Question

I’m new to using inherited classes, so I may be missing something completly obvious. I have two classes, A and B, that both inherit some other class Z. Class Z has a number of methods etc.

What I’m trying to figure out is how to create an event (or just some method) in class A and B that is triggered after some method in class Z finishes…

Is there a way to do that?

Cheers

Answer 1

Using abstract methods:

Subclasses override abstract method from base class.

abstract class Z {
    abstract doSomethingElse();

    doSomething(){
        //main logic

        doSomethingElse();
    }
}

class A : Z {
    doSomethingElse(){
        //subclass logic
    }
}

class B : Z {
    doSomethingElse(){
        //subclass logic
    }
}

Calling base by convention:

Override virtual methods from base class & invoke base method at the beginning

class Z {
    doSomething(){
        //main logic
    }
}

class A : Z {
    doSomething(){
        base.doSomething()

        //subclass logic
    }
}

class B : Z {
    doSomething(){
        base.doSomething()

        //subclass logic
    }
}

Delegate injection:

Require a delegate in the superclass constructor. Invoke the delegate.

class Z {
    delegate somethingDone

    Z(_somethingDone){
        somethingDone = _somethingDone
    }

    doSomething(){
        //main logic

        somethingDone()
    }
}

class A : Z {
    A() : base(onSomethingDone){

    }

    onSomethingDone(){
        //subclass logic
    }
}

class B : Z {
    B() : base(onSomethingDone){

    }

    onSomethingDone(){
        //subclass logic
    }
}

Event Subscription:

Fire an event when the action happens. Other classes subscribe to the event

class Z {
    doSomething(){
        //main logic

        fireEvent("SomethingDone")
    }
}

class A {
    A(){
        subscribeToEvent("SomethingDone", onSomethingDone)
    }

    onSomethingDone(){
        //subclass logic
    }
}

class B {
    B(){
        subscribeToEvent("SomethingDone", onSomethingDone)
    }

    onSomethingDone(){
        //subclass logic
    }
}