Do I need to call MobileServiceSyncContext.initialize in each Activity?

Question

When using offline sync with Azure Mobile Services Android SDK, do I need to call MobileServiceSyncContext.initialize in each Activity that requires access to some table? If so, why? The local database shouldn't be initialized only once? Am I doing all wrong? Every time the method initialize is called it tries to create all tables again even if they already exist, for me it is not so good. Is there any way I can initialize the syncContext only once or at least avoid the framework running sql scripts to create tables every time the syncContext is initialized?

Thank you!

PS: I'm a newbie in Android development, so be nice :)

Answer 1

Maybe the following detail can help towards a solution. For the MobileServiceClient, you need the Application's context, not every Activity's context. So, you don't have to initialize the syncContext for every Activity. Possibly you can save it in SharedPreferences using Gson().

MobileServiceClient mClient = new MobileServiceClient(
"<MobileAppUrl>",       // Replace with the Site URL
this);                  // Your application Context

Source: [1]: https://learn.microsoft.com/en-us/azure/app-service-mobile/app-service-mobile-android-how-to-use-client-library

Answer 2

According to your description, based on my understanding, it seems that you has follow some documents and samples below to create your app using offline sync data feature.

1. Blog: Offline support in the Azure Mobile Services Android SDK
2. Sample: https://github.com/Azure/mobile-services-samples/blob/master/TodoOffline/Android/blog20140807/app/src/main/java/com/example/blog20140807/ToDoActivity.java

Per my experience & according to the javadocs of Azure Mobile Apps SDK for Android, I think you can try to add the code using the method MobileServiceSyncContext.isInitalized below for checking the MobileServiceSyncContext initialization status, based on the sample code as below, to avoid duplicate the initalization operation.

MobileServiceSyncContext syncContext = mClient.getSyncContext();

if(syncContext.isInitalized()) {

    Map<String, ColumnDataType> tableDefinition = new HashMap<String, ColumnDataType>();
    tableDefinition.put("id", ColumnDataType.String);
    tableDefinition.put("text", ColumnDataType.String);
    tableDefinition.put("complete", ColumnDataType.Boolean);
    tableDefinition.put("__version", ColumnDataType.String);

    localStore.defineTable("ToDoItem", tableDefinition);
    syncContext.initialize(localStore, handler).get();
}