Develop Reference

"Too many Calendar deletes" error by Android calendar provider

I am using calendar provider to create and delete events.
The problem occurs in some devices when I try to remove events. Android OS shows a notification saying:
"Too many Calendar deletes"
with options to proceed.
I couldn't find an answer to fix it in Android, only read about calendar API limitation. But it's unacceptable to offer a feature to clientes with this notification.
I am running the following line to remove an event:
context.getContentResolver().delete(eventUri, null, null);
Thanks!

I'm afraid, there is no "correct" way to bypass this message and you also shouldn't even try. This is shown because the sync adapter has set the tooManyDeletions flag in the SyncResult object to true after trying to sync.
The sync manager will always show this message if the flag is set to true.
The number of allowed deletions is defined by the respective sync adapter or by the API it's syncing to. So if you see the message depends on the account type and maybe even on the version of the sync adapter.
This is a mechanism to protect the user's data from being deleted due to a mistake (either by himself or by broken software).
You could try to trick the SyncManager and the sync adapter by triggering a sync on the respective account with the SYNC_EXTRAS_OVERRIDE_TOO_MANY_DELETIONS flag being set by your code, but you really shouldn't do that. Actually I would consider this a bug in Android if it works.
You should communicate this to the user and sell it as a feature.
Update:
To trigger a sync with SYNC_EXTRAS_OVERRIDE_TOO_MANY_DELETIONS call this:
Bundle extras = new Bundle();
extras.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true);
extras.putBoolean(ContentResolver.SYNC_EXTRAS_OVERRIDE_TOO_MANY_DELETIONS, true);
ContentResolver.requestSync(accountOfCalendar, CalendarContract.Authority, extras);
accountOfCalendar is the account of the calendar that you deleted the events from.
Use it with care.

Re initate Sync adapter in android

I'm able to successfully create Sync adapter in my phone, but i'm not able to handle a particular scenario.
My task sync app, requires the tasks permission to fetch tasks or it applicable for getting permission for any service from Google server. this scenario occurs for the first time, if the user moves to Google account without launching the application.
1) Go to Settings --> Accounts and sync --> Choose a Google account,
2) there the tasks sync content provider will be present.
3) Once i press on Sync, since for the first time the sync provider do not have access to Tasks or any Google services etc.. accounts it raises userRecoverableException
4) With help of Notification provider i will raise a push notification in my catch block.
Here how i'm doing, e is the userRecoverableException intent.
PendingIntent pendingNotificationIntent = PendingIntent.getActivity(
mContext, constants.REQUEST_AUTHORIZATION, e.getIntent(),
PendingIntent.FLAG_UPDATE_CURRENT
| PendingIntent.FLAG_ONE_SHOT);
4) once user click on notification it will open a authentication window, user approves permission for your app to fetch calender, contacts, task etc service.
5) Now how to re initiate the sync once user completes the authentication part?. Also i notice some app shows a red color exclamatory icon next to sync icon, saying "sync is experiencing problems it will be back shortly". Once they get permission automatically they will resume and sync.
Here how to get notification to restart sync or resume as soon as user authenticate the permission

Here is the solution,
we need to use the syncResult.stats.numAuthExceptions to tell about exception, it throws message automatically. syncResult.delayUntil will wait and restart sync after elapsing time
How to show sync failed message

Check if Sync is Enabled within Android App

Is there a way to check, programmatically within my Android app, whether a particular setting under Settings > Accounts and Sync > Data & Synchronization is enabled or not?
Is there a way to check if the general sync settings are enabled?
Thanks!
If it helps to know "why," I'm currently rolling my own sync functionality (not using SyncAdapter). However, if possible I'd like to have my sync service listed under Data & Synchronization. Right now I'm planning to hack a dummy sync service that does nothing and have my app's sync service query whether or not the dummy sync service is enabled. That will tell me whether to sync or not.

To know if a sync is enabled (and not active as rajpara's answer do), use this:
AccountManager am = AccountManager.get(YourActivity.this);
Account account = am.getAccountsByType(YOUR_ACCOUNT_TYPE)[0];
boolean isYourAccountSyncEnabled = ContentResolver.getSyncAutomatically(account, DataProvider.AUTHORITY);
boolean isMasterSyncEnabled = ContentResolver.getMasterSyncAutomatically();
The "master" sync status is the global sync switch the user can use to disable all sync on his phone. If the master sync is off, your account won't sync, even if your account sync status tells that it's enabled.
As #HiB mentionned, the android.permission.READ_SYNC_SETTINGS permission is needed to access the sync status. android.permission.WRITE_SYNC_SETTINGS is needed to enable/disable it.
You also need android.permission.GET_ACCOUNTS to get the accounts, as MeetM mentionned.

