OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help



   Re: [xml-dev] Revised Internet-Draft: Media Feature - xmlns

[ Lists Home | Date Index | Thread Index ]

On Thu, 2002-01-24 at 21:22, Rick Jelliffe wrote:
> Looks good. It still falls down for the same reason that the whole
> "out-of-band signalling using MIME headers" falls down:
> there needs to be some convention (other than by parsing
> the whole document including subentities) for a webserver to 
> construct the information in the first place. 

Yep.  I agree this is difficult, and don't expect it to become easier
quickly.  See below for more.

> Is there value in constructing pipes when there are no
> feasible connectors?   At the moment, the WWW basically
> runs on 
>   file extension -> MIME type -> type handler
> We know that a document is xslt not because of its top-level
> element but because it is .xsl or .xslt.

That's what keeps us from calling an (XSLT document that generates
XHTML) an (XHTML document) merely because its root element is in the
XHTML namespace.  

> The obvious way to have access to namespace precis in
> a document (saved as a file) is to bubble up all namespace
> declarations to the top-level element.

I'd like to see that as more common practice, but don't expect it to
happen very often except in stylesheets and single-namespace documents.

> But if we need to canonicalize our documents in this way
> in order to have the namespace details in a convenient
> place for a webserver to re-extract it, why not just
> send the document like that in the first place, and let
> the application decide how to handle it? 

If you're storing XML as files, then that's reasonable - unless you're
serving masses of documents to clients which really need to know in
advance.  If that's the case, I'd recommend the server inspect the
documents (if they're static), and cache the results.  It'll make
content-negotiation and querying groups of doucments a lot easier, even
if the list of namespaces per se isn't going to help the client.

> It seems to me that "best practise" XML should include
> having xmlns:* declarations for all namespaces used
> in the document at the top level element, even if 
> the namespaces are used by default declarations
> within the document rather than the dummy prefixes
> at the top-level.

I agree, but don't see much way of promoting it.  Common XML makes
similar though slightly different recommendations, which have been
well-received by the few people who've read it.  (~200 visits a month.)

> Would it make processing and dispatching easier if
> XML tools did this?

Yes, though I don't think it's necessary to make the xmlns feature
useful for content-negotiation.
Simon St.Laurent
Ring around the content, a pocket full of brackets
Errors, errors, all fall down!


News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 2001 XML.org. This site is hosted by OASIS