HKOBA / YATT-Lite-0.121 / samples / sess_backed / 3 / html / session.yatt 
<!yatt:args dump="value/1">

<yatt:layout>
<h2>Session3 test1</h2>
&yatt:session_start();

<yatt:if "&yatt:dump;">
<pre id="session_content">session content=&yatt:psgix_session();</pre>
</yatt:if>

<form method="POST">
  <dl>
  <yatt:foreach my=name list="qw/foo bar baz/">
    <dt>&yatt:name;</dt>
    <dd><input name=".&yatt:name;" value="&yatt:psgix_session(){:name};"></dd>
  </yatt:foreach>
  </dl>
  <input type="submit" name="!set">
</form>
</yatt:layout>

<!yatt:action set>
  
$this->entity_session_start;

my $env = $CON->env->{'psgix.session'};

foreach my $name (qw/foo bar baz/) {
  $env->{$name} = $CON->param(".".$name);
}

$CON->redirect($CON->mkurl);

<!yatt:widget layout>
<!doctype html>
<html>
<meta charset="utf-8">
<body>
<yatt:body/>
</body>
</html>