工厂模式在JS中的实践

/**

  * Storage Factory -Author 吴双 cnblogs.com/tdws

  */

 StorageUtilManager:newObject({

  createStorageUtil:function() {

   if(window.applicationCache) {

    returnAppUtil.LocalStorageUtil;

   }else{

    returnAppUtil.CookieStorageUtil;

   }

  }

 }),

 /**

  * implement Storage -Author 吴双

  * write()

  * get()

  */

 CookieStorageUtil: {

  write:function(key, dataObj) {

   this._clearCookie(key);

   //写入的字符串

   vardataObjStr = JSON.stringify(dataObj);

   this._setCookie(key, dataObjStr, 15);

  },

  get:function(key) {

   returnthis._getCookie(key);

  },

  _setCookie:function(cname, cvalue, exdays) {

   vard =newDate();

   d.setTime(d.getTime() + (exdays * 24 * 60 * 60 * 1000));

   varexpires ="expires="+ d.toUTCString();

   varpath ="path=/";

   document.cookie = cname +"="+ cvalue +"; "+ expires +"; "+ path;

  },

  _getCookie:function(cname) {

   varname = cname +"=";

   varca = document.cookie.split('');

   for(vari = 0; i < ca.length; i++) {

    varc = ca[i];

    while(c.charAt(0) ==' ') c = c.substring(1);

    if(c.indexOf(name) != -1)returnc.substring(name.length, c.length);

   }

   returnnull;

  },

  _clearCookie:function(key) {

   this._setCookie(key,"", -1);

  }

 },

 /**

  * implement Storage cnblogs.com/tdws

  * write()

  * get()

  */

 LocalStorageUtil: {

  write:function(key, dataObj) {

   this._writeLocalStorage(key, dataObj);

  },

  get:function(key) {

   returnthis._getFromLocalStorage(key);

  },

  _writeLocalStorage:function(key, dataObj) {

   varlocalStorage = window.localStorage;

   localStorage.removeItem(key);

   //对象转化为字符串,将objStr按正常的方式存入localStorage中

   vardataObjStr = JSON.stringify(dataObj);

   localStorage.setItem(key, dataObjStr);

  },

  _getFromLocalStorage:function(key) {

   varlocalStorage = window.localStorage;

   returnlocalStorage.getItem(key);

  },

  _removeLocalStorage:function(key) {

   varlocalStorage = window.localStorage;

   localStorage.removeItem(key);

  }

 }