利用jsonp實現跨域登錄

<script type="text/javascript" src="js/jquery-1.9.1.js"></script>
<script>
	$(function(){
		$.ajax({
			url:'http://www.xxx.com/users/syncLogin',
			type:"GET",
			dataType:"jsonp",
			jsonp:'callback',
			success:function(data){
				document.cookie="ECS_ID="+data.id;
				alert(data.id);
			}
		});
	});
</script>

public function syncLogin(){
	$this->autoRender = false;
	$callback=$_GET['callback'];
	echo $callback.'('.json_encode(array('id'=>$_COOKIE[ECS_ID])).')';
}

第二版：初版cookie改變後須要刷新才生效

$.ajax({
	url:'http://www.xxx.com/users/syncLogin',
	type:"GET",
	dataType:"jsonp",
	jsonp:'callback',
	success:function(data){
		var cookie_str=document.cookie;
		var date=new Date();
		date.setTime(date.getTime()+365*24*3600*1000);
		document.cookie="ECS_ID="+data.id+";expires="+date.toGMTString();
		cookie_str=cookie_str.replace(/; /g,';');
		var cookie_array=cookie_str.split(';');
		for(var i=0,len=cookie_array.length;i<len;i++){
			if(cookie_array[i].split('=')[0]=='ECS_ID'){
				if(cookie_array[i].split('=')[1]!=data.id+''){
					location.reload(1);
				}
			}
		}
	}
});

第三版：提取function

function setCookie(c_name,value,expiredays)
{
	var exdate=new Date();
	exdate.setDate(exdate.getDate()+expiredays);
	document.cookie=c_name+ "=" +escape(value)+
	((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
}
function getCookie(c_name)
{
	var cookie=document.cookie;
	var cookie_len=document.cookie.length;
	if (cookie_len>0){
	  c_start=cookie.indexOf(c_name + "=")
		if (c_start!=-1){ 
			c_start=c_start + c_name.length+1; 
			c_end=cookie.indexOf(";",c_start);
		    if (c_end==-1){
		    	c_end=cookie_len;
		    }
			return unescape(cookie.substring(c_start,c_end));
		} 
	}
	return "";
}
$.ajax({
	url:'http://www.xxx.com/users/syncLogin',
	type:"GET",
	dataType:"jsonp",
	jsonp:'callback',
	success:function(data){
		var cookie_str=document.cookie;
		var cookie_ecs_id=getCookie('ECS_ID');
		setCookie('ECS_ID',data.id,365);
		if(cookie_ecs_id!=data.id+''){
			location.reload(1);
		}
	}
});