sub edit_book : Local : Args(1) {
    my ( $self, $c, $id ) = @_;

    my $book = $c->model('DB::Book')->find($id);

    return $self->form($c, $book);
}

sub form : Private {
    my ( $self, $c, $book ) = @_;

    my $form = MyApp::Form::Book->new;

    $c->stash(
        template => 'admin/edit_book.tt',
        title    => 'Edit Book',
        form     => $form,
    );

    $form->process->( item => $book, params => $c->req->params );
    return unless $form->validated;
}