You can check whether sync is enable or not with the help of below code and this Document
AccountManager am = AccountManager.get(YourActivity.this);
Account account = am.getAccountsByType(Const.ACCOUNT_TYPE)[0];
if(ContentResolver.isSyncActive(account, DataProvider.AUTHORITY){
// sync is enable
}
You can also set enable/disable programmatically with the help of this ContentResolver.setSyncAutomatically and ContentResolver.setMasterSyncAutomatically
Update :
isSyncActive returns true if there is currently a sync operation for the given account or authority in the pending list, or actively being processed.

boolean isEnabled = ContentResolver.getSyncAutomatically(account, MyProvider);
if(isEnabled)
{
...do something
}
Works for me

Why does ContentResolver.requestSync not trigger a sync?

I am trying to implement the Content-Provider-Sync Adapter pattern as discussed at Google IO - slide 26. My content provider is working, and my sync works when I trigger it from the Dev Tools Sync Tester application, however when I call ContentResolver.requestSync(account, authority, bundle) from my ContentProvider, my sync is never triggered.
ContentResolver.requestSync(
account,
AUTHORITY,
new Bundle());
Edit -- added manifest snippet
My manifest xml contains:
<service
android:name=".sync.SyncService"
android:exported="true">
<intent-filter>
<action
android:name="android.content.SyncAdapter" />
</intent-filter>
<meta-data android:name="android.content.SyncAdapter"
android:resource="#xml/syncadapter" />
</service>
--Edit
My syncadapter.xml associated with my sync service contains:
<?xml version="1.0" encoding="utf-8"?>
<sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
android:contentAuthority="AUTHORITY"
android:accountType="myaccounttype"
android:supportsUploading="true"
/>
Not sure what other code would be useful. The account passed to requestSync is of "myaccounttype" and the AUTHORITY passed to the call matches my syc adapter xml.
Is ContentResolver.requestSync the correct way to request a sync? It looks like the sync tester tool binds directly to the service and calls start sync, but that seems like it defeats the purpose of integrating with the sync architecture.
If that is the correct way to request a sync then why would the sync tester work, but not my call to ContentResolver.requestSync? Is there something I need to pass in the bundle?
I am testing in the emulator on devices running 2.1 and 2.2.

