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Is this a bug in LiveData?

Steps:
1. Call `liveData.postValue(StateOne)` 
2. Call `liveData.postValue(StateTwo)`
Actual:
The LiveData observer only receives `StateTwo` because inside `postValue`, while the `mPostValueRunnable` is being posted from the first call, `pendingData` gets replaced by the second call.

Is that expected or should LiveData be posting two separate runnables, one by one?

It is expected in LiveData that you only get the latest state, yes

I guess that's fair for mutually exclusive states where you'd want to ignore the result of the first one. Just strange because updating `liveData.value`  is expected to deliver every state...right?

LiveData is for latest state only. If you `post`, you'll only get the latest

Thanks Ian. But when you set `liveData.value` , that will deliver every time, right? Or is that also subject to the same behaviour as `postValue`?

While it might emit values multiple times for `setValue()`, you shouldn’t write your code expecting that to happen. If you need to know the full history of events that are emitted, you should probably look into coroutine Channels or Flow instead, both of which can be tied into the `lifecycleScope` to achieve the same kind of app state guarantees that LiveData does

Thanks <@UD17D4K8W>, I'll check out Flows with `lifecycleScope`. LiveData's been working well for the last year and a half with the app though. :man-shrugging:

If an Observer sets the value, later Observers will get that new value and not the previous one

So certainly possible even without `postValue`

But to Casey's point, you shouldn't ever be using LiveData in event like cases where you need every value. The last value should be the complete and updated state of the world

Thanks for the clarification :slightly_smiling_face: