Develop Reference

How to change database value if user's internet is switched off

For the past few days i've been trying to show the online/offline status of a user.. For this i have a register activity where they register and their info gets saved in firebase and if they exit an activity i have overriden its onstop method and made the value to set to offline... but if the user suddenly loses internet connection it still shows online.. i cant change it to offline because internet is needed to make a change in the database and the use doesn't have internet... SO how do i set the database value to offline... i googled quite some stuff about this but didnt find anything... Can anyone please help me out please
My code
#Override
protected void onStart() {
super.onStart();
fetchData();
// mDatabaseReference.child("UserData").child(UID).child("Online").setValue("True");
}
#Override
protected void onStop() {
super.onStop();
fetchData();
// mDatabaseReference.child("UserData").child(UID).child("Online").setValue(false);
}

What you're trying to do is known as a presence system. The Firebase Database has a special API to allow this: onDisconnect(). When you attach a handler to onDisconnect(), the write operation you specify will be executed on the server when that server detects that the client has disconnected.
From the documentation on managing presence:
Here is a simple example of writing data upon disconnection by using the onDisconnect primitive:
DatabaseRef presenceRef = FirebaseDatabase.getInstance().getReference("disconnectmessage");
// Write a string when this client loses connection
presenceRef.onDisconnect().setValue("I disconnected!");
In your case this could be as simple as:
protected void onStart() {
super.onStart();
fetchData();
DatabaseReference onlineRef = mDatabaseReference.child("UserData").child(UID).child("Online");
onlineRef.setValue("True");
onlineRef.onDisconnect().setValue("False");
}
Note that this will work in simple cases, but will start to have problems for example when your connection toggles rapidly. In that case it may take the server longer to detect that the client disappears (since this may depends on the socket timing out) than it takes the client to reconnect, resulting in an invalid False.
To handle these situations better, check out the sample presence system in the documentation, which has more elaborate handling of edge cases.

Google play game Leaderboard can not submitScore

I am trying to submit a score at a Google Game Play Leaderboard using the following code line:
if(mGoogleApiClient.isConnected()) {
Games.Leaderboards.submitScoreImmediate(mGoogleApiClient, "xxxxxxxxxxxxxxxxx", myScore).setResultCallback(new ResultCallback<Leaderboards.SubmitScoreResult>() {
#Override
public void onResult(Leaderboards.SubmitScoreResult arg0) {
Log.e(TAG, "getStatusCode= "+arg0.getStatus().getStatusCode());
Log.e(TAG, "score submitted: "+arg0.getScoreData().toString());
}
});
}
The score is not uploaded and I get the following error ScoreSubmissionData:
ScoreSubmissionData{PlayerId=xxxxxxxxxxxxxxxx, StatusCode=2, TimesSpan=DAILY, Result=null, TimesSpan=WEEKLY, Result=null, TimesSpan=ALL_TIME, Result=null}
StatusCode=2 means STATUS_CLIENT_RECONNECT_REQUIRED
I call the above line inside onConnected() method so it is sure that I am connected...

Try reconnecting or apply a Loop-switch sequence to handle error like this. You might want to check this example showing how to use STATUS_CLIENT_RECONNECT_REQUIRED of the com.google.android.gms.games.GamesClient class.
Base on the document:
STATUS_CLIENT_RECONNECT_REQUIRED
The AppStateClient is in an inconsistent state and must reconnect to the service to resolve the issue.
Also here is the list of AppStateClient that you may encounter.
Hope this helps.

I have found the solution.
The application i make was first build to an other Laptop.
Now i have bought a new Laptop, i installed Android Studio and tried to change some code lines. But when i submitted a Score my Google play account (API Manager) could not recognize my new Laptop because it had a different SHA1 key.
So i added my new SHA1 key at the credentials of the API Manager and everything was ok !!

