如何在角度5中使用ngoninit在前端中设置日期值

Question

i have an <input type="date"> which i want to be filled when the user enters the route. By visiting the site the input field should already be the actual date. So i think ngOnInit() should be what i need. But what do i have to do to have the actual date filled in as a value to the input field, when the user enters the route?

I already tried to achive this by searching the web but only found some old solutions for angularjs although i'm using angular 5 which is not compareable with angularjs. The postings i found all pointed to the scope which is no longer existent.

The Documentation for ngOnInit also does not help me :/

HTML

<div class="form-group">
    <label>Eingangsdatum</label>
    <input type="date" [(ngModel)]="dateArrival" id="dateArrivalPicker" value="" name="dateArrival" class="form-control">
</div>

Compontent

@Component({
  selector: 'app-terminals-create',
  templateUrl: './terminals-create.component.html',
  styleUrls: ['./terminals-create.component.css']
})
export class TerminalsCreateComponent implements OnInit {

  type: String;
  serial: String;
  layout: String;
  dateArrival: Date;
  activated: Boolean;
  setup: String;
  firmware: String;
  installedAt: String;
  createdBy: String;
  createdDate: Date;
  lastModified: Date;
  lastModifiedBy: String;
  notes: String;
  macAddress: String;


  constructor(
    private validateService: ValidateService,
    private flashMessage: FlashMessagesService,
    private authService: AuthService,
    private router: Router
  ) { }

  ngOnInit() {}

}

---

If i do like briosheje wrote in his comments it works, his answer doesn't :/. And there is one more thing... by using his comment i get two big errors inside my console:

Error: If ngModel is used within a form tag, either the name attribute must be set or the form
      control must be defined as 'standalone' in ngModelOptions.

      Example 1: <input [(ngModel)]="person.firstName" name="first">
      Example 2: <input [(ngModel)]="person.firstName" [ngModelOptions]="{standalone: true}">

If i now give a name to my <input type="date" [ngModel]="todaysDate | date:'dd-MM-yyyy'" (ngModelChange)="todaysDate = $event" [value]="todaysDate | date:'yyyy-MM-dd'"> the function of filling this field with the acutal date is gone and only TT.MM.YYYY stands there. What can i do?

Answer 1

It should be enough to add:

ngOnInit() {
   this.dateArrival = new Date();
}

and change your HTML so that it will handle by itself the date to string and vice-versa, like suggested in this plunker (taken from another SO post): plnkr.co/edit/s5OMg2olU2yHI246nJOG?p=preview

<input type="date" [ngModel] ="dateArrival | date:'yyyy-MM-dd'" (ngModelChange)="dateArrival = $event">

the ngModelChange will trigger the change automatically and will handle the date convertion aswell. The NgModel , instead, will directly display the date through the date pipe

Answer 2

You can create a variable in your component.ts like:

todaysDate: Date = new Date();

Then in your template:

<input type="text" [value]="todaysDate">