(Polymorphism) Addition parameter pass to constructor of derived class in factory pattern - oop

Question

In factory pattern, we use a Factory class to produce a Product class that implement Abstract Product.
interface AbstractProduct {
public string getDetail();
}
class Product_A : AbstractProduct {
public string getDetail();
}
class Product_B : AbstractProduct {
public string getDetail();
}
class Factory {
public AbstractProduct produce(int product_id){
if (product_id == 1){
return Product_A();
}
else if (product_id == 2){
return Product_B();
}
}
}
int main() {
Factory factory = new Factory();
int id; // a random number either 1 or 2
print(factory.produce(id).getDetail());
}
My question is, what if today we need extract information to pass into Product_B from main(), for example a reference of a class instance.
int main() {
// object that need to be passed into Product_B
Database database = new Database();
Factory factory = new Factory();
int id; // a random number either 1 or 2
print(factory.produce(id).getDetail());
}
class Product_B : AbstractProduct {
public string getDetail() {
// I need the reference of database here.
// I'm unable to instance a database in side Product_B.
// I need to somehow pass it into Product_B.
database.query();
}
}
The only solution come to my mind is...
class Factory {
// pass the reference here
public AbstractProduct produce(int product_id, Database db){
if (product_id == 1){
return Product_A();
}
else if (product_id == 2){
return Product_B(db);
}
}
}
Is there any good solution or relative design pattern can solve this problem Elegant and Clean ? Thanks a lot.

Answer 1

The downside with your solution is that, every client of the Factory must have a Database in order to call the produce method.
So you can use the Abstract Factory pattern here:
interface AbstractFactory {
AbstractProduct produce();
}
class Factory_A implements AbstractFactory {
AbstractProduct produce() { return new Product_A(); }
}
class Factory_B implements AbstractFactory {
private Database db;
public Factory_B(Database db) { this.db = db; }
AbstractProduct produce() { return new Product_B(db); }
}
class Client {
private AbstractFactory factory;
public Client(AbstractFactory factory) { this.factory = factory; }
public void foo() {
AbstractProduct product = factory.produce();
// ...
}
}
void main() {
AbstractFactory factory = random() == 1 ?
new Factory_A() :
new Factory_B(new Database(...));
print(factory.produce().getDetail());
Client client = new Client(factory);
client.foo();
}
Hope this helps.