www/cookies.yaws

<erl>
out(A) -> 
       {ssi, "TAB.inc", "%%",[{"cookies", "choosen"}]}.
</erl>

<div id="entry">


  <h1>Yaws and Cookies</h1>
  <p>
    Cookies are the means in HTTP to assign data to a session. A HTTP session
    typically consists of many (and sometimes concurrent) TCP connections from the
    client to the web server. The first time a client arrives to our webserver, we
    issue the HTTP header <tt>Set-Cookie: var=someval</tt>. The browser will then in 
    subsequent connections to the same server pass this cookie "var=someval" in its
    client side <tt>Cookie: var=someval</tt> header. We can thereby assign state to a
    session, either through data actualy encoded into the cookie value itself, or by
    associating server side session data to the cookie.</p>
  <p>

    Let's do an example where we set a simple cookie, and create a specific erlang process
    which is then responsible for that session. 
    The cookie value will be a string encoding of the pid handling the session.
  </p>
  <p>
    The yaws code in 
    <a href="setcookie.yaws">setcookie.yaws</a> sets the cookie in the browser.</p>

  <p>And the yaws code in <a href="readcookie.yaws">readcookie.yaws</a> 
    will read the cookie
    and report some uninteresting session data.
  </p>

  <p>
    A correct definition of cookies can be found at Netscapes 
    <a href="http://www.netscape.com/newsref/std/cookie_spec.html">cookie spec</a></p>


  <p>The code to set the cookie looks like:</p>

<erl>
out(A) ->
       {ok, B} = file:read_file(A#arg.docroot ++ "/setcookie.yaws"),
       {ehtml,
        {'div', [{class, "box"}],
        {pre,[], B}}}.

</erl>


</div>


<erl>
out(A) -> {ssi, "END2",[],[]}.
</erl>