Re: Format Negociation in Practice [Was: Versioning HTML at the server]

Christian L. Mogensen (mogens@CS.Stanford.EDU)
Wed, 19 Oct 1994 01:42:37 +0100

> First we need some way for clients to say what they support - accept
> text/html is too broad a brush - and have this published so everyone
> does it the same way.

I thought MIME already supported a versioning parameter?
Can't we use that:
Content-type: text/html; version=2.0

In accept:
Accept: text/html; version=2.0, image/gif; version=89

Servers can then ignore or deal with the clients request as
they feel like - maaaaybe you get a conversion, maaaaybe not.

The browsers send a list of all tags that they support
and then have the servers strip out or convert stuff the client
can't deal with. (Or you will end up with long long lsts
of what each client can and cannot support).
Ask Brian at Wired about his happy maintenance of browser capability
lists... It's no fun for the administrators.

On the other hand, why not have the server send along a list of
what the tags mean and suggestions on how to render them?
You know: like a DTD and stylesheet?

[ ;-) for the sarcasm impaired. ]

Of course, this means there has to be a mapping from the
DTD to a set of browser features: <BR> means new line.
So does <P> - what about tables? Can one specify a mapping
from the table DTD to some set of browser rendering hints?

> invoke the conversion the first time the document is requested and
> squirrel away the munged file transparently.

You're presupposing disk space here, but IMHO the best answer is
to just let the browsers deal with the problems of not understanding
some HTML tags.

If people are going to look at technical documentation, they will
tend to have technically enabled browsers with Maths and Forms.
If their browser doesn't support it, their clamouring voices
will be another encouragement for browser implementors to get
it right.

> > "Click _here_ if your browser doesn't support tables."
> > > > "Click _here_ if your browser doesn't support math."
> > "Click _here_ if your browser doesn't support stylesheets."

Banish it to the <BLINK>ing pits of hell.</BLINK>

Christian "W3O! WHERE ARE YOU?"