What is the minimum length requirement for a text box in Ionic 2 with Angular 2?

I've been successfully validating a textbox with angular2, and now I'm attempting to set a minimum character limit for the input. However, when I try to do this, I encounter the following error:

Expected validator to return a Promise or Observable

Here is the script that I am working with:

customerNumber: any;

  constructor(public navCtrl: NavController,
              public viewctrl: ViewController,
              public formBuilder: FormBuilder,
              public http: Http,
              public alertCtrl: AlertController,
              public loadingCtrl: LoadingController,
              public toastCtrl: ToastController) {

                this.verifyForm = this.formBuilder.group({
                  customerNumber: ['', Validators.required,Validators.minLength(5)]
                });
  }

And here is the corresponding HTML code:

<ion-item>
 <ion-input type="text" formControlName="CustomerNumber" placeholder="Enter your Customer Number"  [(ngModel)]="customerNumber"></ion-input>
</ion-item>

Answer №1

clientID: any;

constructor(public navCtrl: NavController,
            public viewctrl: ViewController,
            public formBuilder: FormBuilder,
            public http: Http,
            public alertCtrl: AlertController,
            public loadingCtrl: LoadingController,
            public toastCtrl: ToastController) {

              this.clientForm = this.formBuilder.group({
                clientID: ['', Validators.compose([Validators.required, Validators.minLength(6)])]
              });
}

Answer №2

Instead of passing Validators.minLength(5) as the third parameter, you should include it in the array along with Validators.required.

Thus, your code should look like this:

this.verifyForm = this.formBuilder.group({
                  customerNumber: ['', [Validators.required, Validators.minLength(5)]]
                });

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