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RE: [CTG] Draft 2008-11-07 / inconsistencies / validation

From: Rotan Hanrahan <rotan.hanrahan@mobileaware.com>
Date: Thu, 13 Nov 2008 08:04:26 -0000
Message-ID: <D5306DC72D165F488F56A9E43F2045D301CBE2CA@FTO.mobileaware.com>
To: <casays@yahoo.com>, <public-bpwg-ct@w3.org>
Cc: <rotan.hanrahan@mobileaware.co>

Ignoring the devices that don't even reach the level of sophistication
represented by the DDC, I'd have to agree that characterising
well-formedness as a minimum requirement would seem to be basically OK.
So long as we acknowledge that there are devices that may behave
incorrectly even if the markup is well formed, and that in such cases it
is legitimate for an adaptation process to further constrain the
well-formedness of the content it produces.

As for producing content that is valid according to the standards (as
opposed to vendor-specific definitions, if known), that would be too
limiting. I'd go with "SHOULD be valid according to the markup
specifications known to be supported by the browser", which doesn't
distinguish between standard and proprietary specifications, nor does it
elaborate on how one comes to know about the supported markup. On that
latter point, you cannot rely on the Accept header because this does not
necessarily indicate the additional features supported by the browser,
nor any implementation constraints (e.g. the level of nesting of tables)
that may exist. For that information you need to look elsewhere, which
is what the DDR technology is all about.

So it seems we may have found a locus of agreement. :)


-----Original Message-----
From: public-bpwg-ct-request@w3.org
[mailto:public-bpwg-ct-request@w3.org] On Behalf Of Eduardo Casais
Sent: 12 November 2008 14:29
To: public-bpwg-ct@w3.org
Cc: rotan.hanrahan@mobileaware.co
Subject: RE: [CTG] Draft 2008-11-07 / inconsistencies / validation

> I was trying to say is that well-formedness
> is not a sufficient condition. Requiring
> that you must have a space before / means
> that well-formedness according to the
> specification may not be well-formed with
> respect to what's acceptable to the device.
> So running the content through a standard WF
> validator doesn't necessarily give you the
> "all clear". 

You mentioned browsers that expect a space before the tag closing. Some
browsers are peculiar about enclosing attribute values with single
quotes instead of double quotes (Openwave browsers come to mind). But in
all these cases, the quirks do not contradict the well-formedness of the
markup. In other words, requiring well-formed content is perhaps not
enough, since additional constraints must be satisfied, but it is a
minimum. As I suggested:

    "Can we state that the transformed
    content returned to the terminal must
    at least be well-formed (following XML

I reiterate my question: does anybody know of a browser that will
process content properly _only_ if it is _not_ well-formed -- e.g.
omitting the XML declaration, leaving tags open, parsing only uppercase
element names, duplicating attributes for the same element, overlapping
elements instead of nesting them, whatever? 

If not, the requirement for well-formedness could indeed constitute a
minimum requirement -- not an "all clear", but a "seems basically ok".

> Validation, however, is another matter...

I already agreed that requiring validation (in the XML sense) is
probably too much. 


Received on Thursday, 13 November 2008 08:05:08 UTC

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