- From: Mikko Rantalainen <mikko.rantalainen@peda.net>
- Date: Thu, 15 Sep 2005 12:38:17 +0300
- To: www-style@w3.org
Laurens Holst wrote: > Malcolm Rowe schreef: >> >>Can @required be implemented in such a way that it is useful with >>browsers that don't understand it, or do we have to wait until all >>CSS-capable browsers implement @required before we start using it? >> >>Because it seems to me that a naïve implementation (or design), i.e.: >> >>@required { >> color: black; >> background: white; >>} >> >>would actually result in none of the rules being applied in today's >>UA's. Or am I mistaken? >> > > And we’re back to my point at: > > http://www.grauw.nl/articles/css-faq.php#how-long Not quite but close. The @required feature would be one that style authors could safely use immediately after even a one UA supported it. Unlike using "position: fixed" today or "border-radius" with big values without specifying huge amount of padding for everybody in the near future. Granted, there's the chicken and egg problem - why should I as a style author use @required if everything inside it *will* be ignored by all current UAs? And if nobody uses @required why should an UA implement it? Some CSS rules make sense only when combined with other rules and there's no way to correclty handle this situation currently. The @required *seems* to be a way out. I'm happy to hear how you would solve the following rules without @required: selector { padding: 0.25em; } @required { selector { padding: 0.75em; border-radius: 1em; } } Note that if I instead write selector { padding: 0.75em; border-radius: 1em; } then UAs without implementation of 'border-radius' will be huge amount of padding which looks bad. On the other hand, if I use rule like selector { padding: 0.25em; border-radius: 1em; } then my style looks okay in UAs which support 'padding' but do not support 'border-radius', but UAs that support both, might end up clipping part of the actual content because of the rounded corners. I consider @required feature important for shortening the time it requires before *new* CSS features can be used in live. Many new CSS features require setting multiple properties to get maximum out of them. -- Mikko
Received on Thursday, 15 September 2005 09:38:32 UTC