How to reference helper methods methods using 'this' from an Injectable?

Question

An Injectable Class's 'this' is referencing the injected component's this.

Wanted to use injectable to abstract code from the component. But when I use 'this' to reference other methods in a parent method in the @Injectable class and then try to use that component that it is injected.

The method thas is called as this.enclosedMethod does not work. Error: this.enclosedMethod is not a function. Logging the 'this' shows that it referencing the Component class that's been injected. For example

@Injectable()
export class UploaderService {

constuctor() {}

    parentMethod() {
        this.logSomething();
        const that = this;
        that.logSomething();
    }

    logSomething() {
        console.log('Testing');
    }

}


@Component()
export class AppComponent implements OnInit {

    constructor(private upload: UploaderService) {
        this.parentMethod = upload.parentMethod;
    }

    NgOnInit(): void {
       this.parentMethod(); // this.logSomething is not a function or that.logSomething is not a function 
    }

}

Question: how do you use methods in other methods in an Injectable? I am drawing a blank at the moment

score 0 · Accepted Answer · answered Oct 06 '17 at 05:23

how do you use methods in other methods in an Injectable? I am drawing a blank at the moment

Fix

Fix your this :

@Component()
export class AppComponent implements OnInit {

    constructor(private upload: UploaderService) {
        this.parentMethod = () => upload.parentMethod(); // FIXED!
    }

    NgOnInit(): void {
       this.parentMethod(); 
    }

}

More

Some docs https://basarat.gitbooks.io/typescript/docs/arrow-functions.html

How to reference helper methods methods using 'this' from an Injectable?

1 Answers1

Fix

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