implement financial connection methods in the plugin

example/lib/screens/financial_connections.dart/financial_connections_session_screen.dart

@@ -0,0 +1,133 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_stripe/flutter_stripe.dart';
+import 'package:http/http.dart' as http;
+import 'package:stripe_example/widgets/example_scaffold.dart';
+import 'package:stripe_example/widgets/loading_button.dart';
+
+import '../../config.dart';
+import '../../widgets/response_card.dart';
+
+class FinancialConnectionsScreen extends StatefulWidget {
+  const FinancialConnectionsScreen({Key? key}) : super(key: key);
+
+  @override
+  State<FinancialConnectionsScreen> createState() =>
+      _FinancialConnectionsScreenState();
+}
+
+class _FinancialConnectionsScreenState
+    extends State<FinancialConnectionsScreen> {
+  late String response;
+
+  @override
+  void initState() {
+    response = '';
+    super.initState();
+  }
+
+  Future<Map<String, dynamic>> _financialConnectionsSheet() async {
+    final url = Uri.parse('$kApiUrl/financial-connections-sheet');
+    final response = await http.post(
+      url,
+      headers: {
+        'Content-Type': 'application/json',
+      },
+    );
+
+    return json.decode(response.body);
+  }
+
+  Future<void> _collectAccount(BuildContext context) async {
+    // Precondition:
+    // 1. Make sure to create a financial connection session on the backend and
+    // forward the client secret of the session to the app.
+    final result = await _financialConnectionsSheet();
+    final clientSecret = await result['clientSecret'];
+
+    // 2. use the client secret to confirm the payment and handle the result.
+    try {
+      final result = await Stripe.instance.collectFinancialConnectionsAccounts(
+        clientSecret: clientSecret,
+      );
+
+      setState(() {
+        response = result.toString();
+      });
+    } on Exception catch (e) {
+      if (e is StripeException) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('Error from Stripe: ${e.error.localizedMessage}'),
+          ),
+        );
+      } else {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('Unforeseen error: ${e}'),
+          ),
+        );
+      }
+    }
+  }
+  Future<void> _collectBankToken(BuildContext context) async {
+    // Precondition:
+    // 1. Make sure to create a financial connection session on the backend and
+    // forward the client secret of the session to the app.
+    final result = await _financialConnectionsSheet();
+    final clientSecret = await result['clientSecret'];
+
+    // 2. use the client secret to confirm the payment and handle the result.
+    try {
+      final result = await Stripe.instance.collectBankAccountToken(
+        clientSecret: clientSecret,
+      );
+
+      setState(() {
+        response = result.toString();
+      });
+    } on Exception catch (e) {
+      if (e is StripeException) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('Error from Stripe: ${e.error.localizedMessage}'),
+          ),
+        );
+      } else {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('Unforeseen error: ${e}'),
+          ),
+        );
+      }
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ExampleScaffold(
+      title: 'Financial connections',
+      tags: ['Financial connections'],
+      padding: EdgeInsets.all(16),
+      children: [
+        LoadingButton(
+          onPressed: () async {
+            await _collectAccount(context);
+          },
+          text: 'Collect financial account',
+        ),
+
+        LoadingButton(
+          onPressed: () async {
+            await _collectBankToken(context);
+          },
+          text: 'Collect banktoken',
+        ),
+        Divider(),
+        SizedBox(height: 20),
+        ResponseCard(response: response),
+      ],
+    );
+  }
+}

example/lib/screens/screens.dart

@@ -20,6 +20,7 @@ import 'card_payments/custom_card_payment_screen.dart';
 import 'card_payments/no_webhook_payment_cardform_screen.dart';
 import 'card_payments/no_webhook_payment_screen.dart';
 import 'card_payments/webhook_payment_screen.dart';
+import 'financial_connections.dart/financial_connections_session_screen.dart';
 import 'others/cvc_re_collection_screen.dart';
 import 'others/legacy_token_bank_screen.dart';
 import 'others/legacy_token_card_screen.dart';
@@ -251,6 +252,19 @@ class Example extends StatelessWidget {
       //   builder: (context) => WeChatPayScreen(),
       // ),
     ]),
+    ExampleSection(
+      title: 'Financial connections',
+      children: [
+        Example(
+          title: 'Financial connection sessions',
+          builder: (_)=> FinancialConnectionsScreen(),
+          platformsSupported: [
+            DevicePlatform.android,
+            DevicePlatform.ios,
+          ],
+        ),
+      ],
+    ),
     ExampleSection(title: 'Others', children: [
       Example(
         title: 'Setup Future Payment',

