- SendEmail method of Emailer class
- SendNotification method of Mobile class
These types of classes/methods, they have something in common:
- They all need to send some information
- Or you can say they all need to update some information
Now I have re-designed the class structrue:
- BankAccount (now depends on IAccountObserve)
- IAccountObserver
- Emailer
- Mobile
public class BankAccount
{
IAccountObserver emailer; //loose coupling
public void Withdraw(int data)
{
//...
UserAccountArgs args = new UserAccountArgs();
//...
emailer.Update(args);
}
}
public interface IAccountObserver
{
void Update(UserAccountArgs args);
}
public class Emailer : IAccountObserver
{
public void Update(UserAccountArgs args)
{
//...
string toAddress = args.ToAddress;
}
}
public class Mobile : IAccountObserver
{
public void Update(UserAccountArgs args)
{
//...
string mobileNumber = args.MobileNumber;
}
}
This code resolve the tight coupling problems, so the BankAccount doesn't need to be changed in order to cater for any future modification. But it only illustrates an one-to-one relationship between BankAccount class and Emailer class, the next session will explain how to implement one-to-many relationships.
