Google pay integration in Flutter: paymentResult from Google is not valid JSON? - flutter

Question

I'm trying to integrate Google Pay in my Flutter App following this official tutorial from Google:
https://developers.googleblog.com/2021/05/google-pay-introduces-flutter-plugin-for-payments.html
It works so far that I receive the paymentResult that is mentioned at the very end of the tutorial:
// In your Stateless Widget class or State
void onGooglePayResult(paymentResult) {
// Send the resulting Google Pay token to your server or PSP
}
When I log the paymentResult (paymentResult.toString()) it looks like this:
{apiVersion: 2, apiVersionMinor: 0, paymentMethodData: {description: Visa7001, info: {billingAddress: {address1: myStreet 11, address2: , address3: , administrativeArea: , countryCode: DE, locality: myCity, name: myName, phoneNumber: myNumber, postalCode: myCode, sortingCode: }, cardDetails: myDetails, cardNetwork: VISA}, tokenizationData: {token: examplePaymentMethodToken, type: PAYMENT_GATEWAY}, type: CARD}}
This looks good, now I want to parse this response, but it doesn't work with a JSON decoding, because the keys are not in quotation marks (apiVersion instead of "apiVersion").
According to the tutorial I need the token value (=examplePaymentMethodToken), and for my app I also want to access the user information like name and address, so that my user doesn't have to type in everything himself.
What type is the paymentResult if it's not JSON? How can I parse it?
P.S. I know Google did no mistake here, but their tutorial could really be a bit longer...
I'm using the latest pay package: pay: ^1.0.10
UPDATE:
I found a way to transform the paymentResult to a Map, but when I iterate over the Map it never gets to the third entry:
void onGooglePayResult(paymentResult) {
Map<String, dynamic> resMap = Map<String, dynamic>.from(paymentResult);
MyPaymentResult gPay = new MyPaymentResult();
log('resMap entries: ' + resMap.entries.toString());
resMap.entries.forEach((element) {
log("next key: " + element.key);
if (element.key == "apiVersion") {
log("Api Version found: " + element.value.toString());
gPay.apiVersion = element.value;
} else if (element.key == "apiVersionMinor") {
log("apiVersionMinor found: " + element.value.toString());
gPay.apiVersionMinor = element.value;
} else if (element.key == "paymentMethodData") {
log("paymentMethodData found");
}
}
}
The log:
[log] resMap entries: (MapEntry(apiVersion: 2), MapEntry(apiVersionMinor: 0), MapEntry(paymentMethodData: {description: Visa •••• 7001, info: {billingAddress: {address1: ...... }, cardDetails: 7001, cardNetwork: VISA}, tokenizationData: {token: examplePaymentMethodToken, type: PAYMENT_GATEWAY}, type: CARD}))
[log] next key: apiVersion
[log] Api Version found: 2
[log] next key: apiVersionMinor
[log] apiVersionMinor found: 0
The third entry never gets logged, altough it's in the logged Map??
Is there a easier way to convert a map to an Object?

Answer 1

This works, but this can't be the best solution:
void onGooglePayResult(paymentResult) {
log("Received result!! ${paymentResult.toString()}");
Map<String, dynamic> resMap = Map<String, dynamic>.from(paymentResult);
int apiVersion = resMap['apiVersion'];
int apiVersionMinor = resMap['apiVersionMinor'];
Map<String, dynamic> paymentMethodDataMap =
Map<String, dynamic>.from(resMap['paymentMethodData']);
String description = paymentMethodDataMap['description'];
String type = paymentMethodDataMap['type'];
Map<String, dynamic> infoMap =
Map<String, dynamic>.from(paymentMethodDataMap['info']);
String cardDetails = infoMap['cardDetails'];
String cardNetwork = infoMap['cardNetwork'];
Map<String, dynamic> tokenizationDataMap =
Map<String, dynamic>.from(paymentMethodDataMap['tokenizationData']);
String token = tokenizationDataMap['token'];
String tokenType = tokenizationDataMap['type'];
Map<String, dynamic> billingAddressMap =
Map<String, dynamic>.from(infoMap['billingAddress']);
String address1 = billingAddressMap['address1'];
String address2 = billingAddressMap['address2'];
String address3 = billingAddressMap['address3'];
String administrativeArea = billingAddressMap['administrativeArea'];
String countryCode = billingAddressMap['countryCode'].toString();
String locality = billingAddressMap['locality'];
String name = billingAddressMap['name'];
String phoneNumber = billingAddressMap['phoneNumber'];
int postalCode = int.parse(billingAddressMap['postalCode']);
String sortingCode = billingAddressMap['sortingCode'];
BillingAddress billingAddress = new BillingAddress(
address1,
address2,
address3,
administrativeArea,
countryCode,
locality,
name,
phoneNumber,
postalCode,
sortingCode);
GPayInfo gPayInfo =
new GPayInfo(billingAddress, cardDetails, cardNetwork);
GPayTokenizationData tokenizationData =
new GPayTokenizationData(token, tokenType);
PaymentMethodData paymentMethodData =
new PaymentMethodData(description, gPayInfo, tokenizationData);
GooglePayPaymentResult gPay = new GooglePayPaymentResult(
apiVersion, apiVersionMinor, paymentMethodData, type);
log(gPay.paymentMethodData.tokenizationData.token);
}
Resulting log: [log] examplePaymentMethodToken (which is what I was searching for)