packages/stripe/lib/src/stripe.dart

@@ -443,6 +443,39 @@ class Stripe {
     return await _platform.canAddToWallet(last4);
   }
 
+  /// Call the financial connections authentication flow in order to collect a US bank account to enhance payouts.
+  ///
+  /// Needs `clientSecret` of the stripe financial connections sessions.
+  /// For more info see [Add a Financial Connections Account to a US Custom Connect](https://stripe.com/docs/financial-connections/connect-payouts).
+  ///
+  ///  Throws [StripeError] in case creating the token fails.
+
+  Future<FinancialConnectionTokenResult> collectBankAccountToken(
+      {required String clientSecret}) async {
+    try {
+      return _platform.collectBankAccountToken(clientSecret: clientSecret);
+    } on StripeError {
+      rethrow;
+    }
+  }
+
+  /// Call the financial connections authentication flow in order to collect the user account data.
+  ///
+  /// Needs `clientSecret` of the stripe financial connections sessions.
+  /// For more info see: [Collect an account to build data-powered products](https://stripe.com/docs/financial-connections/other-data-powered-products)
+  ///
+  /// Throws [StripeError] in case creating the token fails.
+
+  Future<FinancialConnectionSessionResult> collectFinancialConnectionsAccounts(
+      {required String clientSecret}) async {
+    try {
+      return _platform.collectFinancialConnectionsAccounts(
+          clientSecret: clientSecret);
+    } on StripeError {
+      rethrow;
+    }
+  }
+
   FutureOr<void> _awaitForSettings() {
     if (_needsSettings) {
       _settingsFuture = applySettings();

packages/stripe_platform_interface/lib/src/method_channel_stripe.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 import 'package:flutter/services.dart';
 import 'package:stripe_platform_interface/src/models/ach_params.dart';
 import 'package:stripe_platform_interface/src/models/create_token_data.dart';
+import 'package:stripe_platform_interface/src/models/financial_connections.dart';
 import 'package:stripe_platform_interface/src/models/google_pay.dart';
 import 'package:stripe_platform_interface/src/models/wallet.dart';
 import 'package:stripe_platform_interface/src/result_parser.dart';
@@ -381,6 +382,36 @@ class MethodChannelStripe extends StripePlatform {
       ),
     );
   }
+
+  @override
+  Future<FinancialConnectionTokenResult> collectBankAccountToken(
+      {required String clientSecret}) async {
+    final result = await _methodChannel
+        .invokeMapMethod<String, dynamic>('collectBankAccountToken', {
+      'clientSecret': clientSecret,
+    });
+
+    if (result!.containsKey('error')) {
+      throw ResultParser<void>(parseJson: (json) => {}).parseError(result);
+    }
+
+    return FinancialConnectionTokenResult.fromJson(result);
+  }
+
+  @override
+  Future<FinancialConnectionSessionResult> collectFinancialConnectionsAccounts(
+      {required String clientSecret}) async {
+    final result = await _methodChannel.invokeMapMethod<String, dynamic>(
+        'collectFinancialConnectionsAccounts', {
+      'clientSecret': clientSecret,
+    });
+
+    if (result!.containsKey('error')) {
+      throw ResultParser<void>(parseJson: (json) => {}).parseError(result);
+    }
+
+    return FinancialConnectionSessionResult.fromJson(result);
+  }
 }
 
 class MethodChannelStripeFactory {

packages/stripe_platform_interface/lib/src/models/card_field_input.dart

@@ -53,7 +53,8 @@ class CardStyle with _$CardStyle {
         Color? placeholderColor,
   }) = _CardStyleConstructor;
 
