paulb@654 | 1 | <?xml version="1.0" encoding="iso-8859-1"?> |
paulb@358 | 2 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
paulb@358 | 3 | <html xmlns="http://www.w3.org/1999/xhtml"> |
paulb@358 | 4 | <head> |
paulb@358 | 5 | <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type" /> |
paulb@358 | 6 | <title>Cookies, Sessions, Users and Persistent Information</title> |
paulb@358 | 7 | <link href="styles.css" rel="stylesheet" type="text/css" /> |
paulb@358 | 8 | </head> |
paulb@358 | 9 | <body> |
paulb@358 | 10 | <h1>Cookies, Sessions, Users and Persistent Information</h1> |
paulb@358 | 11 | <p>Due to the nature of the communications mechanisms |
paulb@654 | 12 | involved, Web applications do not have automatic or "magic" |
paulb@358 | 13 | knowledge about the people or entities accessing them as application |
paulb@358 | 14 | users. Moreover, Web applications do not necessarily remember anything |
paulb@358 | 15 | about what that user has done before. Due to this behaviour, where |
paulb@358 | 16 | every request must tell the application as much as possible for an |
paulb@358 | 17 | operation to be carried out, Web applications are referred to as being |
paulb@358 | 18 | "stateless".</p> |
paulb@358 | 19 | <p>Yet there are a number of ways of maintaining "state" information - |
paulb@358 | 20 | that is, to remember the following things:</p> |
paulb@358 | 21 | <ul> |
paulb@358 | 22 | <li>Some kind of identify for the user, if only to be able to say |
paulb@358 | 23 | that such a user has visited before (if not to actually give them a |
paulb@358 | 24 | name).</li> |
paulb@358 | 25 | <li>Some details about their previous interactions with the |
paulb@358 | 26 | application.</li> |
paulb@358 | 27 | </ul> |
paulb@358 | 28 | <p>Such state information is typically provided using a number of |
paulb@358 | 29 | different mechanisms:</p> |
paulb@358 | 30 | <ul> |
paulb@358 | 31 | <li><a href="cookies.html">Cookies</a></li> |
paulb@358 | 32 | <li><a href="sessions.html">Sessions and Persistent Information</a></li> |
paulb@358 | 33 | <li><a href="users.html">Users and Authentication</a></li> |
paulb@358 | 34 | </ul> |
paulb@358 | 35 | </body> |
paulb@358 | 36 | </html> |