how to fetch message content from notifications of GCM chat application?

Question

I have made a GCM chat application. The problem I am facing is that I am not able to fetch message content and sender name from the notifications that are received by the receiver. When I click the notification icon, it takes me to chat activity but does not display the message and neither the sender's name. Plz help me solve this problem by using pending intent.Here is GcmIntentService.java.

public class GcmIntentService extends IntentService {
public static final int NOTIFICATION_ID = 1;
private NotificationManager mNotificationManager;
NotificationCompat.Builder builder;
public static final String TAG = "GcmIntentService";

public GcmIntentService() {
    super("GcmIntentService");
}

@Override
protected void onHandleIntent(Intent intent) {

    Bundle extras = intent.getExtras();
    GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
    // The getMessageType() intent parameter must be the intent you received
    // in your BroadcastReceiver.
    String messageType = gcm.getMessageType(intent);

    if (!extras.isEmpty()) { // has effect of unparcelling Bundle
        /*
         * Filter messages based on message type. Since it is likely that
         * GCM will be extended in the future with new message types, just
         * ignore any message types you're not interested in, or that you
         * don't recognize.
         */
        if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR
                .equals(messageType)) {
            sendNotification("Send error: " + extras.toString());
        } else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED
                .equals(messageType)) {
            sendNotification("Deleted messages on server: "
                    + extras.toString());
            // If it's a regular GCM message, do some work.
        } else if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE
                .equals(messageType)) {
            sendNotification("Received Message : "
                    + extras.getString("message"));
            Log.i(TAG, "Received: " + extras.toString());
        }
    }
    // Release the wake lock provided by the WakefulBroadcastReceiver.
    GcmBroadcastReceiver.completeWakefulIntent(intent);


}

// Put the message into a notification and post it.
// This is just one simple example of what you might choose to do with
// a GCM message.
private void sendNotification(String msg) {

    mNotificationManager = (NotificationManager) this
            .getSystemService(Context.NOTIFICATION_SERVICE);

          PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
            new Intent(this, ChatActivity.class), 0);

    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
            this).setSmallIcon(R.drawable.ic_launcher)
            .setContentTitle("GCM Notification")
            .setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
            .setContentText(msg);

    mBuilder.setContentIntent(contentIntent);
    mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
}

/*Intent notificationIntent = new Intent(getApplicationContext(), viewmessage.class);
  notificationIntent.putExtra("NotificationMessage", notificationMessage);
  notificationIntent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);
  PendingIntent pendingNotificationIntent = PendingIntent.getActivity(getApplicationContext(),notificationIndex,notificationIntent,PendingIntent.FLAG_UPDATE_CURRENT);
  notification.flags |= Notification.FLAG_AUTO_CANCEL;
  notification.setLatestEventInfo(getApplicationContext(), notificationTitle, notificationMessage, pendingNotificationIntent);
*/

}

Here is ChatActivity.java:

public class ChatActivity extends ActionBarActivity {

HttpPost httppost;
StringBuffer buffer;
HttpResponse response;
HttpClient httpclient;
List<NameValuePair> nameValuePairs;
Utils utils;

static String TAG = "GCM DEMO";
String user_name;
String regid;
String chattingToName, chattingToDeviceID;

String SENDER_ID = "abc"; //protected
String API_KEY = "xyz"; //protected

EditText edtMessage;
ListView chatLV;
DBOperation dbOperation;

ChatListAdapter chatAdapater;
ArrayList<ChatPeople> ChatPeoples;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    utils = new Utils(this);

    chatLV = (ListView) findViewById(R.id.listView1);
    edtMessage = (EditText) findViewById(R.id.editText_message);

    ChatPeoples = new ArrayList<ChatPeople>();

    regid = utils.getRegistrationId();

    Bundle b = getIntent().getExtras();

    if (b != null) {
        user_name = b.getString("chattingFrom");
        chattingToName = b.getString("chattingToName");
        chattingToDeviceID = b.getString("chattingToDeviceID");

        Log.i(TAG, "Chat From : " + user_name + " >> Chatting To : "
                + chattingToName);
    }

    registerReceiver(broadcastReceiver, new IntentFilter(
            "CHAT_MESSAGE_RECEIVED"));

    dbOperation = new DBOperation(this);
    dbOperation.createAndInitializeTables();

    populateChatMessages();

    chatLV.setTranscriptMode(ListView.TRANSCRIPT_MODE_ALWAYS_SCROLL);
    chatLV.setStackFromBottom(true);

    getSupportActionBar().setTitle("Chatting with : " + chattingToName);
}

private void populateChatMessages() {

    getData();
    if (ChatPeoples.size() > 0) {
        chatAdapater = new ChatListAdapter(this, ChatPeoples);
        chatLV.setAdapter(chatAdapater);
    }

}

void clearMessageTextBox() {

    edtMessage.clearFocus();
    edtMessage.setText("");

    hideKeyBoard(edtMessage);

