Number validator file

number-validator.ts

import { AbstractControl, Validators, ValidatorFn } from '@angular/forms';

function isPresent(obj: any): boolean {
  return obj !== undefined && obj !== null;
}

export const number: ValidatorFn = (control: AbstractControl): {[key: string]: boolean} => {
  if (isPresent(Validators.required(control))) return null;

  let v: string = control.value;
  return /^(?:-?\d+|-?\d{1,3}(?:,\d{3})+)?(?:\.\d+)?$/.test(v) ? null : {'number': true};
};