The W3C Web API working group has posted the second public working draft of the Selectors API. "It is often desirable to perform script and or DOM operations on a specific set of elements in a document. Selectors [Selectors], mostly used in CSS [CSS21] context, provides a way of matching such a set of elements. This specification introduces two methods which take a group of selectors (often simply referred to as selector) as argument and return the matched elements as result." The spec offers the following JavaScript example:
function resolver(str) { var prefixes = { h: "http://www.w3.org/1999/xhtml", g: "http://www.w3.org/2000/svg"} return prefixes[str]; } var a = document.matchAll("h|div > g|svg", resolver); var b = document.matchSingle("div.foo.bar");