Calling requestSync() will only work on an {Account, ContentAuthority} pair that is known to the system. Your app needs to go through a number of steps to tell Android that you are capable of synchronizing a specific kind of content using a specific kind of account. It does this in the AndroidManifest.
1. Notify Android that your application package provides syncing
First off, in AndroidManifest.xml, you have to declare that you have a Sync Service:
<service android:name=".sync.mySyncService" android:exported="true">
<intent-filter>
<action android:name="android.content.SyncAdapter" />
</intent-filter>
<meta-data
android:name="android.content.SyncAdapter"
android:resource="#xml/sync_myapp" />
</service>
The name attribute of the <service> tag is the name of your class to connect up sync... I'll talk to that in a second.
Setting exported true makes it visible to other components (needed so ContentResolver can call it).
The intent filter lets it catch an intent requesting sync. (This Intent comes from ContentResolver when you call ContentResolver.requestSync() or related scheduling methods.)
The <meta-data> tag will be discussed below.
2. Provide Android a service used to find your SyncAdapter
So the class itself... Here's an example:
public class mySyncService extends Service {
private static mySyncAdapter mSyncAdapter = null;
public SyncService() {
super();
}
#Override
public void onCreate() {
super.onCreate();
if (mSyncAdapter == null) {
mSyncAdapter = new mySyncAdapter(getApplicationContext(), true);
}
}
#Override
public IBinder onBind(Intent arg0) {
return mSyncAdapter.getSyncAdapterBinder();
}
}
Your class must extend Service or one of its subclasses, must implement public IBinder onBind(Intent), and must return a SyncAdapterBinder when that's called... You need a variable of type AbstractThreadedSyncAdapter. So as you can see, that's pretty much everything in that class. The only reason it's there is to provide a Service, that offers a standard interface for Android to query your class as to what your SyncAdapter itself is.
3. Provide a class SyncAdapter to actually perform the sync.
mySyncAdapter is where the real sync logic itself is stored. Its onPerformSync() method gets called when it's time to sync. I figure you already have this in place.
4. Establish a binding between an Account-type and a Content Authority
Looking back again at AndroidManifest, that strange <meta-data> tag in our service is the key piece that establishes the binding between a ContentAuthority and an account. It externally references another xml file (call it whatever you like, something relevant to your app.) Let's look at sync_myapp.xml:
<?xml version="1.0" encoding="utf-8" ?>
<sync-adapter
xmlns:android="http://schemas.android.com/apk/res/android"
android:contentAuthority="com.android.contacts"
android:accountType="com.google"
android:userVisible="true" />
Okay, so what does this do? It tells Android that the sync adapter we've defined (the class that was called out in the name element of the <service> tag that includes the <meta-data> tag that references this file...) will sync contacts using a com.google style account.
All your contentAuthority strings have to all match, and match with what you're syncing -- This should be a string you define, if you're creating your own database, or you should use some existing device strings if you're syncing known data types (like contacts or calendar events or what have you.) The above ("com.android.contacts") happens to be the ContentAuthority string for contacts type data (surprise, surprise.)
accountType also has to match one of those known account types that are already entered, or it has to match one you're creating (This involves creating a subclass of AccountAuthenticator to get auth on your server... Worth an article, itself.) Again, "com.google" is the defined string identifying... google.com style account credentials (again, this should not be a surprise.)
5. Enable Sync on a given Account / ContentAuthority pair
Finally, sync has to be enabled. You can do this in the Accounts & Sync page in the control panel by going to your app and setting the checkbox next to your app within the matching account. Alternately, you can do it in some setup code in your app:
ContentResolver.setSyncAutomatically(account, AUTHORITY, true);
For sync to occur, your account/authority pair must be enabled to sync (like above) and the overall global sync flag on the system must be set, and the device must have network connectivity.
If your account/authority sync or the global sync are disabled, calling RequestSync() does have an effect -- It sets a flag that sync has been requested, and will be performed as soon as sync is enabled.
Also, per mgv, setting ContentResolver.SYNC_EXTRAS_MANUAL to true in the extras bundle of your requestSync will ask android to force a sync even if global sync is off (be respectful of your user here!)
Finally, you can setup a periodic scheduled sync, again with ContentResolver functions.
6. Consider implications of multiple accounts
It is possible to have more than one account of the same type (two #gmail.com accounts set up on one device or two facebook accounts, or two twitter accounts, etc...) You should consider the application implications of doing that... If you have two accounts, you probably don't want to try to sync both of them into the same database tables. Maybe you need to specify that only one can be active at a time, and flush the tables and resync if you switch accounts. (through a property page that queries what accounts are present). Maybe you create a different database for each account, maybe different tables, maybe a key column in each table. All application specific and worthy of some thought. ContentResolver.setIsSyncable(Account account, String authority, int syncable) might be of interest here. setSyncAutomatically() controls whether an account/authority pair is checked or unchecked, whereas setIsSyncable() provides a way to uncheck and grey out the line so the user can't turn it on. You might set one account Syncable and the other not Syncable (dsabled).
7. Be aware of ContentResolver.notifyChange()
One tricky thing. ContentResolver.notifyChange() is a function used by ContentProviders to notify Android that the local database has been changed. This serves two functions, first, it will cause cursors following that content uri to update, and in turn requery and invalidate and redraw a ListView, etc... It's very magical, the database changes and your ListView just updates automatically. Awesome. Also, when the database changes, Android will request Sync for you, even outside your normal schedule, so that those changes get taken off the device and synced to the server as rapidly as possible. Also awesome.
There's one edge case though. If you pull from the server, and push an update into the ContentProvider, it will dutifully call notifyChange() and android will go, "Oh, database changes, better put them on the server!" (Doh!) Well-written ContentProviders will have some tests to see if the changes came from the network or from the user, and will set the boolean syncToNetwork flag false if so, to prevent this wasteful double-sync. If you're feeding data into a ContentProvider, it behooves you to figure out how to get this working -- Otherwise you'll end up always performing two syncs when only one is needed.
8. Feel happy!
Once you have all this xml metadata in place, and sync enabled, Android will know how to connect everything up for you, and sync should start working. At this point, a lot of things that are nice will just click into place and it will feel a lot like magic. Enjoy!

I was caling setIsSyncable after AccountManager setAuthToken method. But setAuthToken returned function before setIsSyncable was reached. After order changes everything worked fine!

