IssueTracker

The use-case is to 'drive' a Flow stream off invalidations from Room.

For example, say you have TableOne and TableTwo and you want to combine data from both, querying in a transaction and avoiding intermediate emissions since an operation write both tables in a transaction. Then one could use such API to drive the stream, like this:

suspend fun getCombinedData(): Flow<CombinedData> {
  // Create an observer of the tables that would invalidate the flow
  return db.invalidationTracker.createObserverFlow(arrayOf("TableOne", "TableTwo")).map { _ ->
    val (dataFromTableOne, dataFromTableTwo) = db.withTransaction {
      dao.getDataOneSuspending() to dao.getDataTwoSuspending()
    }
    combineTransform(dataFromTableOne, dataFromTableTwo) // returns List<CombinedData>
  )
}