- From: Boris Zbarsky <bzbarsky@mit.edu>
- Date: Tue, 22 Nov 2005 20:17:55 -0600
- To: Lachlan Hunt <lachlan.hunt@lachy.id.au>
- CC: www-style@w3.org
Lachlan Hunt wrote: > However, it doesn't seem > to be defined how a UA should handle such rules in a UA stylesheet. Correct. But let's look at it another way. What _is_ a UA stylesheet? What does it mean to have a !important rule there? > To test this, I tried the following rules in Firefox: The fact that Firefox has an actual CSS file as a UA stylesheet is an implementation detail. It could also have been done completely as a binary file (eg fastloaded version of ua.css) or even as part of the C++ code. Modifying this file is equivalent to making changes to the C++ and recompiling the browser -- all you're doing is changing the rendering engine itself. > I then restarted Firefox and was given red headings. So, clearly > Mozilla is treating UA !important rules above all others, including user > !important stylesheets. Yes, when Firefox needs a way to force the rendering engine to have a particular cascaded value for a property this is how it happens to do it. That's subject to change without notice, of course. > While it is unlikely that a vendor would put > !important rules in their stylesheet by default, the result should be > well defined in such cases. Why? What's the interoperability benefit? Keep in mind that the reason there is a spec is to ensure interoperability. -Boris
Received on Wednesday, 23 November 2005 02:18:06 UTC