How to use with remote data

[nihk]

How to use with remote data

[heromiyo]

Hey @nihk Thanks, i followed the steps and managed to fetch the videos, working on exoplayer caching (Preloading?/PreCaching?) .
Thanks for your help

[nihk]

Hey @heromiyo, great question. In this project, all MainViewModel cares about is the VideoDataRepository interface - it doesn't know anything about how it ultimately gets the List<VideoData>. That means you can pass in any custom implementation of VideoDataRepository to the ViewModel. For example, you could create a FirebaseVideoDataRepository implementation which uses Firebase to acquire the list of videos. VideoDataRepository has the one function which returns a Flow<List<VideoData>>; that represents a stream of data that could be anything on any thread.

In your case with Firebase you'll want to get a Flow of your relevant Firebase objects then map them to a List<VideoData>. I'm not familiar with the Firebase APIs, but here's the basic idea with some contrived classes:

class FirebaseVideoDataRepository(private val firebase: Firebase) : VideoDataRepository {
    override fun videoData(): Flow<List<VideoData>> {
        return firebase.getAllVideos()
            .map { videos -> videos.toVideoData() }
    }
    
    private fun List<FirebaseVideo>.toVideoData(): List<VideoData> {
        return map { firebaseVideo ->  VideoData(mediaUri = firebaseVideo.url) }
    }
}

interface Firebase {
    fun getAllVideos(): Flow<List<FirebaseVideo>>
}

data class FirebaseVideo(val url: String)

You could change the return type of VideoDataRepository's function to have some wrapper representing state, too. E.g. fun videoData(): Flow<MyState<List<VideoData>>>. That will facilitate the Success/Error states in your example.

Note that the current state of the app in this repository won't show image previews of remote videos (only local videos). This can be achieved by simply adding a new field to the VideoData object representing the image URL of a frame preview, then using it in the RecyclerView.ViewHolder. I'll check in a commit later to make that more clear.

[nikolamakin]

hi, Have you solved it
Can I post part of the code of the response