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This commit is contained in:
Nathan Anderson 2023-11-14 09:58:49 -07:00
parent 41da951be1
commit 88020f4d15
5 changed files with 879 additions and 10 deletions
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295
lib/card_details.dart Normal file
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@ -0,0 +1,295 @@
import 'package:flutter/foundation.dart';
class CardDetails {
CardDetails({required this.cardNumber, required String? securityCode, required this.expirationDate}) {
this.securityCode = int.tryParse(securityCode ?? '');
checkIsValid();
}
factory CardDetails.blank() {
return CardDetails(cardNumber: null, securityCode: null, expirationDate: null);
}
String? cardNumber;
int? securityCode;
String? postalCode;
String? expirationDate;
bool _complete = false;
ValidState _validState = ValidState.blank;
int _lastCheckHash = 0;
CardProvider? provider;
ValidState get validState {
checkIsValid();
return _validState;
}
bool get cardNumberFilled => provider == null || provider?.cardLength == cardNumber?.replaceAll(' ', '').length;
bool get isComplete {
checkIsValid();
return _complete;
}
int get minInnLength => 1;
int get maxINNLength => 4;
void checkIsValid() {
try {
int currentHash = hash;
if (currentHash == _lastCheckHash) {
return;
}
_lastCheckHash = currentHash;
if (cardNumber == null && expirationDate == null && securityCode == null && postalCode == null) {
_complete = false;
_validState = ValidState.blank;
return;
}
final nums = cardNumber!
.replaceAll(' ', '')
.split('')
.map(
(i) => int.parse(i),
)
.toList();
if (!luhnAlgorithmCheck(nums)) {
_complete = false;
_validState = ValidState.invalidCard;
return;
}
if (cardNumber == null || !cardNumberFilled) {
_complete = false;
_validState = ValidState.missingCard;
return;
}
if (expirationDate == null) {
_complete = false;
_validState = ValidState.missingDate;
return;
}
final expSplits = expirationDate!.split('/');
if (expSplits.length != 2 || expSplits.last == '') {
_complete = false;
_validState = ValidState.missingDate;
return;
}
final date = DateTime(2000 + int.parse(expSplits.last),
int.parse(expSplits.first[0] == '0' ? expSplits.first[1] : expSplits.first));
if (date.isBefore(DateTime.now())) {
_complete = false;
_validState = ValidState.dateTooEarly;
return;
} else if (date.isAfter(DateTime.now().add(const Duration(days: 365 * 50)))) {
_complete = false;
_validState = ValidState.dateTooLate;
return;
}
if (securityCode == null) {
_complete = false;
_validState = ValidState.missingCVC;
return;
}
if (postalCode == null) {
_complete = false;
_validState = ValidState.missingZip;
return;
}
if (!RegExp(r'^\d{5}(-\d{4})?$').hasMatch(postalCode!)) {
_complete = false;
_validState = ValidState.invalidZip;
return;
}
_complete = true;
_validState = ValidState.ok;
} catch (err, st) {
if (kDebugMode) {
print('Error while validating CardDetails: $err\n$st');
}
_complete = false;
_validState = ValidState.error;
}
}
int get hash {
return Object.hash(cardNumber, expirationDate, securityCode, postalCode);
}
void detectCardProvider() {
bool found = false;
if (cardNumber == null) {
return;
}
for (var cardPvd in providers) {
if (cardPvd.INN_VALID_NUMS != null) {
// trim card number to correct length
String trimmedNum = cardNumber!;
String innNumStr = '${cardPvd.INN_VALID_NUMS!.first}';
if (trimmedNum.length > innNumStr.length) {
