Obsolete
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
The obsolete CSSStyleSheet
interface's
addRule()
legacy method adds a new rule to the
stylesheet. You should avoid using this method, and should instead use the more standard
insertRule()
method.
Syntax
var result = cssStyleSheet.addRule(selector, styleBlock, index);
Parameters
selector
- A
DOMString
specifying the selector portion of the CSS rule. The default is the stringundefined
. styleBlock
- A
DOMString
indicating the style block to apply to elements matching theselector
. The default is the stringundefined
. index
Optional- An optional index into the stylesheet's
CSSRuleList
at which to insert the new rule. Ifindex
is not specified, the next index after the last item currently in the list is used (that is, the value ofcssStyleSheet.cssRules.length
).
Return value
Always returns -1.
Note that due to somewhat estoteric rules about where you can legally insert rules,
it's possible that an exception may be thrown. See insertRule()
for more information.
Usage notes
This method is implemented by browsers by constructing a string using the template
literal `${selector}{${styleBlock}}`
, then passing it into the standard
insertRule()
method.
Therefore, given existing code such as the following:
cssStyleSheet.addRule(selector, styles, 0);
You can rewrite this to use the more standard insertRule()
like this:
cssStyleSheet.insertRule(`${selector} {${styles}}`, 0);
Specifications
Specification | Status | Comment |
---|---|---|
CSS Object Model (CSSOM) The definition of 'CSSStyleSheet.addRule()' in that specification. |
Working Draft |
Browser compatibility
BCD tables only load in the browser