html5 localStorage

来自https://developer.mozilla.org/en-US/docs/DOM/Storage

从IE8+,到目前标准浏览器都支持window.localStorage对象,并且一般也都支持window.JSON,这样很好, 因为localStorage存的都是字符串,如果是json格式,刚好很方便用JSON对象处理。

localStorage API如下:

interface Storage {
  readonly attribute unsigned long length;
  [IndexGetter] DOMString key(in unsigned long index);
  [NameGetter] DOMString getItem(in DOMString key);
  [NameSetter] void setItem(in DOMString key, in DOMString data);
  [NameDeleter] void removeItem(in DOMString key);
  void clear();
};

同时一个localStorage变量storage也支持属性直接读写,比如:

storage.a = 'a';
storage['b'] = 'b';

不支持localStorage的浏览器,可以用cookie来兼容一下,当然cookie存储大小上限一般是4K,兼容如下:

if (!window.localStorage) {
  window.localStorage = {
    getItem: function (sKey) {
      if (!sKey || !this.hasOwnProperty(sKey)) { return null; }
      return unescape(document.cookie.replace(new RegExp("(?:^|.*;\\s*)" + escape(sKey).replace(/[\-\.\+\*]/g, "\\$&") + "\\s*\\=\\s*((?:[^;](?!;))*[^;]?).*"), "$1"));
    },
    key: function (nKeyId) {
      return unescape(document.cookie.replace(/\s*\=(?:.(?!;))*$/, "").split(/\s*\=(?:[^;](?!;))*[^;]?;\s*/)[nKeyId]);
    },
    setItem: function (sKey, sValue) {
      if(!sKey) { return; }
      document.cookie = escape(sKey) + "=" + escape(sValue) + "; expires=Tue, 19 Jan 2038 03:14:07 GMT; path=/";
      this.length = document.cookie.match(/\=/g).length;
    },
    length: 0,
    removeItem: function (sKey) {
      if (!sKey || !this.hasOwnProperty(sKey)) { return; }
      document.cookie = escape(sKey) + "=; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/";
      this.length--;
    },
    hasOwnProperty: function (sKey) {
      return (new RegExp("(?:^|;\\s*)" + escape(sKey).replace(/[\-\.\+\*]/g, "\\$&") + "\\s*\\=")).test(document.cookie);
    }
  };
  window.localStorage.length = (document.cookie.match(/\=/g) || window.localStorage).length;
}

跟localStorage一样的,还有个sessionStorage,顾名思义就是数据存储有效期等于session的有效期。

更多了解见这里: http://www.cnblogs.com/xiaowei0705/archive/2011/04/19/2021372.html

http://cssor.com/html5-localstorage.html

参与评论

电子邮件地址不会被公开。 必填项已用*标注

*

全部分类
Books(4)code(7)database(6)html&css(24)java(11)JavaScript(48)jQuery(24)linux(20)python(1)React(1)share(1)soft(4)solution(53)thinking(17)vim(9)WordPress(8)前端优化(12)拓展(33)服务器(31)移动开发(4)自然(22)