Pass an input value into a ngComponentOutlet created component?

Question

I have a component like:

@Component({
  selector: 'app-item',
  template: '<p>{{title}}</p>'
})
export class TitleComponent {
  @Input() title:string;
}

@Component({
  selector: 'app-foo',
  template: '<ng-container *ngComponentOutlet="outlet"></ng-container>'
})
export class FooComponent {
  outlet = TitleComponent;
}

How do you pass input title value on the ng-container for the TitleComponent or how can I set this value?

Answer 1

As Reno has already mentioned, you can use an injector to inject values.

For the sake of completeness, here is an example with a dynamic "title" value:

export const TITLE = new InjectionToken<string>('app.title'); 


@Component({
  selector: 'app-item',
  template: '<p>{{title}}</p>'
})
export class TitleComponent implements OnInit {
  @Input() title:string;

  constructor(@Inject(TITLE) private titleInjected: string){

  } 

  ngOnInit() {
    this.title = this.title || this.titleInjected;
  }

}


@Component({
  selector: 'app-foo',
  template: '<ng-container *ngComponentOutlet="outlet; injector: myInjector"></ng-container>'
})
export class FooComponent {
  outlet = TitleComponent;
  myInjector: Injector;

  constructor(injector: Injector){
    let title = 'My dynamic title works!';
    this.myInjector = ReflectiveInjector.resolveAndCreate([{ provide: TITLE, useValue: title }], injector);
  }
}


@NgModule({
  providers: [
    { provide: TITLE, useValue: '' }
  ]
})
export class AppModule { }

Answer 2

An example solution is shown in the ngComponentOutlet documentation, specifically the second example with the @Injectable, as titusfx also mentioned.

Here is what it would look like with your use case:

@Injectable()
class Info {
  title = 'a little hacky';
}

@Component({
  selector: 'app-item',
  template: '<p>{{info.title}}</p>'
})
export class TitleComponent {
  // @Input() title:string;
  constructor(public info: Info){ }
}

@Component({
  selector: 'app-foo',
  template: '<ng-container *ngComponentOutlet="outlet; injector: myInjector"></ng-container>'
})
export class FooComponent {
  outlet = TitleComponent;
  myInjector: Injector;
  constructor(injector: Injector){
    this.myInjector = ReflectiveInjector.resolveAndCreate([Info], injector);
  }
}

Answer 3

Consider using ng-dynamic-component library to work with dynamic components.