Google Drive Android API: Deleted folder still exists in query

Running the code below, I create a folder with Google Drive Android API on a tablet. After a few seconds, delete that folder from a remote location on a PC. When I re-run the code, the API still thinks 'MyFolder' exists, even though it was deleted and not visible in the Google Drive app on the tablet. The folder persistance finally disappears after a while and the code works as expected. Is this expected behavior for Cloud drives?
Query query = new Query.Builder()
.addFilter(Filters.and(Filters.eq(
SearchableField.TITLE, "MyFolder"),
Filters.eq(SearchableField.TRASHED, false)))
.build();
Drive.DriveApi.query(getGoogleApiClient(), query)
.setResultCallback(new ResultCallback<DriveApi.MetadataBufferResult>() {
#Override
public void onResult(DriveApi.MetadataBufferResult result) {
if (!result.getStatus().isSuccess()) {
showMessage("Cannot create folder in the root.");
} else {
boolean isFound = false;
for(Metadata m : result.getMetadataBuffer()) {
if(!isFound) {
if (m.getTitle().equals("MyFolder")) {
showMessage("Folder exists");
isFound = true;
}
}
}
if(!isFound) {
showMessage("Folder not found; creating it.");
MetadataChangeSet changeSet = new MetadataChangeSet.Builder()
.setTitle("MyFolder")
.build();
Drive.DriveApi.getRootFolder(getGoogleApiClient())
.createFolder(getGoogleApiClient(), changeSet)
.setResultCallback(new ResultCallback<DriveFolder.DriveFolderResult>() {
#Override
public void onResult(DriveFolder.DriveFolderResult result) {
if (!result.getStatus().isSuccess()) {
showMessage("Error while trying to create the folder");
} else {
mThwingAlbertFolderId = result.getDriveFolder().getDriveId();
showMessage("Created a folder: " + mThwingAlbertFolderId);
}
}
});
}
}
}
});

What you are seeing, is a 'normal' behavior of the GDAA, that can be explained if you look closer at the 'Lifecycle of a Drive file' diagram (warning: I've never seen the source code, just assuming from what I observed).
See, the GDAA, unlike the REST Api, creates a layer that does its best to create caching and network traffic optimization. So, when you manipulate the file/folder from the 'outside' (like the web app), the GDAA layer has no knowledge of the fact until it initiates synchronization, controlled by it's own logic. I myself originally assumed that GooDrive has this under control by dispatching some kind of notification back to the GDAA, but it apparently is not the case. Also, some Googlers mentioned 'requestSync()' as a cure, but I never succeeded to make it work.
What you think you're doing, is polling the GooDrive. But effectively, you're polling the GDAA (local GooPlaySvcs) whose DriveId is still valid (not updated), unlike the real GooDrive object that is already gone.
This is one thing that is not clearly stated in the docs. GDAA is not the best Api for EVERY application. It's caching mechanism is great for transparently managing online/offline states, network traffic optimization. battery life, ... But in your situation, you may be better off by using the REST Api, since the response you get reflects the current GooDrive state.
I myself faced a similar situation and had to switch from the GDAA back to the REST (and replaced polling with a private GCM based notification system). Needless to say, by using the REST Api, your app gets more complex, usually requiring sync adapter / service to do the data synchronization, managing network states, ... all the stuff GDAA gives you for free).
In case you want to play with the 2 apis side-by side, there are two identical CRUD implementation you can use (GDAA, REST) on Github.
Good Luck

Google drive api does not sync immediately, That is why the deleted folders are still showing, so you have to force google drive to sync using requestSync()
Drive.DriveApi.requestSync(mGoogleApiClient).await();
I fount an example snippet here:
http://wiki.workassis.com/android-google-drive-api-deleted-folder-still-exists-in-query/

