LiveData is not updating its value after first call

Question

I have been beating my head against the wall and I cannot understand why this is happening. I am working with the new Architectural Components for Android and I am having pr

Answer 1

Writing an answer for better discussion.

So I have (in Kotlin, sry) a model that is a list of notes (it’s just a sandbox app to play w/all this) and here’s my architecture: I don’t have a Repo, but I have Activity -> ViewModel -> Dao.

So Dao exposes a LiveData>

@Query("SELECT * FROM notes")
fun loadAll(): LiveData>

My ViewModel… exposes it through:

val notesList = database.notesDao().loadAll()

and my Activity (onCreate) does…

    viewModel.notesList.observe(this,
            Observer> { notes ->
                if (notes != null) {
                    progressBar?.hide()
                    adapter.setNotesList(notes)
                }
            })

This works. The adapter is a RecyclerView adapter that does literally nothing but:

 fun setNotesList(newList: MutableList) {
        if (notes.isEmpty()) {
            notes = newList
            notifyItemRangeInserted(0, newList.size)
        } else {
            val result = DiffUtil.calculateDiff(object : DiffUtil.Callback() {
                override fun getOldListSize(): Int {
                    return notes.size
                }

                override fun getNewListSize(): Int {
                    return newList.size
                }

                override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
                    return notes[oldItemPosition].id == newList[newItemPosition].id
                }

                override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
                    val (id, title, _, priority) = newList[newItemPosition]
                    val (id1, title1, _, priority1) = notes[oldItemPosition]
                    return id == id1
                            && priority == priority1
                            && title == title1
                }
            })
            notes = newList
            result.dispatchUpdatesTo(this)
        }
    }

If ANY other part of the app modifies that list of notes, the adapter updates automagically. I hope this gives you a playground to try a simple(r?) approach.