Maintaining State

State

• HTTP sessions are stateless
• HTTP sessions only last from browser request to server reply
• To manage things like shopping carts, session info needs to be kept or restored

Cookies

• Cookies are identifiers with no particular meaning
• They are delivered from servers to clients
• The client stores them for a period of time
• On each request to that same server, the cookie is included in the request
• The server can use this cookie to restore state it collected earlier, indexed by this cookie

Hidden Fields

• A field in an HTML Form may be labelled as "hidden"
• This will nto show in the form
• The value of the field will be set by the server
• When the form is submitted, it will be returned to the server
• State information can be placed in these fields
• For privacy, this should not contain personal information