As Sean mentioned, the Drive Android API caches metadata locally to reduce bandwidth and battery usage.
When you perform an action on the device, e.g. creating a folder, we attempt to apply that action on the server as soon as possible. Though there can be delays due to action dependencies and content transfers, you will generally see the results reflected on the server very quickly.
When an action is performed on the server, e.g. by deleting a folder via the web client, this action is reflected on the device the next time the Drive Android API syncs. In order to conserve battery and bandwidth, sync frequency depends on how the API is being used as this is a priority for users.
If you need to guarantee that a sync has occurred, you can explicitly request a sync using DriveApi.requestSync() and wait on the result. This is currently rate limited to 1 per minute, which is frequently hit during testing, but should have a much smaller impact on real world usage.
Please let us know on our issue tracker if this sync behavior is causing issues for your use case so we can investigate solutions.

Google drive uses its own lifecycle for Drive api and manage all things in cache that's why if you delete some file or folder and try to access using google drive apis it is still available because it is stored in cache so you need to explicitly call requestSync() method for that then after that cache will be updated and gives you that folder or file not found.
below is code for that:
Drive.DriveApi.requestSync(mGoogleApiClient).setResultCallback(new ResultCallback<Status>() {
#Override
public void onResult(#NonNull Status status) {
Log.e("sync_status", status.toString());
if (status.getStatus().isSuccess()) {
setRootFolderDriveId();
}
}
});
and don't call Drive.DriveApi.requestSync(mGoogleApiClient).await() because your main thread will block so it will crash. use above one and after get successful callback you can do your operation on google drive because it's updated.

You can do it in main thread:
Drive.DriveApi.requestSync(mGoogleApiClient).setResultCallback(new ResultCallback<com.google.android.gms.common.api.Status>() {
#Override
public void onResult(com.google.android.gms.common.api.Status status) {
if (!status.getStatus().isSuccess()) {
Log.e("SYNCING", "ERROR" + status.getStatusMessage());
} else {
Log.e("SYNCING", "SUCCESS");
// execute your code to interact with Google Drive
}
}
});

I was having the same issue and using "Drive.DriveApi.requestSync" did the trick.
Also I suggest taking a look at https://github.com/francescocervone/RxDrive because you can concatenate the sync to other drive operations using rxandroid.
For example, this becomes a delete-and-sync operation:
Observable<Boolean> deleteFile = rxDrive.delete(file);
Observable<Void> syncDrive = rxDrive.sync();
Observable.concat(deleteFile, syncDrive);

The reason why you get listed deleted files from your query is that Google Drive has a "Trash" folder that is "searchable". You need to empty your trash first.

Android: Google Analytics availability in Google Play Services?

Google Analytics has been announced to become part of the rolling out Google Play Services 4.3, however it is not yet included in the Google Play Services packages list:
http://developer.android.com/reference/gms-packages.html
Any idea when it will become available, and will it be safe to be used straight away, or will it be better to wait for some time to make sure every user has Google Play Services 4.3 already installed?

I've noticed some other differences.
Tracker
To get a new Tracker, use the newTracker() method (accepts both a String value and an int value [for XML configuration]):
googleTracker = gaInstance.getTracker(GA_KEY); // OLD
googleTracker = gaInstance.newTracker(GA_KEY); // NEW
EasyTracker
EasyTracker has now disappeared, so we will have to use GoogleAnalytics.getInstance(this).reportActivityStart(this) as reported by Paito.
Setters
The googleTracker.set() method is no longer available. It has been replaced with more specialised methods, for example:
googleTracker.set(Fields.SCREEN_NAME, null); // OLD
googleTracker.setScreenName(null); // NEW
Event creation
The googleTracker.send() method has also seen some changes.
googleTracker.send(MapBuilder
.createEvent(category, action, label, value)
.build()); // OLD
googleTracker.send(new HitBuilders.EventBuilder()
.setCategory(category)
.setAction(action)
.setLabel(label)
.setValue(value)
.build()); // NEW
AppView
It now becomes
googleTracker.send(MapBuilder.createAppView().build()); // OLD
googleTracker.send(new HitBuilders.AppViewBuilder().build()); // NEW
AppViewBuilder
AppViewBuilder has now been deprecated, replaced by the new ScreenViewBuilder class. (thanks Hai Phong for the tip!)
For those who are running into (or have already dealt with) the Dalvik's 64K methods limit, there are now 3K methods that you will be able to get rid of in your application, thanks to this integration.

