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

Ken,

	While I see your point in terms of validation, I think that
Jonathan's argument is sound.
As a content provider, I can see little need for *client-side* validation,
except in certain special cases. Validation against a DTD is a check for
structural validity, and should be carried out by the author prior to
serving the document. As Jonathan notes, what is the client supposed to do
on receiving an invalid document? Popping up a Javascript alert box is not
acceptable, nor is refusing to show the page. We must work on the assumption
that the author validated the document. Also, validation by clients would
simply take too long and be too large a performance hit. Validation is for
author's to check their work, not for browsers to check their input. (These
arguments do not apply to well-formedness.)

	In your notes from the XML spec and Tim Bray's annotations I find
this note:

<TIMBRAY>
> Some members of the first
> generation of XML processors
> actually are both validating and
> non-validating. Usually, they have
> some way to turn the validating
> behavior on and off. Nothing in the
> spec rules this out, and it seems
> to be useful.
</TIMBRAY>

	To the best of my understanding (and I am sure Jonathan will correct
me once again if I am wrong) this is the design Microsoft used for their
browser. If authors want to use MSIE5 to validate their documents, they will
have to read the man pages to figure out how to turn validation on. But
users don't need validation client-side, they need it server-side.

> 1) Author: Visit the above Workshop page to find the relevant 
> JavaScript
> code to set the validOnParse flag. Of course, they have to 
> know about this
> page. (And, BTW, I couldn't get any of my examples, valid or 
> invalid, to
> work using the online demo; I had to download it to get it to work for
> anything but your weatherReport.xml. I got this msg online:
> 	Access is denied. 
> 	File: 
> http://members.home.com/kensall/tests/collection1pubbugs.xml
> 	Line: 0, Position: 0, ErrorCode: 0x80070005)

	I think this is probably a security error; you cannot load documents
from other domains.

> 4) End User: Must have JavaScript Enabled on. Big assumption here.

	Hmmm...do a lot of end users turn scripting off? My impression has
been the opposite but I have not done any research. I think this is probably
a safe assumption.

Hope this helps

Regards,

D-

**********************************************************************

Daniel Austin, Director of Development, Creative Services, CNET
daniela@xxxxxxxx <mailto:daniela@xxxxxxxx> 415-395-7800 x1438
"To change the old into the new, and the shapes of things to come..." 




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