Reduce friction with the new Location APIs

Posted by Aaron Stacy, Software Engineer, Google Play services

The 11.0.0 release of the Google Play services SDK includes a new way to access LocationServices. The new APIs do not require your app to manually manage a connection to Google Play services through a GoogleApiClient. This reduces boilerplate and common pitfalls in your app.

Read more below, or head straight to the updated location samples on GitHub.

Why not use GoogleApiClient?

The LocationServices APIs allow you to access device location, set up geofences, prompt the user to enable location on the device and more. In order to access these services, the app must connect to Google Play services, which can involve error-prone connection logic. For example, can you spot the crash in the app below?

Note: we’ll assume our app has the ACCESS_FINE_LOCATION permission, which is required to get the user’s exact location using the LocationServices APIs.

public class MainActivity extends AppCompatActivity implements         GoogleApiClient.OnConnectionFailedListener {    @Override   public void onCreate(@Nullable Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      GoogleApiClient client = new GoogleApiClient.Builder(this)         .enableAutoManage(this, this)         .addApi(LocationServices.API)         .build();     client.connect();      PendingResult result =           LocationServices.FusedLocationApi.requestLocationUpdates(                  client, LocationRequest.create(), pendingIntent);      result.setResultCallback(new ResultCallback() {       @Override       public void onResult(@NonNull Status status) {         Log.d(TAG, "Result: " + status.getStatusMessage());       }     });   }    // ... }

If you pointed to the requestLocationUpdates() call, you’re right! That call throws an IllegalStateException, since the GoogleApiClient is has not yet connected. The call to connect() is asynchronous.

While the code above looks like it should work, it’s missing a ConnectionCallbacks argument to the GoogleApiClient builder. The call to request location updates should only be made after the onConnected callback has fired:

public class MainActivity extends AppCompatActivity implements          GoogleApiClient.OnConnectionFailedListener,         GoogleApiClient.ConnectionCallbacks {    private GoogleApiClient client;    @Override   protected void onCreate(@Nullable Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      client = new GoogleApiClient.Builder(this)         .enableAutoManage(this, this)         .addApi(LocationServices.API)         .addConnectionCallbacks(this)         .build();      client.connect();   }    @Override   public void onConnected(@Nullable Bundle bundle) {     PendingResult result =              LocationServices.FusedLocationApi.requestLocationUpdates(                     client, LocationRequest.create(), pendingIntent);          result.setResultCallback(new ResultCallback() {       @Override       public void onResult(@NonNull Status status) {         Log.d(TAG, "Result: " + status.getStatusMessage());       }     });   }    // ... }

Now the code works, but it’s not ideal for a few reasons:

  • It is be hard to refactor into shared classes if, for instance, you wanted to access Location Services in multiple activities.
  • The app connects optimistically in onCreate even if Location Services are not needed until later (for example, after user input).
  • It does not handle the case where the app fails to connect to Google Play services.
  • There is a lot of boilerplate connection logic before getting started with location updates.

A better developer experience

The new LocationServices APIs are much simpler and will make your code less error prone. The connection logic is handled automatically, and you only need to attach a single completion listener:

public class MainActivity extends AppCompatActivity {    @Override   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      FusedLocationProviderClient client =             LocationServices.getFusedLocationProviderClient(this);      client.requestLocationUpdates(LocationRequest.create(), pendingIntent)         .addOnCompleteListener(new OnCompleteListener() {           @Override           public void onComplete(@NonNull Task task) {             Log.d("MainActivity", "Result: " + task.getResult());           }         });   } }

The new API immediately improves the code in a few ways:

  • The API calls automatically wait for the service connection to be established, which removes the need to wait for onConnected before making requests.
  • It uses the Task API which makes it easier to compose asynchronous operations.
  • The code is self-contained and could easily be moved into a shared utility class or similar.
  • You don’t need to understand the underlying connection process to start coding.

What happened to all of the callbacks?

The new API will automatically resolve certain connection failures for you, so you don’t need to write code that for things like prompting the user to update Google Play services. Rather than exposing connection failures globally in the onConnectionFailed method, connection problems will fail the Task with an ApiException:

    client.requestLocationUpdates(LocationRequest.create(), pendingIntent)         .addOnFailureListener(new OnFailureListener() {           @Override           public void onFailure(@NonNull Exception e) {             if (e instanceof ApiException) {               Log.w(TAG, ((ApiException) e).getStatusMessage());             } else {               Log.w(TAG, e.getMessage());             }           }         });

Try it for yourself

Try the new LocationServices APIs out for yourself in your own app or head over to the android-play-location samples on GitHub and see more examples of how the new clients reduce boilerplate and simplify logic.


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