trimmedNum = trimmedNum.substring(0, innNumStr.length);
}
final num = int.tryParse(trimmedNum);
if (num == null) continue;
if (cardPvd.INN_VALID_NUMS!.contains(num)) {
provider = cardPvd;
found = true;
break;
}
}
if (cardPvd.INN_VALID_RANGES != null) {
// trim card number to correct length
String trimmedNum = cardNumber!;
String innNumStr = '${cardPvd.INN_VALID_RANGES!.first.low}';
if (trimmedNum.length > innNumStr.length) {
trimmedNum = trimmedNum.substring(0, innNumStr.length);
}
final num = int.tryParse(trimmedNum);
if (num == null) continue;
if (cardPvd.INN_VALID_RANGES!.any((range) => range.isWithin(num))) {
provider = cardPvd;
found = true;
break;
}
}
}
if (!found) provider = null;
// print('Got provider $provider');
}
@override
String toString() {
return 'Number: "$cardNumber" - Exp: "$expirationDate" CVC: $securityCode Zip: "$postalCode"';
}
}
enum ValidState {
ok,
error,
blank,
missingCard,
invalidCard,
missingDate,
dateTooEarly,
dateTooLate,
missingCVC,
invalidCVC,
missingZip,
invalidZip,
}
enum CardProviderID {
AmericanExpress,
DinersClub,
DiscoverCard,
Mastercard,
JCB,
Visa,
}
class CardProvider {
CardProviderID id;
List<int>? INN_VALID_NUMS;
List<Range>? INN_VALID_RANGES;
int cardLength;
int cvcLength;
CardProvider(
{required this.id,
required this.cardLength,
required this.cvcLength,
this.INN_VALID_NUMS,
this.INN_VALID_RANGES}) {
// Must provide one or the other
assert(INN_VALID_NUMS != null || INN_VALID_RANGES != null);
// Do not provide empty list of valid nums
assert(INN_VALID_NUMS == null || INN_VALID_NUMS!.isNotEmpty);
}
@override
String toString() {
return id.toString();
}
}
class Range {
int high;
int low;
Range({required this.low, required this.high}) {
assert(low <= high);
}
bool isWithin(int val) {
return low <= val && val <= high;
}
}
List<CardProvider> providers = [
CardProvider(
id: CardProviderID.AmericanExpress,
cardLength: 15,
cvcLength: 4,
INN_VALID_NUMS: [34, 37],
),
CardProvider(
id: CardProviderID.DinersClub,
cardLength: 16,
cvcLength: 3,
INN_VALID_NUMS: [30, 36, 38, 39],
),
CardProvider(
id: CardProviderID.DiscoverCard,
cardLength: 16,
cvcLength: 3,
INN_VALID_NUMS: [60, 65],
INN_VALID_RANGES: [Range(low: 644, high: 649)],
),
CardProvider(
id: CardProviderID.JCB,
cardLength: 16,
cvcLength: 3,
INN_VALID_NUMS: [35],
),
CardProvider(
id: CardProviderID.Mastercard,
cardLength: 16,
cvcLength: 3,
INN_VALID_RANGES: [Range(low: 22, high: 27), Range(low: 51, high: 55)],
),
CardProvider(
id: CardProviderID.Visa,
cardLength: 16,
cvcLength: 3,
INN_VALID_NUMS: [4],
)
];
// https://en.wikipedia.org/wiki/Luhn_algorithm
// The Luhn algorithm is used in industry to check
// for valid credit / debit card numbers
//
// The algorithm adds together all the numbers, every
// other number is doubled, then the sum is checked to
// see if it is a multiple of 10.
bool luhnAlgorithmCheck(List<int> digits) {
int sum = 0;
bool isSecond = false;
for (int i = digits.length - 1; i >= 0; i--) {
int d = digits[i];
if (isSecond) {
d *= 2;
if (d > 9) {
d -= 9;
}
}
sum += d;
isSecond = !isSecond;
}
return (sum % 10) == 0;
}

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lib/card_provider_icon.dart Normal file
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500
lib/stripe_native_card_field.dart
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@ -1,7 +1,499 @@
library stripe_native_card_field;
/// A Calculator.
class Calculator {
/// Returns [value] plus 1.
