Firebase how to detect if cached data is available

Question

I have an application that pulls some simple data from Firebase Realtime Database, and to make things simple here is the flow that I want to have.

If phone is connected to the internet:

• Get the data from the firebase database

If phone is offline

• If there is data in firebase cache -> get data from cache
  • If there is nothing in firebase cache -> show some default data stored locally in app

The problem is that I don't see possible way to detect if data is available in firebase cache. So when phone is offline I cannot see if I should display the locally stored data or cache from firebase database.

Answer 1

Agree above answer, Firebase will do it for you, if you do it in the right way. In order to solve your problem, you should understand the difference between the two approaches of firebase offline cache - reading-from-memory and reading-from-disk.

Read this article -> https://pamartinezandres.com/lessons-learnt-the-hard-way-using-firebase-realtime-database-c609b52b9afb

in your case, just add, FirebaseDatabase.getInstance().setPersistenceEnabled(true); to enable reading from disk

and add yourReferenceForFirebase.keepSynced(true); to keep the data synched

then your app will work as you expected.

But, only this part: "If there is nothing in firebase cache -> show some default data stored locally in app", seems impossible.