- From: Nir Dagan <nir@nirdagan.com>
- Date: Tue, 22 Feb 2000 18:13:34 -0500
- To: Matthew Brealey <thelawnet@yahoo.com>, www-html@w3.org
At 05:21 PM 2/22/00 -0500, Matthew Brealey wrote: >However, I am perhaps of the view that bidirectionality is better suited >to style sheets anyway, since it is concerned with the visual rendering of >documents, not their structure, and perhaps dir and BDO should be >deprecated for the direction and unicode-bidi properties. Although BiDi is indeed rendering, it is essential for readability. This makes it quite different from <font> for example: There is the "rule" that HTML documents should be rendered correctly if the user turns off style sheets. Having BiDi support in HTML markup is important as it is assumed that some future light weight HTML renderers will have no support for style sheets. With XML the situation is different, as default user's style cannot address author defined elements. Indeed, the approach in XML1.0 is not to have generic directionality markup, but to rely on style sheets and/or Unicode's special characters. This makes sense since generic XML needs a style sheet anyway, and is often machine generated (see point below) As I pointed out in an earlier message, these Unicode characters may be used in HTML but require typically superior software to produce without errors. On the other hand, from the point of view of programming a browser, supporting the Unicode directionality control characters only or also the HTML markup is essentially the same programming effort. From a practical point of view, browsers that support BiDi are often modular, that is have an optional BiDi module. This reduces the cost for users who are not interested in BiDi support, who don't have to spend resources for an irrelevant job. This may support the view that all BiDi related markup will be in one HTML module. Thus my view is that HTML (including XHTML) differs from generic XML in that: 1. It should "work" without an author's style sheet. 2. It should be easier to write with primitive software. Therefore having directionality markup in HTML is a good thing. Also: 3. It would make sense to have all BiDi related HTML features in one module. Regards, Nir. =================================== Nir Dagan Assistant Professor of Economics Brown University Providence, RI USA http://www.nirdagan.com mailto:nir@nirdagan.com tel:+1-401-863-2145
Received on Tuesday, 22 February 2000 18:10:51 UTC