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kotlinlang

Hi, folks! Does anyone know if there is any particular reason why you cannot use a `Flow` with data binding, but it needs to be a `StateFlow`, for one-way binding? As far as my imagination goes, you should be able to just collect a simple `Flow` and update the view from the `FlowCollector`, but I might be missing something. Also, are there any known workarounds? I didn't manage to find anything by Googling.
The context is that we are looking to migrate from LiveData to Flows, and we have hundreds, if not thousands of LDs that are bound in XML that now would become Flows, and going through each and one of them to transform them to a `StateFlow` using the `stateIn()` operator is not very feasible :disappointed:

I think `StateFlow` is desired over `Flow` because it requires an initial state similar to `LiveData`.

`LiveData` doesn't require an initial value though
<https://developer.android.com/reference/androidx/lifecycle/LiveData#LiveData()|https://developer.android.com/reference/androidx/lifecycle/LiveData#LiveData()>

Yeah, but what does it really mean for you to bind something without a value to UI element?  That's the issue with LiveData.  When you use StateFlow, you always have a value, even if that value happens to be null (when you use a nullable type parameter), which i don't recommend anyway.

Plus, databinding should support Flow and StateFlow out of the box as far as I know.  It has for quite some time.

This is and old, but relevant article: <https://proandroiddev.com/stateflow-with-one-and-twoway-databinding-on-android-cf4e6c847988>

I agree, an advantage of `StateFlow` is that you always have a value. The problem is that sometimes it's harder to have a `StateFlow` at hand. For instance imagine if you need to apply several operations like `map`, the result will be a simple `Flow` because of the suspending nature of the operators the value won't be there right away. You could then do `.stateIn(scope, started, initialValue)`, but when you have a lot of different fields you need to do this for, it becomes annoying, to say the least, or you might not even have a sensible `initialValue` to begin with.
What would I expect to happen when using `Flow` would be similar with what happens when using `LiveData`, which is for nothing to be set on the view until a value is emitted :shrug: