ietf-xml-mime
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Re: External parsed entities (Re: Inconsistency between IETF and W3C...)

1999-11-29 05:22:03


MURATA Makoto wrote:

Chris Lilley wrote:
[someone] wrote:
The text/xml MIME type isn't limited to well-formed documents, but
rather
to XML entities (c.f. 2nd para under 3. XML Media Types of
http://www.ietf.org/internet-drafts/draft-murata-xml-01.txt); so the
following:

        Four score and seven years ago

is a valid text/xml body, but an XML processor will burp cuz there's
no root element.

This is a good point, which had escaped my notice before. Certainly, it
should be a requirement that text/xml (or the preferred application/xml,
which avoids silly crufty rules about charsets) is always a well formed
XML instance, and things thatare now well formed XML use a different
type.

In XML 1.0, an XML document can also become an external parsed entity.

Of course - that is not the problem. Rather the converse - an external
parsed entity is not necessarily a well formed document.

For example, consider an XML document as below:

<?xml version="1.0"?>
<test/>

Thats fine, I have no issue with that instance being labelled as
text/xml or application/xml. But I do have a problem with this being so
labelled:

hello world

In order to allow such an XML document, we have to use text/xml or 
application/xml
for external parsed entities.

No, that doesn't follow. You are driving a non-commutative relationship
backwards. Just because a well formed XML document can be used as an
external parsed entity (and can be labelled as text/xml or
application/xml), it does not follow that a non-well-formed thing can
also be so labelled. It should be labelled something else, like
application/xml-epe or whatever.

Which would then mean that valid MIME types for an epe would be
application/xml-epe or application/xml depending on whether the epe was
a well-formed document init own right, or not.

Dan Connolly wrote:
      Four score and seven years ago

is a valid text/xml body, but an XML processor will burp cuz there's
no root element.

Yes.  It must report a fatal error.  Even if we disallowed the use of text/xml
or application/xml for parsed entities, the world would not be free from 
incorrect
documents and fatal errors.

It is one thing for such errors to occur through mistakes. It is another
to encourage or mandate such errors, through labelling things
inappropriately.

--
Chris

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