Issue passes with the Android SDK

To use the Google Wallet Android SDK, add com.google.android.gms:play-services-pay to the dependencies section of your app-level build.gradle file:

  implementation "com.google.android.gms:play-services-pay:16.5.0"

Before saving the new object, ensure that the Google Wallet API is available on the target device by calling thegetPayApiAvailabilityStatus method in the PayClient class.

Start by adding a member variable to the activity where you will show the button and instantiate it when the activity is created:

import com.google.android.gms.pay.PayClient

private lateinit var walletClient: PayClient

override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)

  walletClient = Pay.getClient(this)

  // Additional logic in your onCreate method
}

import com.google.android.gms.pay.PayClient;

private final PayClient walletClient;

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  walletClient = Pay.getClient(application);

  // Additional logic in your onCreate method
}

If you are using other design patterns consider placing domain specific business logic appropriately. For example, if you are using the MVVM pattern, place UI related business logic in your Activity or Fragment (eg.: UI elements, activity result), and operational logic in your view model (eg.: client instantiation, network call triggers).

Next, use the PayClient to check whether the API is available:

import com.google.android.gms.pay.PayApiAvailabilityStatus

private fun fetchCanUseGoogleWalletApi() {
  walletClient
    .getPayApiAvailabilityStatus(PayClient.RequestType.SAVE_PASSES)
    .addOnSuccessListener { status ->
      if (status == PayApiAvailabilityStatus.AVAILABLE) {
        // The API is available, show the button in your UI
      } else {
        // The user or device is not eligible for using the Pay API
      }
    }
    .addOnFailureListener {
      // Hide the button and optionally show an error message
    }
}

import com.google.android.gms.pay.PayApiAvailabilityStatus;

private void fetchCanAddPassesToGoogleWallet() {
  walletClient
    .getPayApiAvailabilityStatus(PayClient.RequestType.SAVE_PASSES)
    .addOnSuccessListener(status -> {
      if (status == PayApiAvailabilityStatus.AVAILABLE) {
        // The API is available, show the button in your UI
      } else {
        // The user or device is not eligible for using the Pay API
      };
    })
    .addOnFailureListener(exception -> {
      // Google Play Services is too old, or API availability not verified
      // Hide the button and optionally show an error message
    });
}

Finally, call the method you just defined in your application when you need to determine the availability of the API.

Handle when the API is unavailable

Some reasons why the API may be unavailable include the Android or Google Play services versions being out of date, or that Google Wallet is unavailable in the user's country.

If the API is not available consider hiding the button and falling back to a different integration (e.g. using a JWT link). Note that the user may become eligible to use the API in the future.

Google Wallet provides a familiar button that you can use to trigger the Add to Google Wallet flow in your application. Vector assets for the button are available in the Button guidelines.

You can import vector assets in Android Studio under File > New > Vector Asset. Select "Local file" in the wizard, add a name (eg.: add_to_google_wallet_button.xml) and locate the file in your local drive to import it.

Now, you can use the imported drawable to add the button to your user interface:

    <ImageButton
        android:id="@+id/addToGoogleWalletButton"
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:minWidth="200dp"
        android:clickable="true"
        android:src="@drawable/add_to_google_wallet_button" />

The button has a layout_height of 48 dp and must be at least 200 dp wide.

The LoyaltyObject can be added by passing an unsigned JWT to the savePasses method. You can start the add operation as a result of clicking the Google Wallet button.

import android.os.Bundle
import android.view.View
import com.google.android.gms.samples.wallet.databinding.ActivityCheckoutBinding

private val addToGoogleWalletRequestCode = 1000

private lateinit var layout: ActivityCheckoutBinding
private lateinit var addToGoogleWalletButton: View

override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)

  // Use view binding to access the UI elements
  layout = ActivityCheckoutBinding.inflate(layoutInflater)
  setContentView(layout.root)

  addToGoogleWalletButton = layout.addToGoogleWalletButton
  addToGoogleWalletButton.setOnClickListener {
    walletClient.savePasses(newObjectJson, this, addToGoogleWalletRequestCode)
  }

  // Additional logic in your onCreate method
}

import android.os.Bundle;
import android.view.View;
import com.google.android.gms.samples.wallet.databinding.ActivityCheckoutBinding;

private static final int ADD_TO_GOOGLE_WALLET_REQUEST_CODE = 999;

private ActivityCheckoutBinding layout:
private View addToGoogleWalletButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  // Use view binding to access the UI elements
  layout = ActivityCheckoutBinding.inflate(getLayoutInflater());
  setContentView(layout.getRoot());

  addToGoogleWalletButton = layout.addToGoogleWalletButton;
  addToGoogleWalletButton.setOnClickListener(v -> {
    walletClient.savePasses(newObjectJson, this, ADD_TO_GOOGLE_WALLET_REQUEST_CODE);
  });

  // Additional logic in your onCreate method
}

Result handling

The savePasses method triggers the save flow and invokes the onActivityResult method after the save flow has completed. The implementation of onActivityResult should be similar to the following:

import android.content.Intent

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
  super.onActivityResult(requestCode, resultCode, data)

  if (requestCode == addToGoogleWalletRequestCode) {
    when (resultCode) {
      RESULT_OK -> {
        // Pass saved successfully
      }

      RESULT_CANCELED -> {
        // Save operation canceled
      }

      PayClient.SavePassesResult.SAVE_ERROR -> data?.let { intentData ->
        val errorMessage = intentData.getStringExtra(PayClient.EXTRA_API_ERROR_MESSAGE)
        // Handle error
      }

      else -> {
          // Handle unexpected (non-API) exception
      }
    }
  }
}

import android.content.Intent;

@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
  super.onActivityResult(requestCode, resultCode, data);

  if (requestCode == ADD_TO_GOOGLE_WALLET_REQUEST_CODE) {
    switch (resultCode) {
      case RESULT_OK: {
        // Pass saved successfully
        break;
      }

      case RESULT_CANCELED: {
        // Save operation canceled
        break;
      }

      case PayClient.SavePassesResult.SAVE_ERROR: {
        if (data != null) {
          String apiErrorMessage = data.getStringExtra(PayClient.EXTRA_API_ERROR_MESSAGE);
          // Handle error
        }
        break;
      }

      default: {
        // Handle unexpected (non-API) exception
      }
    }
  }
}

When the pass is successfully added, the resultCode contains the value of Activity.RESULT_OK.