int addOne(int value) => value + 1;
import 'dart:async';
import 'card_details.dart';
import 'card_provider_icon.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
enum CardEntryStep { number, exp, cvc, postal }
class CardTextField extends StatefulWidget {
const CardTextField({Key? key, required this.width, this.height, this.inputDecoration}) : super(key: key);
final InputDecoration? inputDecoration;
final double width;
final double? height;
@override
State<CardTextField> createState() => _CardTextFieldState();
}
class _CardTextFieldState extends State<CardTextField> {
late TextEditingController _cardNumberController;
late TextEditingController _expirationController;
late TextEditingController _securityCodeController;
late TextEditingController _postalCodeController;
late FocusNode _cardNumberFocusNode;
late FocusNode _expirationFocusNode;
late FocusNode _securityCodeFocusNode;
late FocusNode _postalCodeFocusNode;
final double _cardFieldWidth = 180.0;
final double _expirationFieldWidth = 70.0;
final double _securityFieldWidth = 40.0;
final double _postalFieldWidth = 100.0;
late final double _internalFieldWidth;
late final bool _isWideFormat;
bool _showBorderError = false;
String? _validationErrorText;
final _currentCardEntryStepController = StreamController<CardEntryStep>();
final _horizontalScrollController = ScrollController();
CardEntryStep _currentStep = CardEntryStep.number;
final _formFieldKey = GlobalKey<FormState>();
final CardDetails _cardDetails = CardDetails.blank();
final normalBoxDecoration = BoxDecoration(
color: Color(0xfff6f9fc),
border: Border.all(
color: Color(0xffdde0e3),
width: 2.0,
),
borderRadius: BorderRadius.circular(8.0),
);
final errorBoxDecoration = BoxDecoration(
color: Color(0xfff6f9fc),
border: Border.all(
color: Colors.red,
width: 2.0,
),
borderRadius: BorderRadius.circular(8.0),
);
final TextStyle _errorTextStyle = TextStyle(color: Colors.red, fontSize: 14);
final TextStyle _normalTextStyle = TextStyle(color: Colors.black87, fontSize: 14);
@override
void initState() {
_cardNumberController = TextEditingController();
_expirationController = TextEditingController();
_securityCodeController = TextEditingController();
_postalCodeController = TextEditingController();
_cardNumberFocusNode = FocusNode();
_expirationFocusNode = FocusNode();
_securityCodeFocusNode = FocusNode();
_postalCodeFocusNode = FocusNode();
_currentCardEntryStepController.stream.listen(
_onStepChange,
);
RawKeyboard.instance.addListener(_backspaceTransitionListener);
_isWideFormat = widget.width >= 450;
if (_isWideFormat) {
_internalFieldWidth = widget.width + 80;
} else {
_internalFieldWidth = _cardFieldWidth + _expirationFieldWidth + _securityFieldWidth + _postalFieldWidth + 80;
}
super.initState();
}
@override
void dispose() {
_cardNumberController.dispose();
_expirationController.dispose();
_securityCodeController.dispose();
_cardNumberFocusNode.dispose();
_expirationFocusNode.dispose();
_securityCodeFocusNode.dispose();
RawKeyboard.instance.removeListener(_backspaceTransitionListener);
super.dispose();
}
@override
Widget build(BuildContext context) {
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Form(
key: _formFieldKey,
child: GestureDetector(
onTap: () {
// Focuses to the current field
_currentCardEntryStepController.add(_currentStep);
},
child: Container(
width: widget.width,
height: widget.height ?? 60.0,
decoration: _showBorderError ? errorBoxDecoration : normalBoxDecoration,
child: ClipRect(
child: IgnorePointer(
child: SingleChildScrollView(
