bot-detail-header.ts

@Component({
    selector: 'bot-detail-header',
    template: `
    <h2>{{bot?.description}}</h2>
    <h5>Total completed Rescues: {{completedRescues?.length}}</h5>
    <newsletter [firstName]="firstName" (subscribe)="onSubscribe($event)"></newsletter>
`, 
  changeDetection: ChangeDetectionStrategy.OnPush
})
export class BotDetailHeaderComponent {
    @Input() bot: Bot;
    @Input() completedRescues: CompletedRescue[];
    @Input() firstName:string;
    @Output() subscribe = new EventEmitter();

    onSubscribe(email:string) {
        this.subscribe.emit(email);
    }
}