Question

its good practice to pass value object to entity methods (in terms of DDD)?
For example I have a method in my entity Customer:

SetAddress(Address invoiceAddress); 

is it valid? Or I should pass address parameters as

SetAddress(string street, string town, string zip, string country);

and let the customer handle the creation of address object and if needs throw an exception.

Address is immutable object.

Answer 1

You should definitely pass an Address object. It is valid in terms for DDD and it’s also good for extensibility (i.e. you can add more fields to Address object without changing the signature of the SetAddress method).

Also the Address object should contain validation logic for address information, which a Customer.SetAddress(...) method can execute before setting the address:

public class Customer
{
    public SetAddress(Address invoiceAddress)
    {
        // ToDo: Execute validation logic encapsulated in 'Address' object
        // ToDo: Execute additional validation logic here
    }
}