angular validator not empty code example

Example 1: angular form validation whitespace

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

Example 2: validation minlength angular

Validators.minLength(9)