maskCardNumber function

String maskCardNumber({ required String number, required FMMaskType maskType, })

Mask Card Number

Type: String

Use in the masking process of card number. It requires the card number and mask type and uses these two params to mask the card number.

Implementation

String maskCardNumber({required String number, required FMMaskType maskType}) {
  // getting mask type condition added by the developer
  bool full = maskType == FMMaskType.full;
  bool first4Last4 = maskType == FMMaskType.first4Last4;
  bool first6last2 = maskType == FMMaskType.first6last2;
  bool first2last6 = maskType == FMMaskType.first2last6;
  bool none = maskType == FMMaskType.none;
  String mask = "0000 0000 0000 0000";
  var bufferString = StringBuffer();

  // return the number input without validation to avoid length error
  if (number.length < 8) return number;

  // remove the "/" from number passed buffer
  number = number.replaceAll(" ", "");

  // card number length less than two are not validated to avoid [Out Of Range].
  if (number.length > 2) {
    if (full) {
      mask = "*" * number.length;
    } else if (first4Last4) {
      String first4 = number.substring(0, 4);
      String last4 = number.substring(number.length - 4);
      String maskCount = "*" * (number.length - 8);
      mask = "$first4$maskCount$last4";
    } else if (first6last2) {
      String first6 = number.substring(0, 6);
      String last2 = number.substring(number.length - 2);
      String maskCount = "*" * (number.length - 8);
      mask = "$first6$maskCount$last2";
    } else if (first2last6) {
      String first2 = number.substring(0, 2);
      String last6 = number.substring(number.length - 6);
      String maskCount = "*" * (number.length - 8);
      mask = "$first2$maskCount$last6";
    } else if (none) {
      mask = number;
    }
  }

  // this is to buff the number using space after every 4 characters
  for (int i = 0; i < mask.length; i++) {
    bufferString.write(mask[i]);
    var nonZeroIndexValue = i + 1;
    if (nonZeroIndexValue % 4 == 0 && nonZeroIndexValue != mask.length) {
      bufferString.write(" ");
    }
  }

  // finally return the buffed number
  return bufferString.toString();
}