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Re: Media types

From: Paul Prescod <paul@prescod.net>
Date: Tue, 15 Jan 2002 15:00:13 -0800
Message-ID: <3C44B47D.DE3DE1FC@prescod.net>
To: Gavin Thomas Nicol <gtn@rbii.com>, www-tag@w3.org
Gavin Thomas Nicol wrote:
> 
>...
> 
> In this statement you are logically testing each and every definition
> of type against the document to determine. My whole point is that you
> shouldn't need to look at the document to determine the processor...
> the document should already have been routed to it by some external
> means.

We're talking on two different levels. One is the level of platonic
ideals. What specifications does this pile of bits conform to and what
was the author's intent. A second is making stuff work with software. If
we don't know what the right thing is then we can't figure out how to
make software do it.

>...
> This is in the right general direction. My  opinion is that
> "type" is purely in the mind of the interpreter... so the question of
> establishing  "type" is irrelevant... we need to determine the
> appropriate processor. 

The receiver chooses the processor. Server-declared type is an input
into the decision making process.

> ... In HTTP (and in MIME in general), the MIME type
> is used to determine the *processing* (typically a viewing/playback
> processor, but not necessarily)... so this is one means toward that
> end.

And another would be....what?

>...
> My point here is that there are an infinite number of ways a given
> document could be processed... so sniffing at elements isn't going to
> help you much with the decision.

The receiver knows what it is trying to do: view, edit, index, etc. The
receiver knows the set of software components available to it. The
sender knows more about the actual data than the receiver does. So it
should supply metadata that will help the receiver to make its decision.

The server-declared type is one important piece of metadata that the
client can use to determine what component it should use. It is probably
not the only thing it uses but it is an important part of the decision
making process. So it is not irrelevant by any stretch.

>...
> For the moment, MIME type, or whatever other mechanism the transport
> layer provides should be used to infer the processing to be performed.
> In the long run, we need something else....

Like....

 Paul Prescod
Received on Tuesday, 15 January 2002 18:04:27 GMT

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