suggesting that media types are not already useful. If
> anything, quite the opposite, they are necessary to REST. To quote Roy
> Fielding <
> https://roy.gbiv.com/untangled/2008/rest-apis-must-be-hypertext-driven>, "A
> REST API should spend almost all of its descriptive effort in defining the
> media type(s) used for representing resources and driving application
> state, or in defining extended relation names and/or hypertext-enabled
> mark-up for existing standard media types".
>
>
> To clarify, REST requires some form of standard typing mechanism to
> declare media types because that is how senders communicate an intended
> processing mechanism (when applicable). That's part of the style.
>
> One architecture in that style is defined by HTTP, which specifically
> defines internet media types for that purpose. But, again, that purpose is
> to express an intended processing mechanism. Not a data format, though of
> course many processing mechanisms are specific to a standard data format.
>
> This can be clearly seen in the fact that many media types are applicable
> to the same sequence of bits, just as application/octet-stream can be used
> as the type for any byte-delimited data format.
>
> Internet media types are also used by many other protocols, with other
> architectural styles, though in most cases (like email) it is generally
> true that the media type indicates an intended processing model rather than
> (just) a data format.
>
> My assertion here is that content negotiation can be more powerful with
> better evolvability characteristics, if media types could be made modular.
> It will make it easier to define formats with greater specificity, without
> a proliferation of media-types (which comes with a registration burden).
>
>
> There are three problems with that assertion:
>
>  1) Internet media types are already defined and deployed, as is;
>  2) The actual data format(s) of a media type are defined by reference,
> regardless; and,
>  3) Any focus on modularity of data format ignores the fact that the media
> type's primary purpose is to indicate an intended processing mechanism,
> which is not defined by a modularity of formats. In fact, a single media
> type could include dozens of distinct data formats, assuming they have the
> same purpose and can be internally parsed by the recipient.
>
> ....Roy
>
>