xml-dev - Re: Last minute request for BASE64 section support in XML 1.0

["Don Park" <donpark@quake.net>]

Chris,

>I'm not very thrilled with the way notation works, but given Dan
>Connolly's comments about moving MIME towards a URL-based mechanism,
>then MIME types can be used as notation system identifiers.

That still leaves encoding format to be specified.  While I have focused on
BASE64, I would prefer to leave the door open for other encoding formats.

>You can not expect to process XML documents in total ignorance of the
>DTD.  You can expect to process many XML documents with only the
>internal subset, and you can mandate for your application that
>notation declarations be in the internal subset.  I don't see why
>
><!DOCTYPE foo [
><!NOTATION base64 ...>
>...
>]>
><binary-data notation="base64">...</binary-data>

I was not aware that non-validating XML parsers are required to process the
internal DTD subset.  Is this true?  Even if it was true, how could an
application tell that notation="base64" attribute indicates that the content
is binary data?  Should we treat "base64" as a special notation name?

><!DOCTYPE foo [
>...
>]>
><binary-data><![BASE64[...]]></binary-data>

Perhaps I did not make it clear.  I have already gave up on the idea of
using BASE64 section after realizing that it will conflict with SGML.

Please read my description of my latest proposal in my last message post.
It does look similar to your "notation='base64'" idea without requiring the
use of notation.  It allows a non-validating parser to detect whether an
element's content is binary data and, if so, determine its encoding format
and its MIME type.  A very friendly parser could take that information and
return an object which could be an image, sound, or even a Java object if
the data is Java serialization data.

What I just described is already working in my application.  I simply pass
the info to Java Activation Framework (JAF) to get mimetype specific handler
for the decoded data.  I am hoping to provide some of the code as reference
implementation for the upcoming XML-Binary proposal.

Regards,

Don Park
http://www.quake.net/~donpark/index.html

-----Original Message-----
From: Chris Maden <crism@ora.com>
To: xml-dev@ic.ac.uk <xml-dev@ic.ac.uk>
Date: Tuesday, February 10, 1998 1:28 PM
Subject: Re: Last minute request for BASE64 section support in XML 1.0


>[Don Park]
>
>is unacceptable, but
>
>
>is acceptable.  The first even provides for a measure of extensibility
>(!) that the second lacks.
>
>This discussion should probably be moved to the XML SIG, as it
>involves the design of XML, not its implementation.
>
>-Chris
>--
><!NOTATION SGML.Geek PUBLIC "-//Anonymous//NOTATION SGML Geek//EN">
><!ENTITY crism PUBLIC "-//O'Reilly//NONSGML Christopher R. Maden//EN"
>"<URL>http://www.oreilly.com/people/staff/crism/ <TEL>+1.617.499.7487
><USMAIL>90 Sherman Street, Cambridge, MA 02140 USA" NDATA SGML.Geek>
>
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