I did make a test implementation of dir=uba in Firefox and you can download this from here: http://www.diwan.com/w/Minefield.zip. And I list the issues I had here: http://ironymark.diwan.com/2010/06/hacking-diruba/. From my experience, I would agree with Aharon that dir=uba should not be implemented as it has been specified. The main issues for me (apart from what has been discussed) is that this is a feature in markup without a direct equivalent in CSS. As I understand it, the way the Firefox code works (and other browser projects I have worked on) is to map HTML attributes that affect layout (e.g. dir=rtl) into CSS and layout on the CSS alone. However, dir=uba breaks this method. The implementation would not be easy and a special case only for dir=uba. I would also expect this can create performance issues as the layout could not be optimised on the CSS rules alone. Also, it relies on different inheritance rules to CSS. Specifically: |dir=uba| sets |unicode-bidi| to plaintext isolate and |unicode-bidi| is a CSS attribute that does not inherit. But dir=uba is inherited in markup so it requires |unicode-bidi| to be inherited. This needs to be done explicitly in code and not to rely on normal CSS inheritance rules. I think this is a lot of work for a feature that, I believe, has limited benefit and can be adequately described using JavaScript. Again, it falls down to the use-case. Unless there is an overwhelming need for this feature and I would not want to jeopardize the whole proposal for this. Adil
Received on Tuesday, 24 August 2010 21:37:52 UTC