-  factory CardStyle.fromJson(Map<String, dynamic> json) => _$CardStyleFromJson(json);
+  factory CardStyle.fromJson(Map<String, dynamic> json) =>
+      _$CardStyleFromJson(json);
 
   CardStyle._();
 
@@ -114,7 +115,8 @@ class CardFormStyle with _$CardFormStyle {
         Color? placeholderColor,
   }) = _CardFormStyleConstructor;
 
-  factory CardFormStyle.fromJson(Map<String, dynamic> json) => _$CardFormStyleFromJson(json);
+  factory CardFormStyle.fromJson(Map<String, dynamic> json) =>
+      _$CardFormStyleFromJson(json);
 
   CardFormStyle._();
 
@@ -150,7 +152,8 @@ class CardPlaceholder with _$CardPlaceholder {
     String? postalCode,
   }) = _CardPlaceholderConstructor;
 
-  factory CardPlaceholder.fromJson(Map<String, dynamic> json) => _$CardPlaceholderFromJson(json);
+  factory CardPlaceholder.fromJson(Map<String, dynamic> json) =>
+      _$CardPlaceholderFromJson(json);
 
   CardPlaceholder._();
 
@@ -209,16 +212,19 @@ class CardFieldInputDetails with _$CardFieldInputDetails {
     @Default(CardValidationState.Unknown) CardValidationState validNumber,
   }) = _CardFieldInputDetails;
 
-  factory CardFieldInputDetails.fromJson(Map<String, dynamic> json) => _$CardFieldInputDetailsFromJson(json);
+  factory CardFieldInputDetails.fromJson(Map<String, dynamic> json) =>
+      _$CardFieldInputDetailsFromJson(json);
 }
 
 /// Used to communicate with the card handler on the native platform side when focus changes.
 @freezed
 class CardFieldFocusName with _$CardFieldFocusName {
   @JsonSerializable(explicitToJson: true)
-  factory CardFieldFocusName({CardFieldName? focusedField}) = _CardFieldFocusName;
+  factory CardFieldFocusName({CardFieldName? focusedField}) =
+      _CardFieldFocusName;
 
-  factory CardFieldFocusName.fromJson(Map<String, dynamic> json) => _$CardFieldFocusNameFromJson(json);
+  factory CardFieldFocusName.fromJson(Map<String, dynamic> json) =>
+      _$CardFieldFocusNameFromJson(json);
 }
 
 /// Enum representing the different fiels on the card field.

packages/stripe_platform_interface/lib/src/models/create_token_data.dart

@@ -215,7 +215,7 @@ class BankAccount with _$BankAccount {
     BankAccountStatus? status,
 
     /// Uniquely identifies the particular bank account.
-    /// 
+    ///
     /// You can use this to check whether or not two bank accounts are the same.
     String? fingerprint,
 

packages/stripe_platform_interface/lib/src/models/financial_connections.dart

@@ -43,7 +43,7 @@ class FinancialConnectionSession with _$FinancialConnectionSession {
     required String clientSecret,
 
     /// When `true` the object exists in livemode and when false the object exists in test mode.
-    required String livemode,
+    required bool livemode,
 
     /// The accounts that were collected as part of this session
     required List<FinancialConnectionAccount> accounts,
@@ -64,7 +64,7 @@ class FinancialConnectionBankAccountToken
     BankAccount? bankAccount,
 
     /// When `true` the object exists in livemode and when false the object exists in test mode.
-    required String livemode,
+    required bool livemode,
 
     /// Unique id for this token.
     String? id,
@@ -184,24 +184,24 @@ enum AccountCategory { cash, credit, investment, other }
 
 enum AccountSubcategory {
   checking,
-  credit_card,
-  line_of_credit,
+  creditCard,
+  lineOfCredit,
   mortgage,
   other,
   savings,
 }
 
 enum FinancialConnectionsPaymentMethodType {
-  us_bank_account,
+  usBankAccount,
   link,
 }
 
 enum AccountPermission {
   balances,
   ownership,
-  payment_method,
+  paymentMethod,
   transactions,
-  account_numbers,
+  accountNumbers,
 }
 
 enum BalanceRefreshStatus { failed, pending, succeeded }