It's part of the package list now.
I think the basic functionality works something like this...
import com.google.android.gms.analytics.GoogleAnalytics;
#Override
protected void onStart() {
super.onStart();
GoogleAnalytics.getInstance(this).reportActivityStart(this);
}
#Override
protected void onStop() {
super.onStop();
GoogleAnalytics.getInstance(this).reportActivityStop(this);
}

As per conversation in order to use Easytracker replacement with
GoogleAnalytics.getInstance(this).reportActivityStart(this);
GoogleAnalytics.getInstance(this).reportActivityStop(this);
You need to add your config to AndroidManifest like
<meta-data android:name="com.google.android.gms.analytics.globalConfigResource" android:resource="#xml/analytics_global_config" />
I'm still having to get instance of Tracker to send Events, may be somebody else would have better luck at replacing
EasyTracker.getInstance(mContext).send(MapBuilder....)

The documentation for Google Analytics SDK v4 (now part of Google Play Services) has just been published!
https://developers.google.com/analytics/devguides/collection/android/v4/

How to notify users about an Android app update?

I've built an Android app which is now on Play Market. From time to time, I make updates to it, and I'd like to let users know that a new version is available.
How can I send an update notification to the users of the app?

You do not need to do anything specific for this. Since you mentioned that you are using Google Play, the update notification is taken care of by Google Play.
You just need to update the APK with a higher versionCode and Google Play should do the rest.

Update 2020: now you can use in-app updates mechanism
Docs: https://developer.android.com/guide/playcore/in-app-updates

You can do this in a lot of ways, depending on when you want the user to be able to see that there is an update available.
If you want the user to know about the update when the app is started, just create a utility method (inside the onCreate method of your main/first Activity) that checks if a newer version is available in Google Play. If it does, display an alert dialog with a relevant message and an Intent which opens your app in Google Play when the user clicks on the positive button of the alert dialog.
If you are updating the app regularly, the user will keep getting this alert dialog every time the app is started and hence, may get irritated. Thus, this is not the best approach.
If you want the user to get a notification on the phone (and not when the user starts the app), you can use the AlarmManager class to schedule a background service which checks for an update at regular intervals. If the service finds that an upgrade is actually available, publish a notification with an intent that opens your app in Google Play.
Of course, another approach is to leave it to the OS itself. If the user has not set the "Automatically update" preference for your app, the user will get a notification regularly about an update available for your, as well as any other apps.
But not all users enable background data on their devices, so this is not completely reliable.
In the end, you must respect the users preferences. If the user does not want to automatically update the app, or does not want to see a nagging dialog box whenever he/she starts your app, don't alert the user about the update.
In my opinion, you should create a PreferenceActivity that has a preference like "Check for updates regularly", which can be set from within your app. If it is set, do the needful in your own service. May be even give the user an option to select the period after which the service will check for an update.
I hope this helps!

It is up to each phone owner if she wants to be notified on new versions by google play, and it's up to each phone's manufacturer if this is to be enabled by default.
If you however are in a situation where you "require" the user to update to the new version to be compatible with some form of protocol or you have a similar similar use case where you have a server component somewhere, you might want to notify the user of a potential version conflict in the UI based on information about what is the latest version.
This information can be grabbed directrly from google play, however as #Yahel pointed out in this question google play is a closed system with no official API, and you might need to rely on unpredictable undocumented API. There is an unofficial API library here.
This leaves only one option, which is to keep this information on your own server. If you allready have a serverside this might be trivial. Simply put the latest version in an XML file and retreive that at regular intervals from your code. If the version code is outdated, trigger the notification in your UI. Here is an example implementation for doing that.
I hope this was helpful :-)

