Query Selector for IE

querySelectorForIE.js

!('querySelectorAll' in document) && ('contains' in document.documentElement) && (function (window, document) {
	var
	documentHead = document.getElementsByTagName('head')[0],
	querySelectorElement          = document.createElement('style'),
	querySelectorPrototypeElement = document.createElement('style');

	documentHead.insertBefore(querySelectorElement         , documentHead.firstChild);
	documentHead.insertBefore(querySelectorPrototypeElement, documentHead.firstChild);

	function querySelectorAll(selector) {
		var index = __querySelectorResult.length, result;

		__querySelectorResult[index] = [];

		querySelectorElement.styleSheet.cssText = selector + '{-ms-query-selector:expression(__querySelectorResult[' + index + '].push(this))}';

		scrollBy(0, 0);

		querySelectorElement.styleSheet.cssText = '';

		result = __querySelectorResult.splice(index, 1)[0];

		if (this.parentNode) {
			for (index = 0; result[index]; ++index) {
				if (!this.contains(result[index])) {
					result.splice(index--, 1);
				}
			}
		}

		return result;
	}

	function querySelector(selector) {
		var results = querySelectorAll.call(this, selector);

		return results && results[0];
	}

	function matchesSelector(selector) {
		var
		results = querySelectorAll.call(document, selector),
		resultsLength = results.length,
		resultsIndex = -1;

		while (++resultsIndex < resultsLength) {
			if (results[resultsIndex] === this) {
				return true;
			}
		}

		return false;
	};

	window.__querySelectorResult = [];

	document.querySelectorAll = querySelectorAll;
	document.querySelector = querySelector;
	document.matchesSelector = matchesSelector;

	querySelectorPrototypeElement.styleSheet.cssText = '*{-ms-query-selector-prototype:expression(!this.querySelectorAll && (this.querySelectorAll = querySelectorAll) && (this.querySelector = querySelector) && (this.matchesSelector = matchesSelector))}';
})(window, document);