index.js

require('util.polyfill');

var RE_TRIM = /^\s+|\s+$/g;

/**
 * Check if 'element' has class 'clas'
 * @param {Element} element
 * @param {String} clas
 * @return {Boolean}
 */
exports.hasClass = function(element, clas) {
	if (element.classList != null) {
		return element.classList.contains(clas);
	} else {
		var classes = element.className.replace(RE_TRIM, '').split(' ');
		return classes.indexOf(clas) >= 0;
	}
};

/**
 * Check if 'element' has a class matching 'pattern'
 * @param {Element} element
 * @param {String} pattern
 * @return {String}
 */
exports.matchClass = function(element, pattern) {
	var classes = element.className.replace(RE_TRIM, '').split(' ')
		, clas;
	for (var i = 0, n = classes.length; i < n; i++) {
		clas = classes[i];
		if (clas.indexOf(pattern) !== -1) {
			return clas;
		}
	}
	return '';
};

/**
 * Add class 'clas' to 'element'
 * @param {Element} element
 * @param {String} clas
 */
exports.addClass = function(element, clas) {
	if (element.classList != null) {
		element.classList.add(clas);
	} else {
		element.className += ' ' + clas;
	}
};

/**
 * Remove class 'clas' from 'element'
 * @param {Element} element
 * @param {String} clas
 */
exports.removeClass = function(element, clas) {
	var c, classes;
	if (clas) {
		if (element.classList != null) {
			element.classList.remove(clas);
		} else {
			var classes = element.className.replace(RE_TRIM, '').split(' ')
				, results = [];
			for (var i = 0, n = classes.length; i < n; i++) {
				if (classes[i] !== clas) results.push(classes[i]);
			}
			element.className = results.join(' ');
		}
	}
};

/**
 * Toggle class 'clas' on 'element'
 * @param {Element} element
 * @param {String} clas
 */
exports.toggleClass = function(element, clas) {
	if (exports.hasClass(element, clas)) {
		exports.removeClass(element, clas);
	} else {
		exports.addClass(element, clas);
	}
};

/**
 * Replace class 'clasOld' with 'clasNew' on 'element'
 * @param {Element} element
 * @param {String} clas
 */
exports.replaceClass = function(element, clasOld, clasNew) {
	if (clasOld) {
		if (clasNew) {
			element.className = element.className.replace(clasOld, clasNew);
		} else {
			exports.removeClass(element, clasOld);
		}
	} else if (clasNew) {
		exports.addClass(element, clasNew);
	}
};

/**
 * Add class 'clas' to 'element', and remove after 'duration' milliseconds
 * @param {Element} element
 * @param {String} clas
 * @param {Number} duration
 */
exports.addTemporaryClass = function(element, clas, duration) {
	exports.addClass(element, clas);
	setTimeout((function() {
		exports.removeClass(element, clas);
	}), duration);
};