I know this is an old question but still if people are coming here to check this question, Google is now providing official support for in-app notification for application update the full documentation can be found here

Use this : https://www.push-link.com/

Google Play will notify your users that the app has an update via the notification bar.
If you set up a notification system yourself, the likely result would be that, although the user is notified of an update sooner, when he/she goes to Google Play to install the update it will not yet be available. This is because there is a lag from the time you "publish" an app/update and the time until it appears on Play. Telling your users that there is an update when the update is unavailable would only lead to confusion and frustration.
My advice: stick with Google's update notification system and don't worry about trying to get users an update 15 minutes sooner.

Some people use Android Cloud-to-Device Messaging (C2DM) to notify their users of updates. I don't think I'd bother, since I think Google Play does a pretty good job of notifying me of updates already, and implementing C2DM adds a whole new dimension to writing an app (because it requires a server component). But maybe you want to offer your users a richer update notification than you get from Google Play.

#Davek804's answer above is wrong. android:versionCode is an integer value that represents the version of the application code, relative to other versions, so using "1.5b" there is incorrect. Use "15" (or "150") instead

Found a nice solution for your problem:
Let´s say you want to check for version updates manually on app start and notify your users for the new Update.
Step 1: Download android-market-api (not the .jar file, the full project!)
Step 2: After importing it to eclipse, write in your activity the following code:
MarketService ms = new MarketService(activity);
ms.level(MarketService.REVISION).checkVersion();
now, we need to modify MarketService.java, because it seems to be broken.
Step 3: rewrite callback method and add the following methods
protected void callback(String url, JSONObject jo, AjaxStatus status){
if(jo == null) return;
String googlePlayversion = jo.optString("version", "0");
String smartphone_version = "";
PackageInfo pInfo;
try {
pInfo = act.getPackageManager().getPackageInfo(act.getPackageName(), 0);
smartphone_version = pInfo.versionName;
} catch (NameNotFoundException e) {}
boolean new_version_avaible = compare(smartphone_version, googlePlayversion);
if(new_version_avaible){
showUpdateDialog(jo);
}
}
private static boolean compare(String v1, String v2) {
String s1 = normalisedVersion(v1);
String s2 = normalisedVersion(v2);
int cmp = s1.compareTo(s2);
String cmpStr = cmp < 0 ? "<" : cmp > 0 ? ">" : "==";
System.out.printf("result: "+"'%s' %s '%s'%n", v1, cmpStr, v2);
if(cmpStr.contains("<")){
return true;
}
if(cmpStr.contains(">")||cmpStr.contains("==")){
return false;
}
return false;
}
public static String normalisedVersion(String version) {
return normalisedVersion(version, ".", 4);
}
public static String normalisedVersion(String version, String sep, int maxWidth) {
String[] split = Pattern.compile(sep, Pattern.LITERAL).split(version);
StringBuilder sb = new StringBuilder();
for (String s : split) {
sb.append(String.format("%" + maxWidth + 's', s));
}
return sb.toString();
}
If you want to test it, modify googlePlayversion string to a higher version than your local one.
The source comparison method I used is from How do you compare two version Strings in Java?

There is also a very good approach for checking version and give user in app notification or when you want to forcefully update the application if you can decide the first connection of your app with the server.In the response of the first request you can send the current version of app stored on your server and then on client end you can take the appropriate action.
Advantages of this approach-:
1-No extra request for version no.
2-It is also applicable if you are downloading the app other than the google playstore.
3-you can also use this idea if you want to check the version at particular operation of your app ex- transaction(if you add a new payment gateway.)

Don't know if you want to walk extra miles. You can try out google appengine, which serve version number for your app and let you android app check the appengine to see if there is a new version when the application is launched. That way, it does not matter if your app is in google play market nor amazon app store nor if it is installed on the phone without those two via sideloading. It is not very hard to setup appengine just for serving your application version in json. Replace "Hello World" string with your app version name ...

