How to validate white spaces/empty spaces? [Angular 2]

You can create a custom validator to handle this.

new FormControl(field.fieldValue || '', [Validators.required, this.noWhitespaceValidator])

Add noWhitespaceValidator method to your component

public noWhitespaceValidator(control: FormControl) {    const isWhitespace = (control.value || '').trim().length === 0;    const isValid = !isWhitespace;    return isValid ? null : { 'whitespace': true };}

and in the HTML

<div *ngIf="yourForm.hasError('whitespace')">Please enter valid data</div>

Maybe this article can help you http://blog.angular-university.io/introduction-to-angular-2-forms-template-driven-vs-model-driven/

In this approach, you have to use FormControl then watch for value changes and then apply your mask to the value. An example should be:

...form: FormGroup;...ngOnInit(){    this.form.valueChanges            .map((value) => {                // Here you can manipulate your value                value.firstName = value.firstName.trim();                return value;            })            .filter((value) => this.form.valid)            .subscribe((value) => {               console.log("Model Driven Form valid value: vm = ",JSON.stringify(value));            });}

Prevent user to enter space in textbox in Angular 6

<input type="text" (keydown.space)="$event.preventDefault();" required />