controller: _horizontalScrollController,
scrollDirection: Axis.horizontal,
child: SizedBox(
width: _internalFieldWidth,
height: widget.height ?? 60.0,
child: Row(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.start,
children: [
Padding(
padding: const EdgeInsets.symmetric(horizontal: 6.0),
child: CardProviderIcon(
cardDetails: _cardDetails,
),
),
Container(
width: _cardFieldWidth,
child: TextFormField(
focusNode: _cardNumberFocusNode,
controller: _cardNumberController,
keyboardType: TextInputType.number,
style: _isRedText([ValidState.invalidCard, ValidState.missingCard, ValidState.blank])
? _errorTextStyle
: _normalTextStyle,
validator: (content) {
if (content == null || content.isEmpty) {
return null;
}
_cardDetails.cardNumber = content;
if (_cardDetails.validState == ValidState.invalidCard) {
_setValidationState('You card number is invalid.');
} else if (_cardDetails.validState == ValidState.missingCard) {
_setValidationState('Your card number is incomplete.');
}
return null;
},
onChanged: (str) {
final numbers = str.replaceAll(' ', '');
setState(() => _cardDetails.cardNumber = numbers);
if (str.length <= _cardDetails.maxINNLength) {
_cardDetails.detectCardProvider();
}
if (numbers.length == 16) {
_currentCardEntryStepController.add(CardEntryStep.exp);
}
},
inputFormatters: [
LengthLimitingTextInputFormatter(19),
FilteringTextInputFormatter.allow(RegExp('[0-9 ]')),
CardNumberInputFormatter(),
],
decoration: InputDecoration(
hintText: 'Card number',
fillColor: Colors.transparent,
border: InputBorder.none,
),
),
),
if (_isWideFormat)
Flexible(
fit: FlexFit.loose,
// fit: _currentStep == CardEntryStep.number ? FlexFit.loose : FlexFit.tight,
child: AnimatedContainer(
curve: Curves.easeOut,
duration: const Duration(milliseconds: 400),
constraints: _currentStep == CardEntryStep.number
? BoxConstraints.loose(Size(400.0, 1.0))
: BoxConstraints.tight(Size(0, 0)))),
// Spacer(flex: _currentStep == CardEntryStep.number ? 100 : 1),
AnimatedContainer(
duration: const Duration(milliseconds: 125),
width: _expirationFieldWidth,
child: TextFormField(
focusNode: _expirationFocusNode,
controller: _expirationController,
style:
_isRedText([ValidState.dateTooLate, ValidState.dateTooEarly, ValidState.missingDate])
? _errorTextStyle
: _normalTextStyle,
validator: (content) {
if (content == null || content.isEmpty) {
return null;
}
setState(() => _cardDetails.expirationDate = content);
if (_cardDetails.validState == ValidState.dateTooEarly) {
_setValidationState('Your card\'s expiration date is in the past.');
} else if (_cardDetails.validState == ValidState.dateTooLate) {
_setValidationState('Your card\'s expiration year is invalid.');
} else if (_cardDetails.validState == ValidState.missingDate) {
_setValidationState('You must include your card\'s expiration date.');
}
return null;
},
onChanged: (str) {
setState(() => _cardDetails.expirationDate = str);
if (str.length == 5) {
_currentCardEntryStepController.add(CardEntryStep.cvc);
}
},
inputFormatters: [
LengthLimitingTextInputFormatter(5),
FilteringTextInputFormatter.allow(RegExp('[0-9/]')),
CardExpirationFormatter(),
],
decoration: InputDecoration(
hintText: 'MM/YY',
fillColor: Colors.transparent,
border: InputBorder.none,
),
),
),
AnimatedContainer(
duration: const Duration(milliseconds: 250),
width: _securityFieldWidth,
child: TextFormField(
focusNode: _securityCodeFocusNode,
controller: _securityCodeController,
style: _isRedText([ValidState.invalidCVC, ValidState.missingCVC])
? _errorTextStyle
: _normalTextStyle,
validator: (content) {
