Add prebuilt UI (PaymentSheet) functionality

CHANGELOG.md

@@ -4,6 +4,7 @@
 * [#3677](https://github.com/stripe/stripe-android/pull/3677) Upgrade Android Gradle Plugin to `4.2.0`
 * [#3680](https://github.com/stripe/stripe-android/pull/3680) Deprecate `returnUrl` in some `ConfirmPaymentIntentParams` create() methods
 * [#3685](https://github.com/stripe/stripe-android/pull/3685) Upgrade Kotlin to `1.5.0`
+* [#3687](https://github.com/stripe/stripe-android/pull/3687) Add support for PaymentSheet pre-built UI.
 
 ## 16.7.1 - 2021-04-29
 * [#3653](https://github.com/stripe/stripe-android/pull/3653) Support WeChat Pay for creating a `PaymentMethod` and confirming a `PaymentIntent`

example/build.gradle

@@ -3,6 +3,7 @@ plugins {
     id 'kotlin-android'
     id 'checkstyle'
     id 'org.jetbrains.kotlin.plugin.parcelize'
+    id 'org.jetbrains.kotlin.plugin.serialization' version '1.4.30'
 }
 
 assemble.dependsOn('lint')
@@ -69,13 +70,15 @@ dependencies {
     /* Used to make Retrofit easier and GSON & Rx-compatible*/
     implementation 'com.google.code.gson:gson:2.8.6'
     implementation "com.squareup.retrofit2:converter-gson:$retrofitVersion"
+    implementation "com.jakewharton.retrofit:retrofit2-kotlinx-serialization-converter:0.8.0"
 
     implementation 'com.squareup.okhttp3:logging-interceptor:4.9.1'
 
     debugImplementation 'com.squareup.leakcanary:leakcanary-android:2.7'
 
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$kotlinCoroutinesVersion"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$kotlinCoroutinesVersion"
+    implementation "org.jetbrains.kotlinx:kotlinx-serialization-json:1.1.0"
 
     ktlint "com.pinterest:ktlint:$ktlintVersion"
 

example/res/menu/payment_sheet.xml

@@ -2,13 +2,6 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
       xmlns:app="http://schemas.android.com/apk/res-auto">
 
-    <item
-        android:id="@+id/refresh_key"
-        android:orderInCategory="300"
-        android:title="Refresh Ephemeral Key"
-        android:icon="@drawable/ic_refresh"
-        app:showAsAction="ifRoom" />
-
     <item
         android:id="@+id/config"
         android:orderInCategory="300"

example/res/menu/payment_sheet_custom.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <item
+        android:id="@+id/refresh_key"
+        android:orderInCategory="300"
+        android:title="Refresh"
+        android:icon="@drawable/ic_refresh"
+        app:showAsAction="ifRoom" />
+
+    <item
+        android:id="@+id/config"
+        android:orderInCategory="300"
+        android:title="Configure Payment Sheet"
+        android:icon="@drawable/ic_settings"
+        app:showAsAction="ifRoom" />
+</menu>

example/res/xml/payment_sheet_preferences.xml

@@ -13,6 +13,11 @@
         app:title="Use Customer API"
         app:defaultValue="true" />
 
+    <SwitchPreferenceCompat
+        app:key="returning_customer"
+        app:title="Returning Customer"
+        app:defaultValue="true" />
+
     <SwitchPreferenceCompat
         app:key="enable_googlepay"
         app:title="Enable Google Pay"

example/src/main/java/com/stripe/example/Settings.kt

@@ -36,7 +36,7 @@ class Settings(context: Context) {
             .takeIf { it?.isNotBlank() == true }
     }
 
-    private companion object {
+    internal companion object {
         /**
          * Note: only necessary if not configured via `gradle.properties`.
          *
@@ -62,6 +62,13 @@ class Settings(context: Context) {
          */
         private val STRIPE_ACCOUNT_ID: String? = null
 
