[DO NOT MERGE]: V3 Proof of Concept – SessionStore

CorePayments/build.gradle

@@ -68,6 +68,7 @@ dependencies {
     implementation libs.androidx.appcompat
     implementation libs.kotlin.stdLib
     implementation libs.kotlinx.coroutinesAndroid
+    implementation libs.androidx.browser
 
     testImplementation libs.json
     testImplementation libs.jsonAssert

CorePayments/src/main/java/com/paypal/android/corepayments/ChromeCustomTabsResult.kt

@@ -0,0 +1,5 @@
+package com.paypal.android.corepayments
+
+import android.content.Intent
+
+data class ChromeCustomTabsResult(val resultCode: Int, val intent: Intent?)

CorePayments/src/main/java/com/paypal/android/corepayments/LaunchChromeCustomTab.kt

@@ -0,0 +1,20 @@
+package com.paypal.android.corepayments
+
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import androidx.activity.result.contract.ActivityResultContract
+import androidx.browser.customtabs.CustomTabsIntent
+
+// Ref: https://developer.android.com/training/basics/intents/result#custom
+class LaunchChromeCustomTab : ActivityResultContract<Uri, ChromeCustomTabsResult>() {
+    override fun createIntent(context: Context, input: Uri): Intent {
+        val customTabsIntent = CustomTabsIntent.Builder().build()
+        val intent = customTabsIntent.intent
+        intent.data = input
+        return intent
+    }
+
+    override fun parseResult(resultCode: Int, intent: Intent?)
+        = ChromeCustomTabsResult(resultCode = resultCode, intent = intent)
+}

CorePayments/src/main/java/com/paypal/android/corepayments/MapUtils.kt

@@ -0,0 +1,27 @@
+package com.paypal.android.corepayments
+
+import android.util.Base64
+import androidx.annotation.RestrictTo
+import org.json.JSONObject
+import java.nio.charset.StandardCharsets
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+fun MutableMap<String, String?>.restoreFromBase64EncodedJSON(base64EncodedJSON: String) {
+    clear()
+
+    val data = Base64.decode(base64EncodedJSON, Base64.DEFAULT)
+    val requestJSONString = String(data, StandardCharsets.UTF_8)
+    val requestJSON = JSONObject(requestJSONString)
+    val properties = mutableMapOf<String, Any>().apply {
+        requestJSON.keys().forEach { put(it, requestJSON[it]) }
+    }
+    properties.putAll(properties)
+}
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+fun MutableMap<String, String?>.toBase64EncodedJSON(): String {
+    val propertiesAsJSON = JSONObject(this)
+    val requestJSONBytes: ByteArray? =
+        propertiesAsJSON.toString().toByteArray(StandardCharsets.UTF_8)
+    return Base64.encodeToString(requestJSONBytes, Base64.DEFAULT)
+}

CorePayments/src/main/java/com/paypal/android/corepayments/SessionStore.kt

@@ -0,0 +1,14 @@
+package com.paypal.android.corepayments
+
+import androidx.annotation.RestrictTo
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+open class SessionStore {
+    val properties: MutableMap<String, String?> = mutableMapOf()
+
+    fun clear() = properties.clear()
+    fun restore(base64EncodedJSON: String) =
+        properties.restoreFromBase64EncodedJSON(base64EncodedJSON)
+
+    fun toBase64EncodedJSON() = properties.toBase64EncodedJSON()
+}

Demo/build.gradle

@@ -113,6 +113,7 @@ dependencies {
     implementation libs.androidx.constraintLayout
     implementation libs.lifecycle.runtimeKtx
     implementation libs.androidx.fragmentKtx
+    implementation libs.androidx.activity.compose
 
     // Compose Bill of Materials (BOM) dependency manages compose dependency versions without
     // us having to explicitly state versions of individual compose dependencies; the BOM project

Demo/src/main/java/com/paypal/android/ui/paypalweb/PayPalWebView.kt

@@ -1,5 +1,6 @@
 package com.paypal.android.ui.paypalweb
 
+import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
@@ -13,11 +14,13 @@ import androidx.compose.material3.Surface
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.paypal.android.corepayments.LaunchChromeCustomTab
 import com.paypal.android.uishared.components.ActionButtonColumn
 import com.paypal.android.uishared.components.CreateOrderForm
 import com.paypal.android.uishared.components.ErrorView
@@ -28,6 +31,7 @@ import com.paypal.android.utils.OnLifecycleOwnerResumeEffect
 import com.paypal.android.utils.OnNewIntentEffect
 import com.paypal.android.utils.UIConstants
 import com.paypal.android.utils.getActivityOrNull
+import kotlinx.coroutines.launch
 
 @Composable
 fun PayPalWebView(
@@ -50,6 +54,14 @@ fun PayPalWebView(
         viewModel.completeAuthChallenge(newIntent)
     }
 
