1 page.title=Accessing the Wearable Data Layer 2 3 @jd:body 4 5 <div id="tb-wrapper"> 6 <div id="tb"> 7 8 <h2>This lesson teaches you to</h2> 9 <ol> 10 <li>Set up a Google Play services client to use the Wearable Data Layer APIs</li> 11 </ol> 12 13 <h2>Dependencies and Prerequisites</h2> 14 <ol> 15 <li><a href="{@docRoot}training/wearables/apps/environment.html">Creating 16 Wearable Apps > Setting up Your Environment</a></li> 17 <li><a href="{@docRoot}training/wearables/apps/creating.html">Creating 18 Wearable Apps > Creating a Project</a></li> 19 </ol> 20 </div> 21 </div> 22 23 <p>To call the data layer API, create an instance of 24 <a href="{@docRoot}reference/com/google/android/gms/common/api/GoogleApiClient.html"><code>GoogleApiClient</code></a>, 25 the main entry point for any of the Google Play services APIs. 26 </p> 27 28 <p> 29 <a href="{@docRoot}reference/com/google/android/gms/common/api/GoogleApiClient.html"><code>GoogleApiClient</code></a> 30 provides a builder that makes it easy to create an instance of the client. 31 A minimal <a href="{@docRoot}reference/com/google/android/gms/common/api/GoogleApiClient.html"><code>GoogleApiClient</code></a> looks like this: 32 </p> 33 34 <p class="note"><b>Note:</b> For now, this minimal client is enough to get started. However, see 35 <a href="{@docRoot}google/auth/api-client.html">Accessing Google Play services APIs</a> 36 for more information about creating a <a href="{@docRoot}reference/com/google/android/gms/common/api/GoogleApiClient.html"><code>GoogleApiClient</code></a>, 37 implementing its callbacks, and handling error cases.</p> 38 39 <pre style="clear:right"> 40 GoogleApiClient mGoogleAppiClient = new GoogleApiClient.Builder(this) 41 .addConnectionCallbacks(new ConnectionCallbacks() { 42 @Override 43 public void onConnected(Bundle connectionHint) { 44 Log.d(TAG, "onConnected: " + connectionHint); 45 // Now you can use the data layer API 46 } 47 @Override 48 public void onConnectionSuspended(int cause) { 49 Log.d(TAG, "onConnectionSuspended: " + cause); 50 } 51 }) 52 .addOnConnectionFailedListener(new OnConnectionFailedListener() { 53 @Override 54 public void onConnectionFailed(ConnectionResult result) { 55 Log.d(TAG, "onConnectionFailed: " + result); 56 } 57 }) 58 .addApi(Wearable.API) 59 .build(); 60 </pre> 61 62 <p>Before you use the data layer API, start a connection on your client by calling the 63 <a href="{@docRoot}reference/com/google/android/gms/common/api/GoogleApiClient.html#connect()">connect()</a> 64 method, as described in 65 <a href="{@docRoot}google/auth/api-client.html#Starting">Accessing Google Play services APIs</a>. 66 When the system invokes the <code>onConnected()</code> callback for your client, you're ready 67 to use the data layer API.</p>