fix: userCanPay without existing payment methods

pay/lib/src/pay.dart

@@ -47,10 +47,14 @@ class Pay {
   /// This method wraps the [userCanPay] method in the platform interface. It
   /// makes sure that the [provider] exists and is available in the platform
   /// running the logic.
-  Future<bool> userCanPay(PayProvider provider) async {
+  ///
+  /// [existingPaymentMethodRequired]:
+  ///   - If true (default), only returns true if a supported payment method is available.
+  ///   - If false, returns true if the device and user support the payment method, even if none is currently available.
+  Future<bool> userCanPay(PayProvider provider, {bool existingPaymentMethodRequired = true}) async {
     await throwIfProviderIsNotDefined(provider);
     if (supportedProviders[defaultTargetPlatform]!.contains(provider)) {
-      return _payPlatform.userCanPay(_configurations[provider]!);
+      return _payPlatform.userCanPay(_configurations[provider]!, existingPaymentMethodRequired: existingPaymentMethodRequired);
     }
 
     return Future.value(false);

pay/lib/src/widgets/pay_button.dart

@@ -51,6 +51,10 @@ abstract class PayButton extends StatefulWidget {
   /// a user can pay with it and the button loads.
   final Widget? loadingIndicator;
 
+  /// Whether an existing payment method is required to show this button.
+  /// If false, the button is shown whenever the device supports the payment method.
+  final bool existingPaymentMethodRequired;
+
   /// Initializes the button and the payment client that handles the requests.
   PayButton({
     super.key,
@@ -63,6 +67,7 @@ abstract class PayButton extends StatefulWidget {
     this.onError,
     this.childOnError,
     this.loadingIndicator,
+    this.existingPaymentMethodRequired = false,
   }) : _payClient = Pay({buttonProvider: paymentConfiguration});
 
   /// Determines the list of supported platforms for the button.
@@ -136,7 +141,10 @@ class _PayButtonState extends State<PayButton> {
 
   Future<bool> _userCanPay() async {
     try {
-      return await widget._payClient.userCanPay(widget.buttonProvider);
+      return await widget._payClient.userCanPay(
+        widget.buttonProvider,
+        existingPaymentMethodRequired: widget.existingPaymentMethodRequired,
+      );
     } catch (error) {
       widget.onError?.call(error);
       rethrow;

pay_android/android/src/main/kotlin/io/flutter/plugins/pay_android/GooglePayHandler.kt

@@ -66,9 +66,11 @@ class GooglePayHandler(private val activity: Activity) : PluginRegistry.Activity
         fun buildPaymentProfile(
             paymentProfileString: String,
             onlyIncludeFields: List<String>,
-            paymentItems: List<Map<String, Any?>>? = null
+            paymentItems: List<Map<String, Any?>>? = null,
+            existingPaymentMethodRequired: Boolean = false
         ): JSONObject {
             val rawPaymentProfile = JSONObject(paymentProfileString)
+            rawPaymentProfile.put("existingPaymentMethodRequired", existingPaymentMethodRequired)
 
             // Add payment information
             paymentItems?.find { it["type"] == "total" }?.let {
@@ -128,8 +130,9 @@ class GooglePayHandler(private val activity: Activity) : PluginRegistry.Activity
      *
      * @param result callback to communicate back with the Dart end in Flutter.
      * @param paymentProfileString the payment configuration object in [String] format.
+     * @param existingPaymentMethodRequired whether the user must have an existing payment method.
      */
-    fun isReadyToPay(result: Result, paymentProfileString: String) {
+    fun isReadyToPay(result: Result, paymentProfileString: String, existingPaymentMethodRequired: Boolean = false) {
 
         // Construct profile and client
         val paymentProfile = buildPaymentProfile(
@@ -139,7 +142,7 @@ class GooglePayHandler(private val activity: Activity) : PluginRegistry.Activity
                 "apiVersionMinor",
                 "allowedPaymentMethods",
                 "existingPaymentMethodRequired"
-            )
+            ), existingPaymentMethodRequired = existingPaymentMethodRequired
         )
 
         val client = paymentClientForProfile(paymentProfile)

pay_android/android/src/main/kotlin/io/flutter/plugins/pay_android/PayMethodCallHandler.kt