+    // Ref: https://stackoverflow.com/a/67156998
+    val coroutineScope = rememberCoroutineScope()
+    val chromeCustomTabsLauncher =
+        rememberLauncherForActivityResult(LaunchChromeCustomTab()) { result ->
+            // forward result from activity launcher
+            viewModel.completeAuthChallenge(result)
+        }
+
     val contentPadding = UIConstants.paddingMedium
     Column(
         verticalArrangement = UIConstants.spacingLarge,
@@ -60,7 +72,17 @@ fun PayPalWebView(
     ) {
         Step1_CreateOrder(uiState, viewModel)
         if (uiState.isCreateOrderSuccessful) {
-            Step2_StartPayPalWebCheckout(uiState, viewModel)
+            Step2_StartPayPalWebCheckout(
+                uiState = uiState,
+                viewModel = viewModel,
+                onPayPalCheckoutInitiated = {
+                    coroutineScope.launch {
+                        viewModel.startWebCheckout()?.let { uri ->
+                            chromeCustomTabsLauncher.launch(uri)
+                        }
+                    }
+                }
+            )
         }
         if (uiState.isPayPalWebCheckoutSuccessful) {
             Step3_CompleteOrder(uiState, viewModel)
@@ -96,8 +118,11 @@ private fun Step1_CreateOrder(uiState: PayPalWebUiState, viewModel: PayPalWebVie
 }
 
 @Composable
-private fun Step2_StartPayPalWebCheckout(uiState: PayPalWebUiState, viewModel: PayPalWebViewModel) {
-    val context = LocalContext.current
+private fun Step2_StartPayPalWebCheckout(
+    uiState: PayPalWebUiState,
+    viewModel: PayPalWebViewModel,
+    onPayPalCheckoutInitiated: () -> Unit
+) {
     Column(
         verticalArrangement = UIConstants.spacingMedium,
     ) {
@@ -110,7 +135,7 @@ private fun Step2_StartPayPalWebCheckout(uiState: PayPalWebUiState, viewModel: P
             defaultTitle = "START CHECKOUT",
             successTitle = "CHECKOUT COMPLETE",
             state = uiState.payPalWebCheckoutState,
-            onClick = { context.getActivityOrNull()?.let { viewModel.startWebCheckout(it) } },
+            onClick = onPayPalCheckoutInitiated,
             modifier = Modifier
                 .fillMaxWidth()
         ) { state ->

Demo/src/main/java/com/paypal/android/ui/paypalweb/PayPalWebViewModel.kt

@@ -2,13 +2,16 @@ package com.paypal.android.ui.paypalweb
 
 import android.content.Context
 import android.content.Intent
+import android.net.Uri
+import android.os.Bundle
 import android.util.Log
-import androidx.activity.ComponentActivity
+import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.paypal.android.api.model.Order
 import com.paypal.android.api.model.OrderIntent
 import com.paypal.android.api.services.SDKSampleServerResult
+import com.paypal.android.corepayments.ChromeCustomTabsResult
 import com.paypal.android.corepayments.CoreConfig
 import com.paypal.android.fraudprotection.PayPalDataCollector
 import com.paypal.android.fraudprotection.PayPalDataCollectorRequest
@@ -23,6 +26,7 @@ import com.paypal.android.usecase.CompleteOrderUseCase
 import com.paypal.android.usecase.CreateOrderUseCase
 import com.paypal.android.usecase.GetClientIdUseCase
 import dagger.hilt.android.lifecycle.HiltViewModel
+import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
@@ -31,9 +35,11 @@ import javax.inject.Inject
 
 @HiltViewModel
 class PayPalWebViewModel @Inject constructor(
+    @ApplicationContext val applicationContext: Context,
     val getClientIdUseCase: GetClientIdUseCase,
     val createOrderUseCase: CreateOrderUseCase,
-    val completeOrderUseCase: CompleteOrderUseCase
+    val completeOrderUseCase: CompleteOrderUseCase,
+    private val savedStateHandle: SavedStateHandle
 ) : ViewModel() {
 
     companion object {
@@ -46,7 +52,9 @@ class PayPalWebViewModel @Inject constructor(
     private val _uiState = MutableStateFlow(PayPalWebUiState())
     val uiState = _uiState.asStateFlow()
 
-    private var authState: String? = null
+    init {
+        registerPayPalWebCheckoutClientSaveInstanceStateHandler()
+    }
 
     var intentOption: OrderIntent
         get() = _uiState.value.intentOption
@@ -81,6 +89,28 @@ class PayPalWebViewModel @Inject constructor(
             _uiState.update { it.copy(fundingSource = value) }
         }
 