if (content == null || content.isEmpty) {
return null;
}
setState(() => _cardDetails.securityCode = int.tryParse(content));
if (_cardDetails.validState == ValidState.invalidCVC) {
_setValidationState('Your card\'s security code is invalid.');
} else if (_cardDetails.validState == ValidState.missingCVC) {
_setValidationState('You card\'s security code is incomplete.');
}
return null;
},
onChanged: (str) {
setState(() => _cardDetails.expirationDate = str);
if (str.length == _cardDetails.provider?.cvcLength) {
_currentCardEntryStepController.add(CardEntryStep.postal);
}
},
inputFormatters: [
LengthLimitingTextInputFormatter(
_cardDetails.provider == null ? 4 : _cardDetails.provider!.cvcLength),
FilteringTextInputFormatter.allow(RegExp('[0-9]')),
],
decoration: const InputDecoration(
hintText: 'CVC',
fillColor: Colors.transparent,
border: InputBorder.none,
),
),
),
AnimatedContainer(
duration: const Duration(milliseconds: 250),
width: _postalFieldWidth,
child: TextFormField(
focusNode: _postalCodeFocusNode,
controller: _postalCodeController,
style: _isRedText([ValidState.invalidZip, ValidState.missingZip])
? _errorTextStyle
: _normalTextStyle,
validator: (content) {
print('validate zipcode');
if (content == null || content.isEmpty) {
return null;
}
setState(() => _cardDetails.postalCode = content);
print('checking here\n$_cardDetails');
if (_cardDetails.validState == ValidState.invalidZip) {
_setValidationState('The postal code you entered is not correct.');
} else if (_cardDetails.validState == ValidState.missingZip) {
_setValidationState('You must enter your card\'s postal code.');
}
return null;
},
onChanged: (str) {
print('here');
setState(() => _cardDetails.postalCode = str);
print(_cardDetails.toString());
},
onFieldSubmitted: (_) {
print('finished');
_validateFields();
},
decoration: InputDecoration(
hintText: _currentStep == CardEntryStep.number ? '' : 'Postal Code',
fillColor: Colors.transparent,
border: InputBorder.none,
),
),
),
],
),
),
),
),
),
),
),
),
AnimatedOpacity(
duration: const Duration(milliseconds: 525),
opacity: _validationErrorText == null ? 0.0 : 1.0,
child: Padding(
padding: const EdgeInsets.only(top: 8.0, left: 14.0),
child: Text(
_validationErrorText ?? '',
style: const TextStyle(color: Colors.red),
),
),
),
],
);
}
bool _isRedText(List<ValidState> args) {
return _showBorderError && args.contains(_cardDetails.validState);
}
void _setValidationState(String? text) {
setState(() {
_validationErrorText = text;
_showBorderError = text != null;
});
}
void _validateFields() {
_validationErrorText = null;
_formFieldKey.currentState!.validate();
// Clear up validation state if everything is valid
if (_validationErrorText == null) {
_setValidationState(null);
}
return;
}
void _scrollRow(CardEntryStep step) {
final dur = Duration(milliseconds: 150);
final cur = Curves.easeOut;
final fieldLen = widget.width;
switch (step) {
case CardEntryStep.number:
_horizontalScrollController.animateTo(0.0, duration: dur, curve: cur);
break;
case CardEntryStep.exp:
_horizontalScrollController.animateTo(_cardFieldWidth / 2, duration: dur, curve: cur);
break;
case CardEntryStep.cvc:
_horizontalScrollController.animateTo(_cardFieldWidth / 2 + _expirationFieldWidth, duration: dur, curve: cur);
break;
case CardEntryStep.postal:
_horizontalScrollController.animateTo(_cardFieldWidth / 2 + _expirationFieldWidth + _securityFieldWidth,
duration: dur, curve: cur);
break;
}
}
void _onStepChange(CardEntryStep step) {
if (_currentStep.index < step.index) {
_validateFields();
} else if (_currentStep != step) {
