require SL::DB::PriceFactor;
require SL::DB::Unit;
- SL::DB::Part->load_cached(map { $_->parts_id } @{ $self->items });
+ SL::DB::Part->load_cached(map { $_->parts_id } @{ $self->items }) if @{ $self->items };
my %units_by_name = map { ( $_->name => $_ ) } @{ SL::DB::Manager::Unit->get_all };
my %price_factors_by_id = map { ( $_->id => $_ ) } @{ SL::DB::Manager::PriceFactor->get_all };