Merge pull request #51 from qonversion/feature/deferredPurchasesStream

Feature/deferred purchases stream

Author: Maria-Bordunova

android/src/main/kotlin/com/qonversion/flutter/sdk/qonversion_flutter_sdk/BaseEventStreamHandler.kt

@@ -0,0 +1,15 @@
+package com.qonversion.flutter.sdk.qonversion_flutter_sdk
+
+import io.flutter.plugin.common.EventChannel
+
+class BaseEventStreamHandler : EventChannel.StreamHandler {
+    var eventSink: EventChannel.EventSink? = null
+
+    override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
+        eventSink = events
+    }
+
+    override fun onCancel(arguments: Any?) {
+        eventSink = null
+    }
+}

android/src/main/kotlin/com/qonversion/flutter/sdk/qonversion_flutter_sdk/BaseListenerWrapper.kt

@@ -0,0 +1,29 @@
+package com.qonversion.flutter.sdk.qonversion_flutter_sdk
+
+import io.flutter.plugin.common.BinaryMessenger
+import io.flutter.plugin.common.EventChannel
+
+abstract class BaseListenerWrapper(
+        val binaryMessenger: BinaryMessenger
+) {
+
+    protected abstract val eventChannelPostfix: String
+
+    protected var eventChannel: EventChannel? = null
+    protected var eventStreamHandler: BaseEventStreamHandler? = null
+
+    fun register() {
+        eventStreamHandler =
+                BaseEventStreamHandler()
+        eventChannel = EventChannel(
+                binaryMessenger,
+                "qonversion_flutter_${eventChannelPostfix}"
+        ).apply { setStreamHandler(eventStreamHandler) }
+    }
+
+    fun unregister() {
+        eventChannel?.setStreamHandler(null)
+        eventStreamHandler = null
+        eventChannel = null
+    }
+}

android/src/main/kotlin/com/qonversion/flutter/sdk/qonversion_flutter_sdk/QonversionFlutterSdkPlugin.kt

@@ -18,15 +18,21 @@ import com.qonversion.android.sdk.dto.offerings.QOfferings
 import com.qonversion.android.sdk.dto.products.QProduct
 
 /** QonversionFlutterSdkPlugin */
-class QonversionFlutterSdkPlugin internal constructor(registrar: Registrar): MethodCallHandler {
+class QonversionFlutterSdkPlugin internal constructor(registrar: Registrar): MethodCallHandler, BaseListenerWrapper(registrar.messenger()) {
     private val activity: Activity = registrar.activity()
     private val application: Application = activity.application
 
+    override val eventChannelPostfix = "updated_purchases"
+
     companion object {
         @JvmStatic
         fun registerWith(registrar: Registrar) {
             val channel = MethodChannel(registrar.messenger(), "qonversion_flutter_sdk")
-            channel.setMethodCallHandler(QonversionFlutterSdkPlugin(registrar))
+            val instance = QonversionFlutterSdkPlugin(registrar)
+            channel.setMethodCallHandler(instance)
+
+            // Register Updated Purchases Event Channel
+            instance.register()
         }
     }
 
@@ -91,6 +97,18 @@ class QonversionFlutterSdkPlugin internal constructor(registrar: Registrar): Met
                     }
                 }
         )
+
+        startListeningPendingPurchasesEvents()
+    }
+
+    private fun startListeningPendingPurchasesEvents() {
+        Qonversion.setUpdatedPurchasesListener(object : UpdatedPurchasesListener {
+            override fun onPermissionsUpdate(permissions: Map<String, QPermission>) {
+                val payload = Gson().toJson(permissions.mapValues { it.value.toMap() })
+
+                eventStreamHandler?.eventSink?.success(payload)
+            }
+        })
     }
 
     private fun purchase(productId: String?, result: Result) {

example/lib/products_view.dart

@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:flutter/material.dart';
 import 'package:qonversion_flutter/qonversion_flutter.dart';
 
@@ -9,12 +11,23 @@ class ProductsView extends StatefulWidget {
 class _ProductsViewState extends State<ProductsView> {
   var _products = <String, QProduct>{};
   QOfferings _offerings;
+  StreamSubscription<Map<String, QPermission>> _subscription;
 
   @override
   void initState() {
     super.initState();
     _loadProducts();
     _loadOfferings();
+
+    _subscription =
+        Qonversion.updatedPurchasesStream.listen((event) => print(event));
+  }
+
+  @override
+  void dispose() {
+    _subscription.cancel();
+
+    super.dispose();
   }
 
   @override

ios/Classes/BaseEventStreamHandler.swift

@@ -0,0 +1,24 @@
+//
+//  BaseEventStreamHandler.swift
+//  qonversion_flutter
+//
+//  Created by Ilya Virnik on 2/7/21.
+//
+
+import Flutter
+
+protocol EventStreamHandler: NSObject, FlutterStreamHandler {}
+
+class BaseEventStreamHandler: NSObject, EventStreamHandler {
+  var eventSink: FlutterEventSink?
+  
+  public func onListen(withArguments arguments: Any?, eventSink events: @escaping FlutterEventSink) -> FlutterError? {
+    eventSink = events
+    return nil
+  }
+  
+  public func onCancel(withArguments arguments: Any?) -> FlutterError? {
+    eventSink = nil
+    return nil
+  }
+}

