When invoking a JavaScript method, the context variable 'this' is lost

I have developed a basic pointer to a method like this:

export class SmbwaService {
    getExistingArsByLab(labId: number): Observable<SmwbaAr[]> {
        this.otherMethod();
    }

    otherMethod(): void {
    }
}


let method: (x: number) => Observable<SmbwaAr[]>;
method = this.service.getExistingArsByLab;
method(12);

It runs smoothly in terms of calling the getExistingArsByLab method. However, I encounter an error when it attempts to call otherMethod because:

Cannot read property otherMethod of undefined.

What is the correct way to handle this? In my actual code, method is assigned to different methods based on certain conditions.

Answer №1

To create a function reference that is tied to a specific value of this, you can use the Function.bind method:

customMethod = this.service.getExistingArsByLab.bind(this.service)
customMethod(2)

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