Add creditcard validators

Author: martijn00

lib/l10n/intl_en.arb

@@ -18,5 +18,8 @@
   "numericErrorText": "Value must be numeric.",
   "requiredErrorText": "This field cannot be empty.",
   "urlErrorText": "This field requires a valid URL address.",
-  "phoneErrorText": "This field requires a valid phone number."
+  "phoneErrorText": "This field requires a valid phone number.",
+  "creditCardExpirationDateErrorText": "This field requires a valid expiration date.",
+  "creditCardExpiredErrorText": "This credit card has expired.",
+  "creditCardCVCErrorText": "This field requires a valid CVC code."
 }

lib/src/form_builder_validators.dart

@@ -295,6 +295,40 @@ class FormBuilderValidators {
           ? errorText ?? FormBuilderLocalizations.current.creditCardErrorText
           : null;
 
+  /// [FormFieldValidator] that requires the field's value to be a valid credit card expiration date.
+  static FormFieldValidator<String> creditCardExpirationDate({
+    String? errorText,
+  }) =>
+      (valueCandidate) => true == valueCandidate?.isNotEmpty &&
+              !isCreditCardExpirationDate(valueCandidate!)
+          ? errorText ??
+              FormBuilderLocalizations.current.creditCardExpirationDateErrorText
+          : null;
+
+  /// [FormFieldValidator] that requires the field's value to be a valid credit card expiration date and not expired.
+  static FormFieldValidator<String> creditCardExpirationDateNotExpired({
+    String? errorText,
+  }) =>
+      (valueCandidate) => true == valueCandidate?.isNotEmpty &&
+              !isCreditCardExpirationDate(valueCandidate!) &&
+              !isNotExpiredCreditCardDate(valueCandidate)
+          ? errorText ??
+              FormBuilderLocalizations.current.creditCardExpiredErrorText
+          : null;
+
+  /// [FormFieldValidator] that requires the field's value to be a valid credit card CVC.
+  static FormFieldValidator<String> creditCardCVC({
+    String? errorText,
+  }) =>
+      compose<String>(
+        [
+          minLength(3,
+              errorText: errorText ?? FormBuilderLocalizations.current.creditCardCVCErrorText),
+          maxLength(4,
+              errorText: errorText ?? FormBuilderLocalizations.current.creditCardCVCErrorText),
+        ],
+      );
+
   /// [FormFieldValidator] that requires the field's value to be a valid IP address.
   /// * [version] is a `String` or an `int`.
   static FormFieldValidator<String> ip({
@@ -319,8 +353,8 @@ class FormBuilderValidators {
   static FormFieldValidator<String> phoneNumber({
     String? errorText,
   }) =>
-      (valueCandidate) => true == valueCandidate?.isNotEmpty &&
-              !isPhoneNumber(valueCandidate!)
-          ? errorText ?? FormBuilderLocalizations.current.phoneErrorText
-          : null;
+      (valueCandidate) =>
+          true == valueCandidate?.isNotEmpty && !isPhoneNumber(valueCandidate!)
+              ? errorText ?? FormBuilderLocalizations.current.phoneErrorText
+              : null;
 }

lib/src/utils/validators.dart

@@ -14,6 +14,8 @@ RegExp _creditCard = RegExp(
 
 RegExp _phoneNumber = RegExp(r'^(\+?\d{0,1})?\(?\d{3}\)?[-.\s]\d{3}[-.\s]\d{4}$'); 
 
+RegExp _creditCardExpirationDate = RegExp(r'^[0-1][0-9]/\d{2}$');
+
 int _maxUrlLength = 2083;
 
 /// check if the string [str] is an email
@@ -241,3 +243,44 @@ bool isDate(String str) {
 bool isPhoneNumber(String str) {
   return _phoneNumber.hasMatch(str);
 }
+
+/// check if the string is a valid credit card expiration date
+bool isCreditCardExpirationDate(String str) {
+  // Check if the format matches MM/YY
+  if (!_creditCardExpirationDate.hasMatch(str)) {
+    return false;
+  }
+
+  // Extract month and year from the value
+  final parts = str.split('/').map(int.parse).toList();
+  final month = parts[0];
+  final year = parts[1];
+
+  // Check for valid month (1-12)
+  if (month < 1 || month > 12) {
+    return false;
+  }
+
+  return year > 0;
+}
+
+/// check if the string is not a expired credit card date
+bool isNotExpiredCreditCardDate(String str) {
+  final parts = str.split('/').map(int.parse).toList();
+  final month = parts[0];
+  final year = parts[1];
+
+  final now = DateTime.now();
+  final currentYear = now.year % 100;
+  final currentMonth = now.month;
+
+  if (year < currentYear) {
+    return false;
+  }
+
+  if (year == currentYear && month < currentMonth) {
+    return false;
+  }
+
+  return true;
+}