@@ -75,7 +75,12 @@ class PayMethodCallHandler private constructor(
     @Suppress("UNCHECKED_CAST")
     override fun onMethodCall(call: MethodCall, result: Result) {
         when (call.method) {
-            METHOD_USER_CAN_PAY -> googlePayHandler.isReadyToPay(result, call.arguments()!!)
+            METHOD_USER_CAN_PAY -> {
+                val args = call.arguments as? Map<String, Any>
+                val paymentProfileString = args!!["paymentConfiguration"] as String
+                val existingPaymentMethodRequired = args!!["existingPaymentMethodRequired"] as? Boolean ?: false
+                googlePayHandler.isReadyToPay(result, paymentProfileString, existingPaymentMethodRequired)
+            }
             METHOD_SHOW_PAYMENT_SELECTOR -> {
                 if (eventChannelIsActive) {
                     val arguments = call.arguments<Map<String, Any>>()!!

pay_ios/ios/pay_ios/Sources/pay_ios/PayPlugin.swift

@@ -21,34 +21,38 @@ import UIKit
 /// A class that receives and handles calls from Flutter to complete the payment.
 public class PayPlugin: NSObject, FlutterPlugin {
   private static let methodChannelName = "plugins.flutter.io/pay"
-  
+
   private let methodUserCanPay = "userCanPay"
   private let methodShowPaymentSelector = "showPaymentSelector"
-  
+
   private let paymentHandler = PaymentHandler()
-  
+
   public static func register(with registrar: FlutterPluginRegistrar) {
     let messenger = registrar.messenger()
     let channel = FlutterMethodChannel(name: methodChannelName, binaryMessenger: messenger)
     registrar.addMethodCallDelegate(PayPlugin(), channel: channel)
-    
+
     // Register the PlatformView to show the Apple Pay button.
     let buttonFactory = ApplePayButtonViewFactory(messenger: messenger)
     registrar.register(buttonFactory, withId: ApplePayButtonView.buttonMethodChannelName)
   }
-  
+
   public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
     switch call.method {
     case methodUserCanPay:
-      result(paymentHandler.canMakePayments(call.arguments as! String))
-
+      let args = call.arguments as! [String: Any]
+
+      result(paymentHandler.canMakePayments(
+        args["paymentConfiguration"] as! String,
+        existingPaymentMethodRequired: args["existingPaymentMethodRequired"] as? Bool ?? false)
+      )
     case methodShowPaymentSelector:
       let arguments = call.arguments as! [String: Any]
       paymentHandler.startPayment(
         result: result,
         paymentConfiguration: arguments["payment_profile"] as! String,
         paymentItems: arguments["payment_items"] as! [[String: Any?]])
-      
+
     default:
       result(FlutterMethodNotImplemented)
     }

pay_ios/ios/pay_ios/Sources/pay_ios/PaymentHandler.swift

@@ -36,26 +36,30 @@ enum PaymentHandlerStatus {
 /// paymentHandler.canMakePayments(stringArguments)
 /// ```
 class PaymentHandler: NSObject {
-  
+
   /// Holds the current status of the payment process.
   var paymentHandlerStatus: PaymentHandlerStatus!
-  
+
   /// Stores a reference to the Flutter result while the operation completes.
   var paymentResult: FlutterResult!
-  
+
   /// Determines whether a user can make a payment with the selected provider.
   ///
   /// - parameter paymentConfiguration: A JSON string with the configuration to execute
   ///   this payment.
-  /// - returns: A boolean with the result: whether the use can make payments.
-  func canMakePayments(_ paymentConfiguration: String) -> Bool {
-    if let supportedNetworks = PaymentHandler.supportedNetworks(from: paymentConfiguration) {
+  /// - parameter existingPaymentMethodRequired: If true, requires a card; if false, only checks device support.
+  /// - returns: A boolean with the result: whether the user can make payments.
+  func canMakePayments(_ paymentConfiguration: String, existingPaymentMethodRequired: Bool = true) -> Bool {
+    if existingPaymentMethodRequired {
+      guard let supportedNetworks = PaymentHandler.supportedNetworks(from: paymentConfiguration) else {
+        return false
+      }
       return PKPaymentAuthorizationController.canMakePayments(usingNetworks: supportedNetworks)
-    } else {
-      return false
     }
+
+    return PKPaymentAuthorizationController.canMakePayments()
   }
-  
+
   /// Initiates the payment process with the selected payment provider.
   ///
   /// Calling this method starts the payment process and opens up the payment selector. Once the user
@@ -73,13 +77,13 @@ class PaymentHandler: NSObject {
 
