code: function onFocus() {
                  var value = ngModelCtrl.$modelValue;
                  if (!angular.isUndefined(value)) {
                      ngModelCtrl.$viewValue = (""+value).replace(".", decimalSeparator);
                      ngModelCtrl.$render();
                  }
              }
docs: Function for handeling the focus (enter) event on the control.
  On focus show the value without the group separators.