Choose the best storage place available

storageSwitcher.js

/**
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <gecko@dvp.io> wrote this file. As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return Antoine "Gecko" Pous
 */

    // See https://gist.github.com/Antoine-Pous/d0a597ca756b5411ebd2
var cookieChecker = function(){return"undefined"!=typeof navigator.cookieEnabled?(document.cookie="ac=test",e=-1!=document.cookie.indexOf("ac")?!0:!1,document.cookie="ac=; expires=Thu, 01 Jan 1970 00:00:00 UTC",e):navigator.cookieEnabled},
    // See https://gist.github.com/Antoine-Pous/c73e5a3a3b1e9507597d
    LSChecker = function(){try{return localStorage.setItem("test","test"),localStorage.removeItem("test"),!0}catch(t){return!1}},
    // Storage status
    canStore;

if(canStore = LSChecker()) {
  var configRead = function(name) {
    return JSON.parse(localStorage.getItem(name));
  }, configWrite = function(name, data) {
    return localStorage.setItem(name, JSON.stringify(data));
  }, configRemove = function(name) {
    return localStorage.removeItem(name);
  }
} else if(canStore = cookieChecker()) {
  var configRead = function(name) { 
    return AC_config.name; 
  }, configWrite = function(name, data) {
    var d = new Date();
    d.setTime(d.getTime() + (365*24*60*60*1000)); 
    return document.cookie = name + "=" + JSON.stringify(data) + "; expires=" + d.toUTCString();
  }, configRemove = function(name) {
    return document.cookie = name + "=; expires=Thu, 01 Jan 1970 00:00:00 UTC"; 
  }
}

// We now store data in localstorage if available, or in cookies if localstorage is not available
// If both localstorage and cookies are not available no data can be stored
if(canStore) {
  configWrite('auth', {login: 'Gecko', hash: 'sha256'});
}