Re: proper use of validation icons

Michael A. Peters wrote:

> http://www.shastaherps.org/
>
> click the valid button (left navigation menu).
> See it vsalidate as xhtml 1.1 (the validator always gets xhtml even if
> your browser gets the html version)

Testing this on IE 8, I see an icon claiming HTML 4.01 validity. Clicking on 
the icon I get the response
"This document was successfully checked as XHTML 1.1!"
Do I need to say more?

Oh well, lets check on Firefox as well. Now I see a claim on XHTML 1.1 
validity, and clicking on it I get the same response as above. Yet the 
document is not an XHTML 1.1 document, as it has a different document type 
definition.

> Notice addition to DTD and use of attribute added in the source.

Yes indeed. They mean that the document's declared document type is not the 
XHTML 1.1 document type. Thus it is not "valid XHTML 1.1", whether it 
actually uses the added feature in markup of not

> Is that then a bug in the validator?

Yes, though I'm sure there are people who explain it as a feature. That 
happens for almost any bug in software.

If you take a copy of your document (as served to the validator or to 
Firefox) and change "1.1" in "-//W3C//DTD XHTML 1.1//EN" to, say, "1.2", you 
will get the validation response
"This document was successfully checked as -//W3C//DTD XHTML 1.2//EN!"

This demonstrates what the validator is actually doing. It's a play on 
strings. It has a built-in list of strings that it recognizes as having 
special meanings. Otherwise it reports something absurd, like having tested 
against a catalogued document type definition by W3C.

Validation process should result in a statement saying whether the document 
is valid or not, in the latter case with a report of errors. The confusion 
arises from the misguided attempt to add something "user-friendly" or 
"practical" to that. Of course, a valid document need not have anything to 
do with HTML, so calling a purported HTML document "valid" does not say 
anything about its relationship with any HTML specification or document 
types defined in such specifications.

But no addition to "valid" or "not invalid, due to errors..." is needed for 
any appropriate use of validation. If someone uses a validator, he surely 
needs to understand at some level what validation is and know for himself 
what document type definition he is using. And it can always be checked by 
looking at the start of the document. In your case, anyone who has 
prerequisites for proper use of a markup validator will immediately see that 
your valid document does not declare the XHTML 1.1 document type. Instead, 
it declares one that is derived from it with the addition of a declaration.

-- 
Yucca, http://www.cs.tut.fi/~jkorpela/

Received on Monday, 8 June 2009 06:50:29 UTC