+    private fun registerPayPalWebCheckoutClientSaveInstanceStateHandler() {
+        savedStateHandle.setSavedStateProvider("pay_pal_web_view_model") {
+            val bundle = Bundle()
+            paypalClient?.instanceState?.let { instanceState ->
+                bundle.putString("instance_state", instanceState)
+            }
+            bundle
+        }
+    }
+
+    private fun restorePayPalWebCheckoutClientFromSavedInstanceState() {
+        // restore instance state
+        val savedStateBundle = savedStateHandle.get<Bundle>("pay_pal_web_view_model")
+        savedStateBundle?.let { bundle ->
+            bundle.getString("instance_state")?.let { instanceState ->
+                paypalClient?.restore(instanceState)
+            }
+        }
+        // make sure saved instance state is only restored once
+        savedStateHandle.remove<Bundle>("pay_pal_web_view_model")
+    }
+
     fun createOrder() {
         viewModelScope.launch {
             createOrderState = ActionState.Loading
@@ -91,18 +121,17 @@ class PayPalWebViewModel @Inject constructor(
         }
     }
 
-    fun startWebCheckout(activity: ComponentActivity) {
+    suspend fun startWebCheckout(): Uri? {
         val orderId = createdOrder?.id
         if (orderId == null) {
             payPalWebCheckoutState = ActionState.Failure(Exception("Create an order to continue."))
         } else {
-            viewModelScope.launch {
-                startWebCheckoutWithOrderId(activity, orderId)
-            }
+            return startWebCheckoutWithOrderId(orderId)
         }
+        return null
     }
 
-    private suspend fun startWebCheckoutWithOrderId(activity: ComponentActivity, orderId: String) {
+    private suspend fun startWebCheckoutWithOrderId(orderId: String): Uri? {
         payPalWebCheckoutState = ActionState.Loading
 
         when (val clientIdResult = getClientIdUseCase()) {
@@ -115,12 +144,14 @@ class PayPalWebViewModel @Inject constructor(
                 payPalDataCollector = PayPalDataCollector(coreConfig)
 
                 paypalClient =
-                    PayPalWebCheckoutClient(activity, coreConfig, "com.paypal.android.demo")
+                    PayPalWebCheckoutClient(applicationContext, coreConfig, "com.paypal.android.demo")
+                restorePayPalWebCheckoutClientFromSavedInstanceState()
 
                 val checkoutRequest = PayPalWebCheckoutRequest(orderId, fundingSource)
-                when (val startResult = paypalClient?.start(activity, checkoutRequest)) {
-                    is PayPalPresentAuthChallengeResult.Success ->
-                        authState = startResult.authState
+                when (val startResult = paypalClient?.start(checkoutRequest)) {
+                    is PayPalPresentAuthChallengeResult.Success -> {
+                        return startResult.uri
+                    }
 
                     is PayPalPresentAuthChallengeResult.Failure ->
                         payPalWebCheckoutState = ActionState.Failure(startResult.error)
@@ -131,6 +162,7 @@ class PayPalWebViewModel @Inject constructor(
                 }
             }
         }
+        return null
     }
 
     fun completeOrder(context: Context) {
@@ -150,26 +182,23 @@ class PayPalWebViewModel @Inject constructor(
     }
 
     private fun checkIfPayPalAuthFinished(intent: Intent): PayPalWebCheckoutFinishStartResult? =
-        authState?.let { paypalClient?.finishStart(intent, it) }
+         paypalClient?.finishStart(intent)
 
     fun completeAuthChallenge(intent: Intent) {
         checkIfPayPalAuthFinished(intent)?.let { payPalAuthResult ->
             when (payPalAuthResult) {
                 is PayPalWebCheckoutFinishStartResult.Success -> {
                     payPalWebCheckoutState = ActionState.Success(payPalAuthResult)
-                    discardAuthState()
                 }
 
                 is PayPalWebCheckoutFinishStartResult.Canceled -> {
                     val error = Exception("USER CANCELED")
                     payPalWebCheckoutState = ActionState.Failure(error)
-                    discardAuthState()
                 }
 
                 is PayPalWebCheckoutFinishStartResult.Failure -> {
                     Log.i(TAG, "Checkout Error: ${payPalAuthResult.error.errorDescription}")
                     payPalWebCheckoutState = ActionState.Failure(payPalAuthResult.error)
-                    discardAuthState()
                 }
 
                 PayPalWebCheckoutFinishStartResult.NoResult -> {
@@ -180,7 +209,11 @@ class PayPalWebViewModel @Inject constructor(
         }
     }
 
-    private fun discardAuthState() {
-        authState = null
+    fun completeAuthChallenge(chromeCustomTabsResult: ChromeCustomTabsResult) {
+//        if (chromeCustomTabsResult.resultCode == Activity.RESULT_CANCELED) {
+//            val error = Exception("USER CANCELED")
+//            payPalWebCheckoutState = ActionState.Failure(error)
+//            discardAuthState()
+//        }
     }
 }