Add Client Metadata Id Accessor to DropInClient

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Braintree Android Drop-In Release Notes
 
+## unreleased
+
+* Add `DropInClient#getClientMetadataId()` method
+
 ## 6.5.1
 
 * Fix issue that caused Add Card button to attempt tokenization multiple times when double tapped.

Drop-In/build.gradle

@@ -84,6 +84,8 @@ dependencies {
 
     api 'com.braintreepayments:card-form:5.4.0'
 
+    implementation deps.payPalDataCollector
+
     implementation 'androidx.cardview:cardview:1.0.0'
     implementation 'com.google.android.gms:play-services-wallet:16.0.0'
     implementation 'androidx.recyclerview:recyclerview:1.2.1'

Drop-In/src/main/java/com/braintreepayments/api/DropInClient.java

@@ -29,9 +29,10 @@ public class DropInClient {
     private final GooglePayClient googlePayClient;
 
     private final DropInRequest dropInRequest;
-
     private final DropInSharedPreferences dropInSharedPreferences;
 
+    private final PayPalDataCollector payPalDataCollector;
+
     private DropInListener listener;
 
     @VisibleForTesting
@@ -51,6 +52,7 @@ private static DropInClientParams createDefaultParams(Context context, String au
                 .lifecycle(lifecycle)
                 .dropInRequest(dropInRequest)
                 .braintreeClient(braintreeClient)
+                .payPalDataCollector(new PayPalDataCollector(braintreeClient))
                 .paymentMethodClient(new PaymentMethodClient(braintreeClient))
                 .googlePayClient(new GooglePayClient(braintreeClient))
                 .dropInSharedPreferences(DropInSharedPreferences.getInstance(context.getApplicationContext()));
@@ -172,6 +174,7 @@ public DropInClient(Fragment fragment, ClientTokenProvider clientTokenProvider)
         this.googlePayClient = params.getGooglePayClient();
         this.paymentMethodClient = params.getPaymentMethodClient();
         this.dropInSharedPreferences = params.getDropInSharedPreferences();
+        this.payPalDataCollector = params.getPayPalDataCollector();
 
         FragmentActivity activity = params.getActivity();
         Lifecycle lifecycle = params.getLifecycle();
@@ -369,4 +372,27 @@ void onDropInResult(DropInResult dropInResult) {
     public void invalidateClientToken() {
         braintreeClient.invalidateClientToken();
     }
+
+    /**
+     * Gets a Client Metadata ID at the time of payment activity. Once a user initiates a PayPal payment
+     * from their device, PayPal uses the Client Metadata ID to verify that the payment is
+     * originating from a valid, user-consented device and application. This helps reduce fraud and
+     * decrease declines. This method MUST be called prior to initiating a pre-consented payment (a
+     * "future payment") from a mobile device. Pass the result to your server, to include in the
+     * payment request sent to PayPal. Do not otherwise cache or store this value.
+     *
+     * @param callback
+     */
+    public void getClientMetadataId(GetClientMetadataIdCallback callback) {
+        braintreeClient.getConfiguration((configuration, error) -> {
+            if (configuration != null) {
+                Context appContext = braintreeClient.getApplicationContext();
+                String clientMetadataId =
+                    payPalDataCollector.getClientMetadataId(appContext, configuration);
+                callback.onResult(clientMetadataId, null);
+            } else {
+                callback.onResult(null, error);
+            }
+        });
+    }
 }

Drop-In/src/main/java/com/braintreepayments/api/DropInClientParams.java

@@ -10,6 +10,7 @@ class DropInClientParams {
     private BraintreeClient braintreeClient;
     private GooglePayClient googlePayClient;
     private PaymentMethodClient paymentMethodClient;
+    private PayPalDataCollector payPalDataCollector;
     private DropInSharedPreferences dropInSharedPreferences;
     private FragmentActivity activity;
     private Lifecycle lifecycle;
@@ -32,6 +33,15 @@ DropInClientParams braintreeClient(BraintreeClient braintreeClient) {
         return this;
     }
 
+    PayPalDataCollector getPayPalDataCollector() {
+        return payPalDataCollector;
+    }
+
+    DropInClientParams payPalDataCollector(PayPalDataCollector payPalDataCollector) {
+        this.payPalDataCollector = payPalDataCollector;
+        return this;
+    }
+
     GooglePayClient getGooglePayClient() {
         return googlePayClient;
     }

Drop-In/src/main/java/com/braintreepayments/api/GetClientMetadataIdCallback.java

@@ -0,0 +1,8 @@
+package com.braintreepayments.api;
+
+import androidx.annotation.Nullable;
+
+public interface GetClientMetadataIdCallback {
+
+    void onResult(@Nullable String clientMetadataId, @Nullable Exception error);
+}

build.gradle

@@ -18,6 +18,7 @@ buildscript {
             "googlePay" : "com.braintreepayments.api:google-pay:$brainTreeVersion",
             "card" : "com.braintreepayments.api:card:$brainTreeVersion",
             "dataCollector" : "com.braintreepayments.api:data-collector:$brainTreeVersion",
+            "payPalDataCollector" : "com.braintreepayments.api:paypal-data-collector:$brainTreeVersion",
             "unionPay" : "com.braintreepayments.api:union-pay:$brainTreeVersion",
             "cardForm" : "com.braintreepayments:card-form:$brainTreeVersion"
     ]