+        // Example payment sheet backend with a "/checkout" endpoint
+        // Remix from https://glitch.com/edit/#!/stripe-mobile-payment-sheet-test-playground-v3
+        internal const val PAYMENT_SHEET_BASE_URL = ""
+
+        // Publishable key for example payment sheet backend
+        internal const val PAYMENT_SHEET_PUBLISHABLE_KEY = ""
+
         private const val METADATA_KEY_BACKEND_URL_KEY =
             "com.stripe.example.metadata.backend_url"
         private const val METADATA_KEY_PUBLISHABLE_KEY =

example/src/main/java/com/stripe/example/activity/BasePaymentSheetActivity.kt

@@ -1,12 +1,12 @@
 package com.stripe.example.activity
 
-import android.content.Context
 import android.content.SharedPreferences
 import android.view.Menu
 import android.view.MenuItem
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import androidx.preference.PreferenceManager
+import com.stripe.android.PaymentConfiguration
 import com.stripe.android.paymentsheet.PaymentSheet
 import com.stripe.android.paymentsheet.PaymentSheetResult
 import com.stripe.example.R
@@ -15,8 +15,7 @@ import com.stripe.example.paymentsheet.PaymentSheetViewModel
 internal abstract class BasePaymentSheetActivity : AppCompatActivity() {
     protected val viewModel: PaymentSheetViewModel by viewModels {
         PaymentSheetViewModel.Factory(
-            application,
-            getPreferences(Context.MODE_PRIVATE)
+            application
         )
     }
 
@@ -30,6 +29,9 @@ internal abstract class BasePaymentSheetActivity : AppCompatActivity() {
     protected val isCustomerEnabled: Boolean
         get() = prefsManager.getBoolean("enable_customer", true)
 
+    protected val isReturningCustomer: Boolean
+        get() = prefsManager.getBoolean("returning_customer", true)
+
     protected val isSetupIntent: Boolean
         get() = prefsManager.getBoolean("setup_intent", false)
 
@@ -46,6 +48,20 @@ internal abstract class BasePaymentSheetActivity : AppCompatActivity() {
             }
         }
 
+    protected val customer: String
+        get() = if (isCustomerEnabled && isReturningCustomer) {
+            "returning"
+        } else if (isCustomerEnabled) {
+            temporaryCustomerId ?: "new"
+        } else {
+            "new"
+        }
+
+    protected val mode: String
+        get() = if (isSetupIntent) "setup" else "payment"
+
+    protected var temporaryCustomerId: String? = null
+
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
         // Inflate the menu; this adds items to the action bar if it is present.
         menuInflater.inflate(R.menu.payment_sheet, menu)
@@ -59,44 +75,41 @@ internal abstract class BasePaymentSheetActivity : AppCompatActivity() {
                 PaymentSheetConfigBottomSheet.TAG
             )
             return true
-        } else if (item.itemId == R.id.refresh_key) {
-            viewModel.clearKeys()
-            onRefreshEphemeralKey()
         }
+
         return super.onOptionsItemSelected(item)
     }
 
-    protected fun fetchEphemeralKey(
-        onSuccess: (PaymentSheet.CustomerConfiguration) -> Unit = {}
+    protected fun prepareCheckout(
+        onSuccess: (PaymentSheet.CustomerConfiguration, String) -> Unit
     ) {
-        viewModel.fetchEphemeralKey()
-            .observe(this) { newEphemeralKey ->
-                if (newEphemeralKey != null) {
+        viewModel.prepareCheckout(customer, mode)
+            .observe(this) { checkoutResponse ->
+                if (checkoutResponse != null) {
+                    temporaryCustomerId = if (isCustomerEnabled && !isReturningCustomer) {
+                        checkoutResponse.customerId
+                    } else {
+                        null
+                    }
+
+                    // Re-initing here because the ExampleApplication inits with the key from
+                    // gradle properties
+                    PaymentConfiguration.init(this, checkoutResponse.publishableKey)
+
                     onSuccess(
                         PaymentSheet.CustomerConfiguration(
-                            id = newEphemeralKey.customer,
-                            ephemeralKeySecret = newEphemeralKey.key
-                        )
+                            id = checkoutResponse.customerId,
+                            ephemeralKeySecret = checkoutResponse.customerEphemeralKeySecret
+                        ),
+                        checkoutResponse.intentClientSecret
                     )
                 }
             }
     }
 