I noticed the that the requestSync will trigger the sync implementation when there is internet connection

How do I implement an Account on Android without a SyncAdapter

I am implementing a login system for an Android application utilizing the built-in accounts system (with the AccountManager APIs).
All is well and good on Android 2.2+, but on Android 2.1 not including a SyncAdapter causes reboots in the account settings screen (see http://code.google.com/p/android/issues/detail?id=5009 and AccountManager without a SyncAdapter?)
To get around this I implemented a stub SyncAdapter, which just returns null from IBinder onBind(Intent intent), and added the relevant stuff to the manifest. This resolves the reboot issue on Android 2.1.
However it introduces a further problem: after an account is added the Android system will, sometime later, initiate an account sync. Although no errors occur (indeed my SyncAdapter does nothing, it has no way to cause errors unless by returning null), the sync icon stays stuck in the notification bar at the top. This results in the Android sync system maintaining a permanent wake-lock, preventing the device from sleeping.
The account does not list any syncable components in the account settings screen (under the 'Data and synchronization' header), and always displays 'Sync is off' for the sync status in the list of accounts (even while the sync icon is visible in the notifications bar). Disabling account syncing does not remove the problem. Removing the account stops the problem.
My guess is I should not be returning null. Should I be returning a basic implementation of ThreadedSyncAdapter? Any help getting an account system without an associated sync working properly on 2.1 and 2.2+ is much appreciated.

Since this is the only question I've seen related to this problem, here's a >year late answer. I also came across the permanent wake-lock problem due to the android system syncing my custom account automatically.
The best way to handle this, which requires minimum code and actually makes it so the account never syncs unless specifically called to sync in code:
ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 0);
Now this requires that the moment you create your account you call this static method. Whereas the first parameter being the account to set this setting for, the second parameter being the used contentprovider's authority, and the third being the integer that when set to a positive number enables syncing, when set to 0 disables syncing and when set to anything else makes it unknown. The authority to use can be found inside your "sync_something.xml" under the contentAuthority attribute, which is used by your SyncAdapter :
<sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
android:contentAuthority="com.android.contacts"
android:accountType="com.myapp.account"/> <!-- This being your own account type-->
The above xml file is specified inside the service part of your AndroidManifest.xml:
<service android:name=".DummySyncAdapterService"
exported="true"
android:process=":contacts">
<intent-filter>
<action android:name="android.content.SyncAdapter" />
</intent-filter>
<meta-data android:name="android.content.SyncAdapter"
android:resource="#xml/sync_something" /> <!--This points to your SyncAdapter XML-->
</service>
This is the code snippet I use to create my custom account inside my LoginActivity:
Account account = new Account("John Doe", "com.myapp.account");
ContentResolver.setIsSyncable(account, ContactsContract.AUTHORITY, 0);
AccountManager am = AccountManager.get(LoginActivity.this);
boolean accountCreated = am.addAccountExplicitly(account, "Password", null);
Bundle extras = LoginActivity.this.getIntent().getExtras();
if(extras != null){
if (accountCreated) {
AccountAuthenticatorResponse response = extras.getParcelable(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE);
Bundle result = new Bundle();
result.putString(AccountManager.KEY_ACCOUNT_NAME, "John Doe");
result.putString(AccountManager.KEY_ACCOUNT_TYPE, "com.myapp.account");
response.onResult(result);
}
}
The great part of this is that when the system tries to sync the service, it checks if the service is syncable first, if it is set to false it cancels the syncing. Now you don't have to create your own ContentProvider nor does your ContentProvider get shown under Data and Synchronization. However you do need to have a stub implementation of AbstractThreadedSyncAdapter which returns an IBinder inside it's onBind method. And last but not least it makes it so that an user can't enable syncing or use the "Sync Now" button for this account unless you've added the functionality inside your app.

I sort of solved my own problem: you cannot return null from the onBind method of your service - you must return the IBinder of an AbstractThreadedSyncAdapter.
This has the undesired effect of adding an entry into the Data and Synchronization section of the account settings page, even though my implementation of AbstractThreadedSyncAdapter does nothing; I was hoping to avoid this.
To summarize, in order to make use of the accounts system in Android you must:
Implement a service that has an IntentFilter for android.content.SyncAdapter.
This service must return the IBinder of an AbstractThreadedSyncAdapter implementation from it's onBind method.
This then necessitates that you have a ContentProvider (can just be a stub implementation) that is referred to as the contentAuthority in your SyncAdapter XML file.
This has the down-side that your ContentProvider is listed under the Data and Synchronization header on your account settings page.