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Re: Error Message Feedback: "valid 1.1"

From: Chris Lilley <chris@w3.org>
Date: Mon, 30 May 2005 17:17:11 +0200
Message-ID: <15810179102.20050530171711@w3.org>
To: Henri Sivonen <hsivonen@iki.fi>
Cc: www-validator@w3.org

On Monday, May 30, 2005, 4:07:46 PM, Henri wrote:

HS> On May 30, 2005, at 16:08, Chris Lilley wrote:

>> On Saturday, May 28, 2005, 1:38:24 PM, Henri wrote:
>>
>> HS> On May 27, 2005, at 19:31, Chris Lilley wrote:
>>
>>>> Okay. I suggest that it should use a lookup table of namespaces (to
>>>> detect that its SVG) and then, having determined that it is SVG, it
>>>> could usefully get more info from baseProfile (Tiny, Basic or Full)
>>>> and
>>>> version (1.0, 1.1, 1.2).
>>
>> HS> What if the DTD does not match?
>>
>> HS> <!DOCTYPE svg "BogoDTD" "http://example.com/bogo.dtd">
>> HS> <svg version     = "1.1"
>> HS>         baseProfile = "tiny"
>> HS>         xmlns       = "http://www.w3.org/2000/svg">
>> HS>   <bogo/>
>> HS> </svg>
>>
>> Well then it wouldn't be valid :) as the DTD validator would report.

HS> How do you know bogo.dtd does not make that valid?

You don't, except by trying it. Any more than you know that

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE svg 
PUBLIC "-//W3C//DTD SVG 1.1 Tiny//EN"
 "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-tiny.dtd"[
 <!ENTITY % SVG.svg.extra.content "| bogo" >
 <!ELEMENT bogo EMPTY >
 ]>
    <svg version     = "1.1"
        baseProfile = "tiny"
        xmlns       = "http://www.w3.org/2000/svg">
        <bogo/>
    </svg>

is valid, except by trying. (Its valid to the DTD, but is not conformant
because the bogo element was put in the SVG namespace).

>> HS> The basic problem is of course that DTD validation does not answer
>> the
>> HS> question "Does document D conform to grammar G?" but answers the
>> HS> question "Does document D conform the grammar it happens to  
>> declare?"
>>
>> Right. The point is, how do you get the name of that grammar.

HS> By focusing on the first question and asking the user to select the
HS> schema to validate against.

OK, fair enough.

>> HS> (RELAX NG validation would answer the first question.)
>>
>> Yes it would. I would be very interested to see a RelaxNG validator
>> option.

HS> http://hsivonen.iki.fi/validator/? 
HS> schema=http%3A%2F%2Fwww.w3.org%2FGraphics%2FSVG%2F1.2%2Frng%2FTiny 
HS> -1.2%2FTiny-1.2.rng&laxtype=yes

Thanks! What does laxtype=yes do?

>> Note that in RelaxNG (and in W3C XML Schema) the pointer to the
>> schema is not contained, necessarily, in the document instance.

HS> I consider that a desirable feature of RELAX NG. I think doctype and
HS> schemaLocation are design bugs.

I agree with that, especially since I have become more convinced of the
utility of validating to different schemas for different purposes.



-- 
 Chris Lilley                    mailto:chris@w3.org
 Chair, W3C SVG Working Group
 W3C Graphics Activity Lead
Received on Monday, 30 May 2005 15:17:16 GMT

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