ios/Classes/BaseListenerWrapper.swift

@@ -0,0 +1,48 @@
+//
+//  BaseListenerWrapper.swift
+//  qonversion_flutter
+//
+//  Created by Ilya Virnik on 2/7/21.
+//
+
+import Flutter
+
+typealias MethodCodec = NSObject & FlutterMethodCodec
+
+class FlutterListenerWrapper<T>: NSObject where T: EventStreamHandler {
+  let binding: FlutterPluginRegistrar
+  let eventChannelPostfix: String
+  
+  var eventChannel: FlutterEventChannel?
+  var eventStreamHandler: T?
+  
+  init(_ binding: FlutterPluginRegistrar, postfix: String) {
+    self.binding = binding
+    self.eventChannelPostfix = postfix
+  }
+  
+  func register(_ codec: MethodCodec? = nil, completion: ((T?) -> Void)? = nil) {
+    guard eventStreamHandler == nil else {
+      return
+    }
+    eventStreamHandler = T()
+    if let codec = codec {
+      eventChannel = FlutterEventChannel(name: "qonversion_flutter_\(eventChannelPostfix)",
+                                         binaryMessenger: binding.messenger(),
+                                         codec: codec)
+    } else {
+      eventChannel = FlutterEventChannel(name: "qonversion_flutter_\(eventChannelPostfix)",
+                                         binaryMessenger: binding.messenger())
+    }
+    
+    eventChannel?.setStreamHandler(eventStreamHandler)
+    
+    completion?(eventStreamHandler)
+  }
+  
+  func unregister() {
+    eventChannel?.setStreamHandler(nil)
+    eventStreamHandler = nil
+    eventChannel = nil
+  }
+}

ios/Classes/SwiftQonversionFlutterSdkPlugin.swift

@@ -3,10 +3,19 @@ import UIKit
 import Qonversion
 
 public class SwiftQonversionFlutterSdkPlugin: NSObject, FlutterPlugin {
+  var purchasesEventStreamHandler: BaseEventStreamHandler?
+  
   public static func register(with registrar: FlutterPluginRegistrar) {
     let channel = FlutterMethodChannel(name: "qonversion_flutter_sdk", binaryMessenger: registrar.messenger())
     let instance = SwiftQonversionFlutterSdkPlugin()
     registrar.addMethodCallDelegate(instance, channel: channel)
+    
+    // Register events listeners
+    let purchasesListener = FlutterListenerWrapper<BaseEventStreamHandler>(registrar, postfix: "updated_purchases")
+    purchasesListener.register() { instance.purchasesEventStreamHandler = $0 }
+    
+    // Setting delegate as soon as plugin is registered
+    Qonversion.setPurchasesDelegate(instance)
   }
 
   public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
@@ -227,3 +236,11 @@ public class SwiftQonversionFlutterSdkPlugin: NSObject, FlutterPlugin {
     result(nil)
   }
 }
+
+extension SwiftQonversionFlutterSdkPlugin: Qonversion.PurchasesDelegate {
+  public func qonversionDidReceiveUpdatedPermissions(_ permissions: [String : Qonversion.Permission]) {
+    let payload = permissions.mapValues { $0.toMap() }.toJson()
+    
+    purchasesEventStreamHandler?.eventSink?(payload)
+  }
+}

lib/src/qonversion.dart

@@ -17,6 +17,20 @@ import 'qa_provider.dart';
 
 class Qonversion {
   static const MethodChannel _channel = MethodChannel('qonversion_flutter_sdk');
+  static const _purchasesEventChannel =
+      EventChannel('qonversion_flutter_updated_purchases');
+
+  /// Yields an event each time a deferred transaction happens
+  static Stream<Map<String, QPermission>> get updatedPurchasesStream =>
+      _purchasesEventChannel
+          .receiveBroadcastStream()
+          .cast<String>()
+          .map((event) {
+        final Map<String, dynamic> decodedEvent = jsonDecode(event);
+
+        return decodedEvent
+            .map((key, value) => MapEntry(key, QPermission.fromJson(value)));
+      });
 
   /// Initializes Qonversion SDK with the given API key.
   /// You can get one in your account on qonversion.io.
@@ -169,9 +183,18 @@ class Qonversion {
     return _channel.invokeMethod(Constants.mAddAttributionData, args);
   }
 
+  /// You can set the flag to distinguish sandbox and production users.
+  /// To see the sandbox users turn on the Viewing test Data toggle on Qonversion Dashboard
   static Future<void> setDebugMode() =>
       _channel.invokeMethod(Constants.mSetDebugMode);
 
+  /// Return Qonversion Offerings Object
+  /// An offering is a group of products that you can offer to a user on a given paywall based on your business logic.
+  /// For example, you can offer one set of products on a paywall immediately after onboarding and another set of products with discounts later on if a user has not converted.
+  /// Offerings allow changing the products offered remotely without releasing app updates.
+  ///
+  /// See [Offerings](https://qonversion.io/docs/offerings) for more details.
+  /// See [Product Center](https://qonversion.io/docs/product-center) for more details.
   static Future<QOfferings> offerings() async {
     final offeringsString =
         await _channel.invokeMethod<String>(Constants.mOfferings);
@@ -181,6 +204,9 @@ class Qonversion {
     return QOfferings.fromJson(decodedOfferings);
   }
 
+  /// You can check if a user is eligible for an introductory offer, including a free trial.
+  /// You can show only a regular price for users who are not eligible for an introductory offer.
+  /// [ids] products identifiers that must be checked
   static Future<Map<String, QEligibility>> checkTrialIntroEligibility(
       List<String> ids) async {
     final eligibilitiesString = await _channel.invokeMethod<String>(