Re: Why Doesn't IE5 use the DTD to Validate?

Subject: Re: Why Doesn't IE5 use the DTD to Validate?
From: Paul Prescod <paul@xxxxxxxxxxx>
Date: Thu, 01 Apr 1999 13:35:01 -0600
John Dreystadt wrote:
> I want to second the spirit of Paul's suggestion but not the letter. I
> think that sometimes the person running the browser will know if they
> want validation (Reader) and sometimes the Author will know. 

There is a subtle difference between my proposal and your understanding of
my proposal. I am not saying that the PI should be an instruction about
what the browser should do. As you say, that's up to the user and the
browser. I'm saying that there should be a declaration of the author's

In general, XML should avoid instructions such as "checkvalidity" in favor
of declarations such as "no-valid". Instructions put responsibility for
what actually happens in the hands of the author. Declarations put the
responsibility in the hands of the reader.

> I also believe that a PI that forces validation is useful for
> e-commerce situations.

In e-commerce situations it is the reciever that knows whether its policy
requires the document to be valid or not. The generator does not know the
receiver's policy. If I were coding a receiver I would ignore the
generator's instructions altogether!


I'm thinking that the declaration really belongs in the DTD itself. The
DTD should be able to say that it is 

<xml:correct valid> -- documents declaring conformance to this DTD must
have top to bottom XML 1.0 validity to be correct.

<xml:correct partial> -- documents declaring conformance to this DTD will
be correct only if they do not violate any element type or attribute
declarations but not all elements and attributes may be declared. If there
are no element type or attribute declarations then the document is not
checked beyond well-formedness.

Note that checking "correctness" is distinct from checking "validity" so
there is no conflict with the XML specification.
 Paul Prescod  - ISOGEN Consulting Engineer speaking for only himself

"Other Operating Environments Will Have Trouble Keeping up with Linux's
   International Data Corporation bulletin

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