cookie.js

// by Jason McCreary October 10, 2008
// http://jason.pureconcepts.net/2008/10/javascript_cookie_object/

var Cookie = {
  data: {},
  options: {expires: 1, domain: "", path: "", secure: false},

  init: function(options, data) {
    Cookie.options = Object.extend(Cookie.options, options || {});
  
    var payload = Cookie.retrieve();
      if(payload) {
          Cookie.data = payload.evalJSON();
      }
      else {
          Cookie.data = data || {};
      }
      Cookie.store();
  },
  getData: function(key) {
      return Cookie.data[key];
  },
  setData: function(key, value) {
      Cookie.data[key] = value;
      Cookie.store();
  },
  removeData: function(key) {
      delete Cookie.data[key];
      Cookie.store();
  },
  retrieve: function() {
      var start = document.cookie.indexOf(Cookie.options.name + "=");

      if(start == -1) {
          return null;
      }
      if(Cookie.options.name != document.cookie.substr(start, Cookie.options.name.length)) {
          return null;
      }

      var len = start + Cookie.options.name.length + 1;   
      var end = document.cookie.indexOf(';', len);

      if(end == -1) {
          end = document.cookie.length;
      } 
      return unescape(document.cookie.substring(len, end));
  },
  store: function() {
      var expires = '';

      if (Cookie.options.expires) {
          var today = new Date();
          expires = Cookie.options.expires * 86400000;
          expires = ';expires=' + new Date(today.getTime() + expires);
      }

      document.cookie = Cookie.options.name + '=' + escape(Object.toJSON(Cookie.data)) + Cookie.getOptions() + expires;
  },
  erase: function() {
      document.cookie = Cookie.options.name + '=' + Cookie.getOptions() + ';expires=Thu, 01-Jan-1970 00:00:01 GMT';
  },
  getOptions: function() {
      return (Cookie.options.path ? ';path=' + Cookie.options.path : '') + (Cookie.options.domain ? ';domain=' + Cookie.options.domain : '') + (Cookie.options.secure ? ';secure' : '');      
  }
};