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Re: bidi discussion list was: Bidi Markup vs Unicode control characters

From: Felix Sasaki <fsasaki@w3.org>
Date: Tue, 16 Aug 2005 17:21:58 +0900
To: "Martin Duerst" <duerst@it.aoyama.ac.jp>, "www-international@w3.org" <www-international@w3.org>
Message-ID: <op.svldiwahx1753t@ibm-60d333fc0ec>



On Mon, 15 Aug 2005 17:09:01 +0900, Martin Duerst <duerst@it.aoyama.ac.jp>  
wrote:

>  >
>  >Bidi properties are similar, but there we have gone the other way:
>  >generic XML doesn't have bidi attributes and nobody was even talking
>  >about adding them (unlike for links, where XLink has been attempted),
>  >so we had no choice but to add bidi properties to CSS.
>
> It may be that this gap is filled in by the ITS WG. Whether their
> result will be used as 'generic' bidi attributes (in the sense that
> eventually every XML stack should just understand them) or just
> as a 'preferred' set of attributes with CSS glue for rendering
> remains to be seen. Maybe a bit of both.
>


The ITS WG has a requirement for Bidi, owned by Richard; see
http://esw.w3.org/topic/its0505ReqBidi

The question whether Bidi control with markup should be realized within  
the XML stack is difficult to answer. For all "data centered" applications  
of XML which are not meant to be read by humans, Bidi control does not  
seem to be a relevant feature, so I guess it would be hard if not  
impossible to convince the various working groups e.g. in the architecture  
domain to accept Bidi attributes or even process them.

A related topic the ITS working group is working on is that ITS should  
have a limited impact on existing markup schemes, see
http://esw.w3.org/topic/its0505LimitImpact
If Bidi would be implemented in the way described in the wiki, possibly  
there would be no need to change existing markup vocabularies for the  
additional Bidi features.

-- Felix

>  >That's why CSS (in section 9.10
>  >http://www.w3.org/TR/CSS21/visuren.html#direction) indeed tells people
>  >not to use these properties. In general, creators of an XML-based
>  >format should tell how the elements/attributes of their formats map to
>  >CSS 'direction' & 'bidi-override' properties and other people should
>  >not override them.
>
> Yes, this is a very important point. A stylesheet for an XML document
> should just include the stylesheet for the bidi properties of the
> relevant document type, and not mess around with them at all, except
> for some very special situations (the typical example is to render
> Hebrew-encoded Yiddish with a font that substitutes Latin glyphs;
> in that case, the directionality needs to be tweaked).
>
>
>  >> It had not occurred to me that people were interpreting it to mean  
> that
>  >> css implementers would intentionally choose not to support it or that
>  >> W3C was endorsing such a view. That would be counter to goals for
>  >> internationalization and making the web accessible to all.
>  >
>  >The CSS2 spec used to say that a program was allowed to ignore the
>  >properties in the case of HTML documents, but it doesn't say that
>  >anymore. There is no difference anymore between HTML and XML in that
>  >respect.
>
> When and why has this been changed? To me, the change does not make
> sense, and should be reverted.
>
>
>  >Individual profiles can still say which properties are optional and
>  >both the Mobile Profile and the Print Profile say the bidi properties
>  >are not required for conformance. I believe that is because both
>  >profiles are in practice only used with XHTML1 and thus the properties
>  >aren't needed.
>
> If that is the case, this would indeed make sense.
>
>
> Regards,    Martin.
Received on Tuesday, 16 August 2005 08:22:12 GMT

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