sub update {
    my %args  = @_;

    my @messages = ();
    my @errors   = validate_args( %args );

    if (@errors) {

        # package the errors up as error messages
        @messages = map {{ class => 'error', data => $_ }} @errors;

        # override landing page back to update so user can fix errors
        # $comp is set to 'list' prior to this method call
        $comp = 'update';

    } else {

        my $sth = $dbh->prepare('
            UPDATE thingy SET
                foo = ?,
                bar  = ?
            WHERE id = 1
        ');

        $sth->execute(
            $args{foo},
            $args{bar},
        );

        push( @messages, {
            class => 'message',
            data => 'Thingy successfully updated.'
         } );
    }

    return @messages;
}