}

private void hideKeyBoard(EditText edt) {
    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(edt.getWindowToken(), 0);
}

void addToDB(ChatPeople curChatObj) {

    ChatPeople people = new ChatPeople();
    ContentValues values = new ContentValues();
    values.put(people.getPERSON_NAME(), curChatObj.getPERSON_NAME());
    values.put(people.getPERSON_CHAT_MESSAGE(),
            curChatObj.getPERSON_CHAT_MESSAGE());
    values.put(people.getPERSON_DEVICE_ID(),
            curChatObj.getPERSON_DEVICE_ID());
    values.put(people.getPERSON_CHAT_TO_FROM(),
            curChatObj.getPERSON_CHAT_TO_FROM());
    values.put(people.getPERSON_EMAIL(), "[email protected]");
    dbOperation.open();
    long id = dbOperation.insertTableData(people.getTableName(), values);
    dbOperation.close();
    if (id != -1) {
        Log.i(TAG, "Succesfully Inserted");
    }

    populateChatMessages();
}

void getData() {

    ChatPeoples.clear();

    Cursor cursor = dbOperation.getDataFromTable(chattingToDeviceID);
    if (cursor.getCount() > 0) {
        cursor.moveToFirst();
        do {
            // Log.i(TAG,
            // "Name = " + cursor.getString(0) + ", Message = "
            // + cursor.getString(1) + " Device ID = "
            // + cursor.getString(2));

            ChatPeople people = addToChat(cursor.getString(0),
                    cursor.getString(1), cursor.getString(3));
            ChatPeoples.add(people);
        } while (cursor.moveToNext());
    }
    cursor.close();

}

BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {

        Bundle b = intent.getExtras();

        String message = b.getString("message");

        Log.i(TAG, " Received in Activity " + message + ", NAME = "
                + chattingToName + ", dev ID = " + chattingToDeviceID);

        // this demo this is the same device
        ChatPeople curChatObj = addToChat(chattingToName, message,
                "Received");
        addToDB(curChatObj); // adding to db

        populateChatMessages();

    }
};

public void sendMessage() {

    final String messageToSend = edtMessage.getText().toString().trim();

    if (messageToSend.length() > 0) {

        Log.i(TAG, "sendMessage");

        Thread thread = new Thread() {
            @Override
            public void run() {
                try {
                    httpclient = new DefaultHttpClient();
                    httppost = new HttpPost(utils.getCurrentIPAddress2());
                    //httppost = new HttpPost("http://192.168.43.183/safety_app/gcm_engine.php");
                            //+ "GCM/gcm_engine.php");
                    nameValuePairs = new ArrayList<NameValuePair>(1);
                    nameValuePairs.add(new BasicNameValuePair("message",
                            messageToSend));

                    nameValuePairs.add(new BasicNameValuePair(
                            "registrationIDs", chattingToDeviceID));

                    nameValuePairs.add(new BasicNameValuePair("apiKey",
                            API_KEY));

                    httppost.setEntity(new UrlEncodedFormEntity(
                            nameValuePairs));
                    //ResponseHandler<String> responseHandler = new BasicResponseHandler();
                    //final String response = httpclient.execute(httppost,
                        //  responseHandler);
                    response = httpclient.execute(httppost);
                    String responseBody = EntityUtils.toString(response.getEntity());
                    utils.showToast("reached end-"+responseBody);
                    Log.i(TAG, "Response : " + responseBody);
                    if (responseBody.trim().isEmpty()) {
                        Log.d(TAG, "Message Not Sent");
                    }
                    else
                        utils.showToast("msg sent");

                } catch (Exception e) {
                    //utils.showToast("exception-"+e.getMessage());
                    Log.d(TAG, "Exception : " + e.getMessage());
                }
            }
        };

        thread.start();

    }

}

public void onDestroy() {
    super.onDestroy();
    unregisterReceiver(broadcastReceiver);
}

ChatPeople addToChat(String personName, String chatMessage, String toOrFrom) {

    Log.i(TAG, "inserting : " + personName + ", " + chatMessage + ", "
            + toOrFrom + " , " + chattingToDeviceID);
    ChatPeople curChatObj = new ChatPeople();
    curChatObj.setPERSON_NAME(personName);
    curChatObj.setPERSON_CHAT_MESSAGE(chatMessage);
    curChatObj.setPERSON_CHAT_TO_FROM(toOrFrom);
    curChatObj.setPERSON_DEVICE_ID(chattingToDeviceID);
    curChatObj.setPERSON_EMAIL("[email protected]");

    return curChatObj;

}

public void onClick(final View view) {

    if (view == findViewById(R.id.send)) {

        ChatPeople curChatObj = addToChat(chattingToName, edtMessage
                .getText().toString().trim(), "Sent");
        addToDB(curChatObj); // adding to db

        sendMessage();

        clearMessageTextBox();

    }

}
}

Answer 1

In the sendNotification method, you'll need to alter the following line:

PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, ChatActivity.class), 0);

You have to create the intent (ChatActivity.class) prior to this line and set its extras. Get the extras from the intent passed into onHandleIntent and add them to the intent you are creating.

Do keep in mind that you will need to add some flags to avoid confusion in case of multiple displayed notifications. Read this post for more details.

Answer 2

GCM can help you to display the name and Message in the notification screen. When you click on it, it opens the desired activity as you prefer (Chatactivity in your scenario).

Now the main point is, GCM's work was to notify the user who is sending message, and a short message string. When you open the ChatActivity, in onCreate method, load the new messages yourself (from your server Database or wherever they are stored), and display it to the user. Its not GCM's job to load the messages after the Activity Opens. You should manually load messages.