Angular 2 dynamic dependency injection based on @Input()

Question

Suppose I have an Angular 2 component-directive, where I want the injected dependency that the component uses to be determined by an @Input().

I want to write someth

Answer 1

It is

// can be a service also for overriding and testing
export const trendyServiceMap = {
  serviceA: ServiceA,
  serviceB: ServiceB
}

constructor(private injector: Injector) {}    
...
ngOnInit() {
    if (trendyServiceMap.hasOwnProperty(this.use)) {
        this.service = this.injector.get(trendyServiceMap[this.use]);
    } else {
        throw new Error(`There's no such thing as '${this.use}'`);
    }
}