CODEWITHSUNDEEP
angularjsscopetypescripttypescript1.6abstract-methods
Luka
Luka

Reputation: 4211

Typescript 1.6 abstract methods

I want to do this:

export abstract class Base{
    constructor(){
       this.activate();
    }

    protected abstract activate():void;
}

class MyClass extends Base{
    static $inject = ['myService'];
    constructor(service: myService){
        super();
        this.myService = myService;
    }
    activate():void{
        this.myService.doSomething();
    }
}

But I can't because type of 'this' in derived class method is of 'Base'. How can i make my code work?

Please help. Thanks

Upvotes: 0

Views: 861

Answers (1)

huysentruitw
huysentruitw

Reputation: 28141

The problem is that, the moment activate() gets called, this.myService is not yet set.

This is the callstack:

MyClass::constructor() -> super() -> Base::constructor() -> MyClass::activate()

So in the constructor of MyClass, you'll need to assign this.myService before calling the base constructor:

class MyClass extends Base{
    static $inject = ['myService'];
    constructor(service: myService){
        this.myService = myService; // <-- before super();
        super();
    }
    activate():void{
        this.myService.doSomething();
    }
}

Upvotes: 3

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