_setValidationState(null);
}
setState(() {
_currentStep = step;
});
switch (step) {
case CardEntryStep.number:
_cardNumberFocusNode.requestFocus();
break;
case CardEntryStep.exp:
_expirationFocusNode.requestFocus();
break;
case CardEntryStep.cvc:
_securityCodeFocusNode.requestFocus();
break;
case CardEntryStep.postal:
_postalCodeFocusNode.requestFocus();
break;
}
if (!_isWideFormat) {
_scrollRow(step);
}
}
void _backspaceTransitionListener(RawKeyEvent value) {
if (!value.isKeyPressed(LogicalKeyboardKey.backspace)) {
return;
}
switch (_currentStep) {
case CardEntryStep.number:
break;
case CardEntryStep.exp:
final expStr = _expirationController.text;
if (expStr.isNotEmpty) break;
_currentCardEntryStepController.add(CardEntryStep.number);
String numStr = _cardNumberController.text;
_cardNumberController.text = numStr.substring(0, numStr.length - 1);
break;
case CardEntryStep.cvc:
final cvcStr = _securityCodeController.text;
if (cvcStr.isNotEmpty) break;
_currentCardEntryStepController.add(CardEntryStep.exp);
final expStr = _expirationController.text;
_expirationController.text = expStr.substring(0, expStr.length - 1);
case CardEntryStep.postal:
final String postalStr = _postalCodeController.text;
if (postalStr.isNotEmpty) break;
_currentCardEntryStepController.add(CardEntryStep.cvc);
final String cvcStr = _securityCodeController.text;
_securityCodeController.text = cvcStr.substring(0, cvcStr.length - 1);
}
}
}
class CardNumberInputFormatter implements TextInputFormatter {
@override
TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
String cardNum = newValue.text;
if (cardNum.length <= 4) return newValue;
cardNum = cardNum.replaceAll(' ', '');
StringBuffer buffer = StringBuffer();
for (int i = 0; i < cardNum.length; i++) {
buffer.write(cardNum[i]);
int nonZeroIndex = i + 1;
if (nonZeroIndex % 4 == 0 && nonZeroIndex != cardNum.length) {
buffer.write(' ');
}
}
return newValue.copyWith(text: buffer.toString(), selection: TextSelection.collapsed(offset: buffer.length));
}
}
class CardExpirationFormatter implements TextInputFormatter {
@override
TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
String cardExp = newValue.text;
if (cardExp.length == 1) {
if (cardExp[0] == '0' || cardExp[0] == '1') {
return newValue;
} else {
cardExp = '0$cardExp';
}
}
if (cardExp.length == 2 && oldValue.text.length == 3) return newValue;
// Auto delete the slash on backspace
// if (cardExp.length == 3 && oldValue.text.length == 4 && cardExp[2] == '/') {
// return newValue.copyWith(
// text: cardExp.substring(0, 2), selection: TextSelection.collapsed(offset: cardExp.length - 1));
// }
cardExp = cardExp.replaceAll('/', '');
StringBuffer buffer = StringBuffer();
for (int i = 0; i < cardExp.length; i++) {
buffer.write(cardExp[i]);
int nonZeroIndex = i + 1;
if (nonZeroIndex == 2) {
buffer.write('/');
}
}
return newValue.copyWith(text: buffer.toString(), selection: TextSelection.collapsed(offset: buffer.length));
}
}

1
pubspec.yaml
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@ -10,6 +10,7 @@ environment:
dependencies:
flutter:
sdk: flutter
flutter_svg: ^2.0.9
dev_dependencies:
flutter_test:

7
test/stripe_native_card_field_test.dart
View File

@ -3,10 +3,7 @@ import 'package:flutter_test/flutter_test.dart';
import 'package:stripe_native_card_field/stripe_native_card_field.dart';
void main() {
test('adds one to input values', () {
final calculator = Calculator();
expect(calculator.addOne(2), 3);
expect(calculator.addOne(-7), -6);
expect(calculator.addOne(0), 1);
test('CardDetails:', () {
});
}