Content model probs

tconway at walldata.com tconway at walldata.com
Fri May 14 19:15:44 BST 1999


You could define something like
<!ELEMENT tag (#PCDATA | XAndOrY)
<!ELEMENT XAndOrY (X?, Y*)


This requires one more element than you wanted, but it approximates what you
were looking for.

Tomás.

	-----Original Message-----
	From:	Leigh Dodds [SMTP:ldodds at ingenta.com]
	Sent:	Friday, May 14, 1999 2:50 PM
	To:	xml-dev
	Subject:	Content model probs

	Hi,

	I've being toying with a content model now and I think my brain 
	must be overloaded because I can't think of the best way to 
	format it so it'll parse.

	Basically I want to say that a tag should:

	1. Contain #PCDATA, *OR*
	2. an optional tag X followed by zero or more occurences of tag Y

	I had thought something like : (#PCDATA|(X?, Y*)
	but that doesn't seem to parse.

	At the moment I've had to settle on (#PCDATA|X|Y)* just so I 
	can continue working, and manually check for the moment that 
	I'm building documents which I consider legal.

	Any of you XML gurus got any suggestions?

	Thanks!

	L.

	p.s. A variation I'd also like to consider is changing the model 
	such that 2. (above) becomes:

	2. zero or more occurences of X, followed by zero or more occurences

	of Y.

	In this case X,Y can be interspersed. In the former, X *must* be
before 
	Y if its provided.

	==================================================================
	    "Never Do With More, What Can Be Achieved With Less"
					---William of Occam
	==================================================================
	Leigh Dodds                             Eml:  ldodds at ingenta.com
	ingenta ltd                             Tel:  +44 1225 826619
	BUCS Building, University of Bath       Fax:  +44 1225 826283
	==================================================================


	xml-dev: A list for W3C XML Developers. To post,
mailto:xml-dev at ic.ac.uk
	Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on
CD-ROM/ISBN 981-02-3594-1
	To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
	(un)subscribe xml-dev
	To subscribe to the digests, mailto:majordomo at ic.ac.uk the following
message;
	subscribe xml-dev-digest
	List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1
To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)




More information about the Xml-dev mailing list