_history : { //缓存
isLocalStorage:window.localStorage?true:false,
set : function(key,value){ //设置缓存
if(this.isLocalStorage){
window.localStorage.setItem(key,value);
}else{
var expireDays = 365; //失效时间
var exDate=new Date();
exDate.setTime(exDate.getTime()+expireDays*24*60*60*1000);
document.cookie=key + "=" + escape(value)+";expires=" + exDate.toGMTString();
}
},
read : function(key){ //读取缓存
if(this.isLocalStorage){
return window.localStorage.getItem(key);
}else{
var arr,reg=new RegExp("(^| )"+key+"=([^;]*)(;|$)");
if(arr=document.cookie.match(reg)){
return unescape(arr[2]);
}else{
return null;
}
}
},
del : function(key){ //删除缓存
if(this.isLocalStorage){
localStorage.removeItem(key);
}else{
var exDate = new Date();
exDate.setTime(exDate.getTime() - 1);
var read_val=this.read(key);
if(read_val!=null) document.cookie= key + "="+read_val+";expires="+exDate.toGMTString();
}
}
},
缓存下用户操作 如果用户点击过”往返“我就缓存它 刷新或者下次打开就是往返
localStorage+cookie