Duplicate of http://yuilibrary.com/projects/yui2/ticket/2529061 (but that's for YUI2).

The following snippet are additional public methods for Stylesheet. disableRule(match) allows you to temporarily turn off some of the rules in the Stylesheet; match is a string or RegExp to compare to
the selectors in the Stylesheet. enableRule(match) turns them back on again.

Although this is in YUI2.8, it might be good to have in 3 too - I'll file a separate ticket.

This doesn't fix the !important bug issues with Opera (http://yuilibrary.com/forum/viewtopic.php?f=89&t=4304&start=0&hilit=stylesheet)

There's also an extra var _disabledRules in the constructor.

[code]
/**

• Enable a particular rule (or several) that's previously been disabled.
• The selector parameter can be a RegExp; each rule matching the pattern
• will be enabled
• @param sel {String} String or RegExp to match to selectors to enable
• @method enableRule
• @return {StyleSheet} the StyleSheet instance
• @chainable
• /

enableRule : function (sel) {

var i,
disabled = _disabledRules,
toEnable = [],
thisToEnable,
idx;

for (i in disabled) {

if (YAHOO.util.Lang.isString(i) && i.match(sel) !== null) {

toEnable.push(i);
}

}

for (i=0; i<toEnable.length; i++) {

idx = sheet[_rules].length;
thisToEnable = disabled[toEnable[i]];

this.set(thisToEnable.selectorText,thisToEnable.css);
cssRules[i] = disabled[toEnable[i]];
delete disabled[toEnable[i]];

}

return this;

},

/**

• Disable a particular rule (or several) that's currently in the Sheet.
• The selector parameter can be a RegExp; each rule matching the pattern
• will be disabled
• @param sel {String} String or RegExp to match to selectors to disable
• @method disableRule
• @return {StyleSheet} the StyleSheet instance
• @chainable
• /

disableRule : function (sel) {

var i, j = 0,
enabled = cssRules,
toDisable = [],
idx;

for (i in enabled) {

if (YAHOO.util.Lang.isString(i) && i.match(sel) !== null && enabled[i].style.cssText) {

j++;
}

for (i=0; i<toDisable.length; i++) {

this.unset(toDisable[i]);
delete enabled[toDisable[i]];

}

return this;

}
[/code]