What we want

lots of storage
on the client’s side
lasting beyond a page refresh
isnt transmitted to the server

http request containing sensitive data in cookies are transmitted unencrypted over the internet

During the first great browser wars

microsoft invented many things
of our concern is the internet explorer and DHTML Behaviors

- userData is our focus

Flash cookies was invented in 2002 that Local Shared Objects was in

local shared object allowed Flash to store up to 100 KB of data per domain.

HTML 5 Storage

this saves the day

function supports_html5_storage() {
  try {
    return 'localStorage' in window && window['localStorage'] !== null;
  } catch (e) {
    return false;
  }
}

HTML5 storage is based on named key/value pairs.

Store data on a named key
retreive data with same key

interface Storage {
  getter any getItem(in DOMString key);
  setter creator void setItem(in DOMString key, in any data);
};

var foo = localStorage.getItem("bar");
// ...
localStorage.setItem("bar", foo);

var foo = localStorage["bar"];
// ...
localStorage["bar"] = foo;

interface Storage {
  deleter void removeItem(in DOMString key);
  void clear();
};

interface Storage {
  readonly attribute unsigned long length;
  getter DOMString key(in unsigned long index);
};