     // Reset payment handler status
     paymentHandlerStatus = .started
-    
+
     // Deserialize payment configuration.
     guard let paymentRequest = PaymentHandler.createPaymentRequest(from: paymentConfiguration, paymentItems: paymentItems) else {
       result(FlutterError(code: "invalidPaymentConfiguration", message: "It was not possible to create a payment request from the provided configuration. Review your payment configuration and run again", details: nil))
       return
     }
-    
+
     // Display the payment selector with the request created.
     let paymentController = PKPaymentAuthorizationController(paymentRequest: paymentRequest)
     paymentController.delegate = self
@@ -91,7 +95,7 @@ class PaymentHandler: NSObject {
       }
     })
   }
-  
+
   /// Utility function to turn the payment configuration received through the method channel into a `Dictionary`.
   ///
   /// - parameter paymentConfigurationString: A JSON string with the configuration to execute
@@ -101,7 +105,7 @@ class PaymentHandler: NSObject {
     let paymentConfigurationData = paymentConfigurationString.data(using: .utf8)
     return try? JSONSerialization.jsonObject(with: paymentConfigurationData!) as? [String: Any]
   }
-  
+
   /// Extracts and parses the list of supported networks in the payment configuration.
   ///
   /// - parameter paymentConfigurationString: A JSON string with the configuration to execute
@@ -111,10 +115,10 @@ class PaymentHandler: NSObject {
     guard let paymentConfiguration = extractPaymentConfiguration(from: paymentConfigurationString) else {
       return nil
     }
-    
+
     return (paymentConfiguration["supportedNetworks"] as! [String]).compactMap { networkString in PKPaymentNetwork.fromString(networkString) }
   }
-  
+
   /// Creates a valid payment request for Apple Pay with the information included in the payment configuration.
   ///
   /// - parameter paymentConfigurationString: A JSON string with the configuration to execute
@@ -125,7 +129,7 @@ class PaymentHandler: NSObject {
     guard let paymentConfiguration = extractPaymentConfiguration(from: paymentConfigurationString) else {
       return nil
     }
-    
+
     // Create payment request and include summary items
     let paymentRequest = PKPaymentRequest()
     paymentRequest.paymentSummaryItems = paymentItems.map { item in
@@ -135,38 +139,38 @@ class PaymentHandler: NSObject {
         type: (PKPaymentSummaryItemType.fromString(item["status"] as? String ?? "final_price"))
       )
     }
-    
+
     // Configure the payment.
     paymentRequest.merchantIdentifier = paymentConfiguration["merchantIdentifier"] as! String
     paymentRequest.countryCode = paymentConfiguration["countryCode"] as! String
     paymentRequest.currencyCode = paymentConfiguration["currencyCode"] as! String
-    
+
     // Add merchant capabilities.
     if let merchantCapabilities = paymentConfiguration["merchantCapabilities"] as? Array<String> {
       paymentRequest.merchantCapabilities = PKMerchantCapability(merchantCapabilities.compactMap { capabilityString in
         PKMerchantCapability.fromString(capabilityString)
       })
     }
-    
+
     // Include the shipping fields required.
     if let requiredShippingFields = paymentConfiguration["requiredShippingContactFields"] as? Array<String> {
       paymentRequest.requiredShippingContactFields = Set(requiredShippingFields.compactMap { shippingField in
         PKContactField.fromString(shippingField)
       })
     }
-    
+
     // Include the billing fields required.
     if let requiredBillingFields = paymentConfiguration["requiredBillingContactFields"] as? Array<String> {
       paymentRequest.requiredBillingContactFields = Set(requiredBillingFields.compactMap { billingField in
         PKContactField.fromString(billingField)
       })
     }
-    
+
     // Add supported networks if available.
     if let supportedNetworks = supportedNetworks(from: paymentConfigurationString) {
       paymentRequest.supportedNetworks = supportedNetworks
     }
-    
+
     return paymentRequest
   }
 }
@@ -177,22 +181,22 @@ extension PaymentHandler: PKPaymentAuthorizationControllerDelegate {
   func paymentAuthorizationControllerWillAuthorizePayment(_ controller: PKPaymentAuthorizationController) {
       paymentHandlerStatus = .authorizationStarted
   }
-    
+
   func paymentAuthorizationController(_: PKPaymentAuthorizationController, didAuthorizePayment payment: PKPayment, handler completion: @escaping (PKPaymentAuthorizationResult) -> Void) {
-    
+
     // Collect payment result or error and return if no payment was selected
     guard let paymentResultData = try? JSONSerialization.data(withJSONObject: payment.toDictionary()) else {
       self.paymentResult(FlutterError(code: "paymentResultDeserializationFailed", message: nil, details: nil))
       return
     }
-    
+
     // Return the result back to the channel
     self.paymentResult(String(decoding: paymentResultData, as: UTF8.self))
-    
+
     paymentHandlerStatus = .authorized
     completion(PKPaymentAuthorizationResult(status: PKPaymentAuthorizationStatus.success, errors: nil))
   }
-  
+
   func paymentAuthorizationControllerDidFinish(_ controller: PKPaymentAuthorizationController) {
     controller.dismiss {
       DispatchQueue.main.async {

