Content-Document-Type: was (Re: MIME types vs. DOCTYPE)

[Jonathan Borden]

Daniel Austin wrote:

>
> 	At this point in time, no method other than MIME types exists for
> informing the client of the type of content
> arriving, without first downloading the entire file and then
> checking it, an
> obvious absurdity. Doctypes, FPIs,
> etc. have all be suggested, but none of these solutions provides the
> necessary level of transaction control required to identify the content
> prior to content reception. Given the massive costs involved, the client
> must always be allowed to reject content prior to downloading the entire
> file.

	Please explain what:

Content-type: text/xhtml

	can possibly do for you that:

Content-type: text/xml; doctype="http://www.w3.org/xhtml.dtd"

	cannot do. (Note: the use of doctype = dtd is an example, the doctype can
point to any URI. Just like the XML namespace URI, the doctype URI serves as
a unique identifier and implies no particular meaning.

>
>
>
> > Adding an XML-specific HTTP header line makes HTTP 1.1 more complex
> > (shudder), and imposes an extra coding and testing burden on HTTP
> > implementations. Also, it does nothing for XHTML over other
> > transports,
> > like SMTP or FTP.
>
>
> 	It is also introducing a new set of dependencies for all XML
> documents. Not feasible.

	Huh!? Both these statements are patently false. As per the RFC 822 and
following specs, inclusion of a new header does not in any way alter the
syntax of HTTP or SMTP. It is specifically allowed. Both SMTP and HTTP can
deal with headers, FTP of course could care less about text/xhtml or any
other MIME header so this is moot.

	The point is to create a generalizable mechanism for content negotiation
depending on an XML namespace or DTD or Schema. XHTML like HTML 1.0 - HTML
4.0 is a soon to be historical oddity. I have nothing against HTML, just why
create a hack to solve a particular problem for XHTML version 1.0 e.g.
text/xhtml, when a generalizable solution can be created for any XML
document type e.g. text/xml; doctype=".../XHTML10.dtd". This gives the best
of both worlds.

Jonathan Borden
http://jabr.ne.mediaone.net


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