常用JS兼容问题工具

//浏览器检测
(function () {
	window.sys = {};
	var ua = navigator.userAgent.toLowerCase();	
	var s;		
	(s = ua.match(/msie ([\d.]+)/)) ? sys.ie = s[1] :
	(s = ua.match(/firefox\/([\d.]+)/)) ? sys.firefox = s[1] :
	(s = ua.match(/chrome\/([\d.]+)/)) ? sys.chrome = s[1] : 
	(s = ua.match(/opera\/.*version\/([\d.]+)/)) ? sys.opera = s[1] : 
	(s = ua.match(/version\/([\d.]+).*safari/)) ? sys.safari = s[1] : 0;
	
	if (/webkit/.test(ua)) sys.webkit = ua.match(/webkit\/([\d.]+)/)[1];
})();

//DOM加载
function addDomLoaded(fn) {
	var isReady = false;
	var timer = null;
	function doReady() {
		if (timer) clearInterval(timer);
		if (isReady) return;
		isReady = true;
		fn();
	}
	
	if ((sys.opera && sys.opera < 9) || (sys.firefox && sys.firefox < 3) || (sys.webkit && sys.webkit < 525)) {
		//无论采用哪种，基本上用不着了
		/*timer = setInterval(function () {
			if (/loaded|complete/.test(document.readyState)) { 	//loaded是部分加载，有可能只是DOM加载完毕，complete是完全加载，类似于onload
				doReady();
			}
		}, 1);*/

		timer = setInterval(function () {
			if (document && document.getElementById && document.getElementsByTagName && document.body) {
				doReady();
			}
		}, 1);
	} else if (document.addEventListener) {//W3C
		addEvent(document, 'DOMContentLoaded', function () {
			fn();
			removeEvent(document, 'DOMContentLoaded', arguments.callee);
		});
	} else if (sys.ie && sys.ie < 9){
		var timer = null;
		timer = setInterval(function () {
			try {
				document.documentElement.doScroll('left');
				doReady();
			} catch (e) {};
		}, 1);
	}
}

//跨浏览器添加事件绑定
function addEvent(obj, type, fn) {
	if (typeof obj.addEventListener != 'undefined') {
		obj.addEventListener(type, fn, false);
	} else {
		//创建一个存放事件的哈希表(散列表)
		if (!obj.events) obj.events = {};
		//第一次执行时执行
		if (!obj.events[type]) {	
			//创建一个存放事件处理函数的数组
			obj.events[type] = [];
			//把第一次的事件处理函数先储存到第一个位置上
			if (obj['on' + type]) obj.events[type][0] = fn;
		} else {
			//同一个注册函数进行屏蔽，不添加到计数器中
			if (addEvent.equal(obj.events[type], fn)) return false;
		}
		//从第二次开始我们用事件计数器来存储
		obj.events[type][addEvent.ID++] = fn;
		//执行事件处理函数
		obj['on' + type] = addEvent.exec;
	}
}

//为每个事件分配一个计数器
addEvent.ID = 1;

//执行事件处理函数
addEvent.exec = function (event) {
	var e = event || addEvent.fixEvent(window.event);
	var es = this.events[e.type];
	for (var i in es) {
		es[i].call(this, e);
	}
};

//同一个注册函数进行屏蔽
addEvent.equal = function (es, fn) {
	for (var i in es) {
		if (es[i] == fn) return true;
	}
	return false;
}

//把IE常用的Event对象配对到W3C中去
addEvent.fixEvent = function (event) {
	event.preventDefault = addEvent.fixEvent.preventDefault;
	event.stopPropagation = addEvent.fixEvent.stopPropagation;
	event.target = event.srcElement;
	return event;
};

//IE阻止默认行为
addEvent.fixEvent.preventDefault = function () {
	this.returnValue = false;
};

//IE取消冒泡
addEvent.fixEvent.stopPropagation = function () {
	this.cancelBubble = true;
};


//跨浏览器删除事件
function removeEvent(obj, type, fn) {
	if (typeof obj.removeEventListener != 'undefined') {
		obj.removeEventListener(type, fn, false);
	} else {
		if (obj.events) {
			for (var i in obj.events[type]) {
				if (obj.events[type][i] == fn) {
					delete obj.events[type][i];
				}
			}
		}
	}
}


//跨浏览器获取视口大小
function getInner() {
	if (typeof window.innerWidth != 'undefined') {
		return {
			width : window.innerWidth,
			height : window.innerHeight
		}
	} else {
		return {
			width : document.documentElement.clientWidth,
			height : document.documentElement.clientHeight
		}
	}
}

//跨浏览器获取滚动条位置
function getScroll() {
	return {
		top : document.documentElement.scrollTop || document.body.scrollTop,
		left : document.documentElement.scrollLeft || document.body.scrollLeft
	}
}


//跨浏览器获取Style
function getStyle(element, attr) {
	var value;
	if (typeof window.getComputedStyle != 'undefined') {//W3C
		value = window.getComputedStyle(element, null)[attr];
	} else if (typeof element.currentStyle != 'undeinfed') {//IE
		value = element.currentStyle[attr];
	}
	return value;
}


//判断class是否存在
function hasClass(element, className) {
	return element.className.match(new RegExp('(\\s|^)' +className +'(\\s|$)'));
}


//跨浏览器添加link规则
function insertRule(sheet, selectorText, cssText, position) {
	if (typeof sheet.insertRule != 'undefined') {//W3C
		sheet.insertRule(selectorText + '{' + cssText + '}', position);
	} else if (typeof sheet.addRule != 'undefined') {//IE
		sheet.addRule(selectorText, cssText, position);
	}
}

//跨浏览器移出link规则
function deleteRule(sheet, index) {
	if (typeof sheet.deleteRule != 'undefined') {//W3C
		sheet.deleteRule(index);
	} else if (typeof sheet.removeRule != 'undefined') {//IE
		sheet.removeRule(index);
	}
}

//跨浏览器获取innerText
function getInnerText(element) {
	return (typeof element.textContent == 'string') ? element.textContent : element.innerText;
}

//跨浏览器设置innerText
function setInnerText(elememt, text) {
	if (typeof element.textContent == 'string') {
		element.textContent = text;
	} else {
		element.innerText = text;
	}
}

//获取某一个元素到最外层顶点的位置
function offsetTop(element) {
	var top = element.offsetTop;
	var parent = element.offsetParent;
	while (parent != null) {
		top += parent.offsetTop;
		parent = parent.offsetParent;
	}
	return top;
}

//删除左后空格
function trim(str) {
	return str.replace(/(^\s*)|(\s*$)/g, '');
}

//某一个值是否存在某一个数组中
function inArray(array, value) {
	for (var i in array) {
		if (array[i] === value) return true;
	}
	return false;
}

//获取某一个节点的上一个节点的索引
function prevIndex(current, parent) {
	var length = parent.children.length;
	if (current == 0) return length - 1;
	return parseInt(current) - 1;
}

//获取某一个节点的下一个节点的索引
function nextIndex(current, parent) {
	var length = parent.children.length;
	if (current == length - 1) return 0;
	return parseInt(current) + 1;
}

//阻止默认行为
function predef(e) {
	e.preventDefault();
}