This can be using a simple webservice just this is one of the way to acheive.
i.e., when ever the app launch hit that webservice with the current version of the user app and on the server you need to check whether any new version is available or not(Must maintain the newest version of the app) and send the corresponding response to the user. If any newer version is available prompt the user to download the newest version of the application and if no newest version is available then allow the user to continue.
Hope so atleast something must be useful to you.

There are two models that are basically used to tackle the issue.
Pull Based
Push Based
Its depends on the architecture or design of particular system that determines whether pull based or push mechanism is used.
For pull based model you just make one http request to concerned server regarding the new version of application. The current application version no can be saved in SQLLite in android application. This can be given to server and new version can be checked against it at the server.
For push mechanism you can use C2DM push notification service.. details of which are given at http://code.google.com/android/c2dm/

Generally when you upload a new application to Google play most users get a notification about an update, some will have the app automatically downloaded to their device, depending on the settings they have.
If you seriously want to make a notification from your app to ask them to update (so that everyone gets the notification, whatever their Google play settings are, then you will have to make a web service which returns the number of the newest version. You can then compare that inside your app and post a notification. You could use Google App Engine ( https://developers.google.com/appengine/) because that works with eclipse and java, which you probably already have.
I would not recommend this approach as it creates a lot of work for you to provide something that most users have already got.

i think this is too late but it can be help some one
public enum AppVersionUpgradeNotifier {
INSTANCE;
private static final String TAG = "AppVersionUpdateManager";
private static final String PREFERENCES_APP_VERSION = "pref_app_version_upgrade";
private static final String KEY_LAST_VERSION = "last_version";
private SharedPreferences sharedPreferences;
private VersionUpdateListener versionUpdateListener;
private boolean isInitialized;
public static synchronized void init(Context context, VersionUpdateListener versionUpdateListener) {
if (context == null || versionUpdateListener == null) {
throw new IllegalArgumentException(TAG + " : Context or VersionUpdateListener is null");
}
if (!INSTANCE.isInitialized) {
INSTANCE.initInternal(context, versionUpdateListener);
} else {
Log.w(TAG, "Init called twice, ignoring...");
}
}
private void initInternal(Context context, VersionUpdateListener versionUpdateListener) {
this.sharedPreferences = context.getSharedPreferences(PREFERENCES_APP_VERSION, Context.MODE_PRIVATE);
this.versionUpdateListener = versionUpdateListener;
this.isInitialized = true;
checkVersionUpdate();
}
private void checkVersionUpdate() {
int lastVersion = getLastVersion();
int currentVersion = getCurrentVersion();
if (lastVersion < currentVersion) {
if (versionUpdateListener.onVersionUpdate(currentVersion, lastVersion)) {
upgradeLastVersionToCurrent();
}
}
}
private int getLastVersion() {
return sharedPreferences.getInt(KEY_LAST_VERSION, 0);
}
private int getCurrentVersion() {
return BuildConfig.VERSION_CODE;
}
public void upgradeLastVersionToCurrent() {
sharedPreferences.edit().putInt(KEY_LAST_VERSION, getCurrentVersion()).apply();
}
public interface VersionUpdateListener {
boolean onVersionUpdate(int newVersion, int oldVersion);
}
}
use it on
public class MyApplication extends Application implements AppVersionUpgradeNotifier.VersionUpdateListener {
#Override
public void onCreate() {
super.onCreate();
AppVersionUpgradeNotifier.init(this,this);
}
#Override
public boolean onVersionUpdate(int newVersion, int oldVersion) {
//do what you want
return true;
}
}

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
android:versionCode="1.5b"
android:versionName="1.5b">
When you re-upload your app to Google Play, if these two attributes have been changed from the previous upload, Google Play will automatically send notifications to users who have installed your app. This is the AndroidManifest file.