sub register : Path('/user/register') {
    my ($self, $c) = @_;

    my (%params) = &_parseParametersIntoHash($c);

    # --- if no params, assume it's executed for the first time
    unless (scalar keys %params) {
        my %data = ( template     => 'user/register.tmpl',
                     title        => 'Registrierung',
                     message      => '',
                     username     => '',
                     emailaddress => '',
                     );
        while (my ($k, $v) = each %data) { $c->stash->{$k} = $v }

        return;
    } # unless

    # --- else if mandatory parameters are submitted
    my $message = "";
    if( $params{username} =~ /^\s*$/ ) {
        $message .= "<br />Bitte das Feld Benutzername ausf&uuml;llen";
    } # if
    if( $params{emailaddress} =~ /^\s*$/ ) {
        $message .= "<br />Bitte das Feld E-Mai-Adresse ausf&uuml;llen";
    } # if
    if( $params{password} =~ /^\s*$/ or $params{passwordcheck} =~ /^\s*$/) {
        $message .= "<br />Bitte beide Passwort-Felder ausf&uuml;llen";
    } # if
    unless( $params{agreeagb} ) {
        $message .= "<br />Bitte die Bestimmungen akzeptieren";
    } # if

    if ($message) { # if a parameter is missing, prompt for it
        my %data = ( template     => 'user/register.tmpl',
                     title        => 'Registrierung',
                     message      => $message,
                     %params,
                );
        while (my ($k, $v) = each %data) { $c->stash->{$k} = $v }
        return;
    } # if

    # shortcut
    my $registerConf = $c->config->{register};
    
    # --- check if params are valid
    if( length $params{username} < $registerConf->{minUserNameLength} ) {
        $message .= "<br />Der Benutzername mu&szlig; mindestens  "
            . $registerConf->{minUserNameLength} . " Zeichen lang sein";
    } # if
    elsif( length $params{username} > $registerConf->{maxUserNameLength} ) {
        $message .= "<br />Der Benutzername darf h&ouml;chstens  "
            . $registerConf->{maxUserNameLength} . " Zeichen lang sein";
    } # if

    if( $params{password} ne $params{passwordcheck} ) {
        $message .= "<br />die Passw&ouml;rter sind nicht identisch";
    } # if
    elsif( length $params{password} < $registerConf->{minPasswordLength} ) {
        $message .= "<br />Das Passwort mu&szlig; mindestens  "
            . $registerConf->{minPasswordLength} . " Zeichen lang sein";
    } # if
    elsif( length $params{password} > $registerConf->{maxPasswordLength} ) {
        $message .= "<br />Das Passwort darf h&ouml;chstens  "
            . $registerConf->{maxPasswordLength} . " Zeichen lang sein";
    } # if

    unless( Mail::RFC822::Address::valid( $params{emailaddress} ) ) {
        $message .= "<br />E-Mail '$params{emailaddress}' ung&uuml;ltig";
    } # unless

    # check db if username is free
    # send mail
    
    if ($message) { # if a parameter is invalid, prompt for it
        my %data = ( template     => 'user/register.tmpl',
                     title        => 'Registrierung',
                     message      => $message,
                     %params,
                );
        while (my ($k, $v) = each %data) { $c->stash->{$k} = $v }

        return;
    } # if

    # else redirect to register_finished
    my %data = ( template     => 'user/register_finished.tmpl',
                 title        => 'Registrierung',
                 message      => '',
                 %params,
            );
    while (my ($k, $v) = each %data) { $c->stash->{$k} = $v }
} # register