Re: Deferring CSS load for unmatched Media Queries

On 2/4/13 11:56 PM, Tab Atkins Jr. wrote:
> 1. Essential stylesheets.  All current stylesheets are in this
> category by default.  Essential stylesheets load eagerly, block script
> execution during parsing, etc.

Not all current stylesheets are in this category by default.  For 
example, at least in Gecko alternate stylesheets are not in this category.

The behavior of Gecko for alternate stylesheets is that we do not start 
loading them until there are no pending non-alternate loads (though we 
may be changing things so that they're even lower priority) and we do 
not block script execution on them.

As a separate issue, it's not obvious to me whether it's better to have 
a null OM or a CSSStyleSheet object that throws when you try to examine 
its rules (but not if you just want to check whether it's disabled, 
say).  Gecko currently does the latter, I believe, but there are 
reasonable arguments both ways...

-Boris

Received on Tuesday, 5 February 2013 00:14:00 UTC