<%init>
my $log_in_status = My::App->authenitcate_user($r);

if ($log_in_status eq 'OK') {
    $m->call_next; # proceeed to /auth_required/foo.html
} 
else {
    my $message = $m->comp('/get_message', key => $log_in_status);
    $m->comp('/non_auth', message => $message);
}
</%init>