A generic way of backing an Android RecyclerView with a Firebase location.

• It handles all of the child events at the given Firebase location.
• It marshals received data into the given class type.
• Simplifies the management of configuration change (e.g.: device rotation) allowing the restoring of the list.

No modules, just copy FirebaseRecyclerAdapter in your project and extend it.

Create an adapter class extending FirebaseRecyclerAdapter and exposing a Viewholder and the Model of the Firebase childs: public class MyAdapter extends FirebaseRecyclerAdapter<MyAdapter.ViewHolder, MyItem> (example here).

FirebaseRecyclerAdapter constructor takes two parameters:

• query: The Firebase location to watch for data changes
• itemClass : The class of the items (childs)

FirebaseRecyclerAdapter will handle the item list (listening from a Firebase location) and you can handle the view logic in your new adapter where you must:

• Declare a constructor that calls super(params...) with the default FirebaseRecyclerAdapter constructor parameters.
• Override onCreateViewHolder and onBindViewHolder and handle your viewholder logic here like a classic adapter (in onBindViewHolder you can get the item with the getItem(int position) method of FirebaseRecyclerAdapter, e.g.:MyItem item = getItem(position).
• Implement the abstract methods itemAdded, itemChanged, itemRemoved, itemMoved that will notify you when the list changes.

Create your adapter just like you always do and pass the interested parameter to its constructor: mMyAdapter = new MyAdapter(mQuery, MyItem.class);

You're done!

Remember to call MyAdapter.destroy before destroying the adapter to remove the Firebase location listener!

If you're interested in device rotation handling you should:

• Save FirebaseRecyclerAdapter mItems and mKeys before destroying the adapter: just put them in a onSavedInstance Bundle (be careful, your must declare the item/child class model as Parcelable). You can get them with getItems() and getKeys().
• Call MyAdapter.destroy before destroying the adapter.
• Re-create the adapter (after the device rotation) passing the saved mItems and mKeys to the second constructor: mMyAdapter = new MyAdapter(mQuery, MyItem.class, mAdapterItems, mAdapterKeys);.

Here is a working example where I handled device rotation (I used Parceler to make myItem parcelable).

Thanks to FirebaseListAdapter for the starting idea.