Re: EMBED (Re: HTML 2.0 specification)

Terry Allen (terry@ora.com)
Fri, 2 Sep 94 17:22:19 EDT

| About embed -- compare the NOTATION facility in SGML.
| It's imortant that you don't break SGML conformance, or, if you do, that
| it is a conscious decision. You can't simply embed arbitrary data,
| although if it is encoded in an SGML-safe way that's acceptable.
| E.g. you have to watch out for </ occurring in it.

The MIME type ought to take care of NOTATION issues; that is,
the MIME type should be mapped to the appropriate NOTATION if
need be. The arbitrary data need not be parsed; you could insert it
the rendering stage, after the parse, although if the content
turned out to be SGML you'd have to start a new parse (as though
it were a SUBDOC) and insert the rendered contents of that
second parse.

It is true that if arbitrary characters are dumped into an
element (even a CDATA one) and </ occurs there will be a parsing error.
One could get around this by inserting CDATA marked section
delimiters around EMBEDded data:

<p>foo
<![ CDATA [
this is some </test text
]]>
end of para.</p>

This does not work if the CDATA marked section occurs in a
CDATA element, I learn by experiment. 

-- 
Terry Allen  (terry@ora.com)   Editor, Digital Media Group
O'Reilly & Associates, Inc.    Sebastopol, Calif., 95472