אנגולר reactive forms | איך לבדוק שדות עם ולידציה בלחיצה על submit

@Component({
  selector: 'app-general-reactive-form',
  templateUrl: './general-reactive-form.component.html',
  styleUrls: ['./general-reactive-form.component.scss'],
  animations: [inputInAnimation]
})


export class GeneralReactiveFormComponent implements OnInit {
public form: FormGroup;
  
  
  constructor(private fb: FormBuilder) { }
    
  
  public ngOnInit(): void {
    this.form = this.fb.group({
      fullName: ['', Validators.required],
      mail: ['', [Validators.required, Validators.email]],
      phone: ['', Validators.pattern('[0-9]{7,20}')],
      message: ['', Validators.required],
    })
  }
  
  public onSubmit(): void {
  if (this.form.valid) {
  	console.log('form is valid);
  }else {
        Object.keys(this.form.controls).forEach((field: string) => {
        const control: AbstractControl = this.form.get(field);
        control.markAsTouched({ onlySelf: true });
      });    
	}
  }
  
}