totalize method
Totalize order amounts and items
@return
Implementation
Order totalize() {
if (content != null && content!.isNotEmpty) {
amount = 0.00;
tax_amount = 0.00;
for (Item item in content!) {
item.totalize();
amount = amount! + item.total;
tax_amount = tax_amount! + (item.tax * item.qty);
}
}
return this;
}