import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';

@Component({
  selector: 'app-demo',
  template: `
    <form [formGroup]="form">
      <input type="text" formControlName="yourname">
      <app-stars formControlName="stars"></app-stars>
    </form>
    
    <pre>
      {{form.valid}}
      {{form.touched}}
      {{form.get('stars').errors | json}}
    </pre>
  `
})
export class DemoComponent implements OnInit {
  form: FormGroup;

  constructor(private fb: FormBuilder) {
    this.form = fb.group({
      yourname: ['', Validators.required],
      stars: [null, Validators.required]
    });

  }

  ngOnInit() {
  }

}