[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Why validate? (was Re: Parser compliance)

• From: David Megginson <david@m...>
• To: xml-dev@i...
• Date: 18 Nov 1999 08:26:45 -0500

ht@c... (Henry S. Thompson) writes:

> Maybe I was overly influenced by the fact that my first exposure to
> pointy brackets was in the context of SGML, but I think validation is
> pretty fundamental.

I don't think that anyone is arguing against the usefulness of
validation -- Tim's point is DTDs and other formal schemas alone
supply only a small subset the validation necessary for any
real-world information exchange.

> A DTD is like a contract, it helps both clients and service
> providers to maintain a satisfactory working relationship.

It's a very simply contract, though; consider the following DTD:

 <!ELEMENT song (title, composer)>
 <!ELEMENT title (#PCDATA)>
 <!ELEMENT composer (#PCDATA)>

Here's a document that's valid according to that DTD, and that doesn't 
fiddle with the DTD in its internal subset:

 <?xml version="1.0"?>
 <!DOCTYPE song SYSTEM "song.dtd">
 <song>
  <title>David Bowie</title>
  <composer>Let's Dance</composer>
 </song>

As Eliot, Tim, and I have all mentioned (in different contexts), the
primary contract *has* to be the human readable documentation, even
though the DTD is useful for detecting a certain subset of problems.


All the best,


David

-- 
David Megginson                 david@m...
           http://www.megginson.com/

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

• References:
  • Re: Parser compliance
    • From: Tim Bray <tbray@t...>
  • Re: Parser compliance
    • From: David Megginson <david@m...>
  • Why validate? (was Re: Parser compliance)
    • From: ht@c... (Henry S. Thompson)

• Prev by Date: Re: documenting schemas/DTDs
• Next by Date: Re: documenting schemas/DTDs
• Previous by thread: Why validate? (was Re: Parser compliance)
• Next by thread: Re: Why validate?
• Index(es):
  • Date
  • Thread