-    protected fun onPaymentSheetResult(
+    protected open fun onPaymentSheetResult(
         paymentResult: PaymentSheetResult
     ) {
         viewModel.status.value = paymentResult.toString()
     }
-
-    protected fun onError(error: Throwable) {
-        viewModel.status.postValue(
-            """
-            ${viewModel.status.value}
-
-            Failed: ${error.message}
-            """.trimIndent()
-        )
-    }
-
-    abstract fun onRefreshEphemeralKey()
 }

example/src/main/java/com/stripe/example/activity/LaunchPaymentSheetCompleteActivity.kt

@@ -1,7 +1,7 @@
 package com.stripe.example.activity
 
 import android.os.Bundle
-import android.view.View
+import androidx.core.view.isInvisible
 import com.stripe.android.paymentsheet.PaymentSheet
 import com.stripe.example.databinding.ActivityPaymentSheetCompleteBinding
 
@@ -14,66 +14,39 @@ internal class LaunchPaymentSheetCompleteActivity : BasePaymentSheetActivity() {
         super.onCreate(savedInstanceState)
         setContentView(viewBinding.root)
 
+        val paymentSheet = PaymentSheet(this, ::onPaymentSheetResult)
+
         viewModel.inProgress.observe(this) {
-            viewBinding.progressBar.visibility = if (it) View.VISIBLE else View.INVISIBLE
+            viewBinding.progressBar.isInvisible = !it
             viewBinding.launch.isEnabled = !it
         }
+
         viewModel.status.observe(this) {
             viewBinding.status.text = it
         }
 
         viewBinding.launch.setOnClickListener {
-            if (isCustomerEnabled) {
-                fetchEphemeralKey { customerConfig ->
-                    createPaymentIntent(
-                        customerConfig
+            prepareCheckout { customerConfig, clientSecret ->
+                if (isSetupIntent) {
+                    paymentSheet.presentWithSetupIntent(
+                        clientSecret,
+                        PaymentSheet.Configuration(
+                            merchantDisplayName = merchantName,
+                            customer = customerConfig,
+                            googlePay = googlePayConfig,
+                        )
                     )
-                }
-            } else {
-                createPaymentIntent(
-                    null
-                )
-            }
-        }
-
-        fetchEphemeralKey()
-    }
-
-    private fun createPaymentIntent(
-        customerConfig: PaymentSheet.CustomerConfiguration?
-    ) {
-        viewModel.createPaymentIntent(
-            COUNTRY_CODE,
-            customerId = customerConfig?.id
-        ).observe(this) { result ->
-            result.fold(
-                onSuccess = { json ->
-                    val clientSecret = json.getString("secret")
-
-                    onPaymentIntent(
+                } else {
+                    paymentSheet.presentWithPaymentIntent(
                         clientSecret,
-                        customerConfig
+                        PaymentSheet.Configuration(
+                            merchantDisplayName = merchantName,
+                            customer = customerConfig,
+                            googlePay = googlePayConfig,
+                        )
                     )
-                },
-                onFailure = ::onError
-            )
+                }
+            }
         }
     }
-
-    private fun onPaymentIntent(
-        paymentIntentClientSecret: String,
-        customerConfig: PaymentSheet.CustomerConfiguration?
-    ) {
-        viewModel.inProgress.postValue(false)
-
-        // show PaymentSheet
-    }
-
-    override fun onRefreshEphemeralKey() {
-        fetchEphemeralKey()
-    }
-
-    private companion object {
-        private const val COUNTRY_CODE = "us"
-    }
 }