pay_platform_interface/lib/pay_channel.dart

@@ -41,10 +41,13 @@ class PayMethodChannel extends PayPlatform {
   /// Completes with a [PlatformException] if the native call fails or otherwise
   /// returns a boolean for the [paymentConfiguration] specified.
   @override
-  Future<bool> userCanPay(PaymentConfiguration paymentConfiguration) async {
+  Future<bool> userCanPay(PaymentConfiguration paymentConfiguration, {bool existingPaymentMethodRequired = false}) async {
     return await _channel.invokeMethod(
-            'userCanPay', jsonEncode(await paymentConfiguration.parameterMap()))
-        as bool;
+      'userCanPay', {
+        'paymentConfiguration': jsonEncode(await paymentConfiguration.parameterMap()),
+        'existingPaymentMethodRequired': existingPaymentMethodRequired,
+      },
+    ) as bool;
   }
 
   /// Shows the payment selector to complete the payment operation.

pay_platform_interface/lib/pay_platform_interface.dart

@@ -21,9 +21,10 @@ abstract class PayPlatform {
   /// Determines whether the caller can make a payment with a given
   /// configuration.
   ///
-  /// Returns a [Future] that resolves to a boolean value with the result based
-  /// on a given [paymentConfiguration].
-  Future<bool> userCanPay(PaymentConfiguration paymentConfiguration);
+  /// [existingPaymentMethodRequired]:
+  ///   - If true, only returns true if a supported payment method is available.
+  ///   - If false (default), returns true if the device and user support the payment method, even if none is currently available.
+  Future<bool> userCanPay(PaymentConfiguration paymentConfiguration, {bool existingPaymentMethodRequired = false});
 
   /// Triggers the action to show the payment selector to complete a payment
   /// with the configuration and a list of [PaymentItem] that help determine

pay_platform_interface/test/pay_channel_test.dart

@@ -60,7 +60,12 @@ void main() {
       await mobilePlatform.userCanPay(dummyConfig);
       expect(
         log,
-        <Matcher>[isMethodCall('userCanPay', arguments: '{}')],
+        <Matcher>[
+          isMethodCall('userCanPay', arguments: <String, Object>{
+            'paymentConfiguration': '{}',
+            'existingPaymentMethodRequired': false,
+          })
+        ],
       );
     });