CODEWITHSUNDEEP
androidandroid-loadermanagerandroid-databaseandroid-loader
Ofek Ron
Ofek Ron

Reputation: 8578

Can the overhead of implementing ContentProvider for an internally used Database be avoided?

The Android developer guide states :

You don't need to develop your own provider if you don't intend to share your data with other applications.

So It is understood that if i have a SQLite DB used entirely locally in the app then a ContentProvider should not be needed (having a lot of boilerplate code writing avoided), but I didnt get whats the "Android" way to query this DB on the background? (with as less overhead of re-inventing the wheel as possible)

It may seem that this task is what Loaders are for, as sateted in the docs :

loaders make it easy to asynchronously load data in an activity or fragment.

but there is no subclass of Loader that can carry this task out, The closest subclass - CursorLoader is desgined to be coupled with a ContentResolver. So, am i missing something? Is there a third party implementation of Loader that does that or is there another approach?

Thanks!

Upvotes: 0

Views: 159

Answers (3)

Maxim G
Maxim G

Reputation: 1489

No need for ContentProvider if you don't

  • share data with other processes (applications);

  • build App Widget;

  • integrate your own search suggestions with the Android Quick Search Box;

... and you do not want a fancy syncing and querying data with auto-UI update.

Actually, you can try to wrap read/write DB operation in AsyncTaskLoader (AsyncTask that respects activity lifecycle). Also you will have to implement your own observers to update views (one more option to use data binding).

Upvotes: 0

CommonsWare
CommonsWare

Reputation: 1007349

whats the "Android" way to query this DB on the background?

Whatever you want. Use an AsyncTask. Use a plain Thread. Use an IntentService. See if your preferred ORM has an asynchronous option, or hooks into RxJava/RxAndroid, or something.

IOW, there is no single "Android" way.

It may seem that this task is what Loaders are for, as sateted in the docs :

A Loader is only relevant in cases where you want the UI layer to be working with the database fairly directly. You can only use a Loader with an Activity or Fragment.

am i missing something?

You are welcome to create your own subclass of AsyncTaskLoader that works with SQLite directly, perhaps using the source code to CursorLoader as a source of inspiration.

Is there a third party implementation of Loader that does that

I had one, once. However, I discontinued it.

Upvotes: 2

DeeV
DeeV

Reputation: 36045

A Loader is a mechanism that hooks in to the Activity lifecycle that can be used to asynchronously load any kind of data whether ContentProvider, network, or you just need to crunch a bunch of numbers.

At the base there is a Loader called the AsyncTaskLoader which a CursorLoader actually inherits from. This can be used to provide the base level functionality of a Loader. All you have to do is implement a data model that you need to load, then implement the AsyncTaskLoader#loadInBackground() method to get it. In this case, you would query the database then return the results in a form of your choosing. Maybe in this case you don't want to return a Cursor but you want to create Pojo's that represent a row in your Cursor for example.

As a quick implementation, you may be able to take CursorLoader's source code and have it query from your database instead of using a ContentResolver.

Upvotes: 1

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