Why my PagingSource doesn't give me any data?

Question

The Elements of the project that don't work

And I check if data is no null and do default submitList in the fragment.

Btw here is the link to the documentation

SearchPagingSource

These logs aren't even shown

    class SearchPagingSource(
    private val api: Api,
    private val query: String
) : PagingSource<Int, Image>
    () {

    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, Image> {
        val position = params.key ?: 0

        Log.d("SUPERTAG", "response")
        return try {
            val response =
                api.search(query, position, params.loadSize, Locale.getDefault().language)
            val list = ArrayList<Image>()
            response.gif.forEach {
                list.add(it.image)
            }
            Log.d("SUPERTAG", "response: $list")
            LoadResult.Page(
                data = list,
                prevKey = null,
                nextKey = if (list.isEmpty()) null else position + 15
            )
        } catch (e: IOException) {
            // no connection
            Log.d("SUPERTAG", "IOException: ${e.message}")
            LoadResult.Error(e)
        } catch (e: HttpException) {
            // error loading
            Log.d("SUPERTAG", "HttpException: ${e.message}")
            LoadResult.Error(e)
        }
    }
}

ViewModel

Null because of the null that returned by the repository.

class SearchViewModel : ViewModel() {
    private val searchRepository = SearchRepository.getInstance()

    private val _query = MutableLiveData<String>()

    private val _results = _query.map { data ->
        searchRepository.search(data).value
    }

    val results = _results

    private val _error = MutableLiveData<String>()
    val error: LiveData<String> = _error

    @SuppressLint("StaticFieldLeak")
    private lateinit var progressBar: ProgressBar

    fun initProgress(progress: ProgressBar) {
        progressBar = progress
    }

    fun search(query: String, errorLoading: String) {
        viewModelScope.launch {
            try {
                progressBar.visibility = View.VISIBLE
                _query.value = query
                Log.d("SUPERTAG", "result2: ${searchRepository.search(_query.value!!).value}")
                progressBar.visibility = View.GONE
            } catch (e: Exception) {
                _error.value = e.message
            }
        }
    }
}

Repository Exactly this part of the code returns null, I checked It by logs. I guess I do smth wrong with parameters or in general.

object SearchRepository {
    private lateinit var instance: SearchRepository
    private val app: App by lazy {
        App().getInstance()
    }

    fun getInstance(): SearchRepository {
        instance = this
        app.initRetrofit()
        return instance
    }

    fun search(query: String) = Pager(
            config = PagingConfig(
                15,
                maxSize = 50,
                enablePlaceholders = false
            ),
            pagingSourceFactory = {
                SearchPagingSource(app.api, query)
            }
        ).liveData

}

If I do like this, I get at least snackbar and an error. Usually it shows nothing and even no progressBar. So, If I add jumpThreshold = 0, I get a snackbar with an error that I don't have usually.

fun search(query: String) = Pager(
            config = PagingConfig(
                pageSize = 15,
                jumpThreshold = 0
            ),
            pagingSourceFactory = {
                SearchPagingSource(app.api, query)
            }
        ).liveData

Edit

So, I did it with flow and it works a bit, but Im still not getting a list in my recycler.

Repository

fun getListData(query: String): Flow<PagingData<Image>> {
        return Pager(
            config = PagingConfig(
                pageSize = 15,
                maxSize = 50,
                enablePlaceholders = true
            ), pagingSourceFactory = {
                SearchPagingSource(query = query, api = app.api)
            }).flow
    }

ViewModel

fun search(query: String){
            viewModelScope.launch {
                try {
                    searchRepository.getListData(query).collectLatest {
                        it.map {
                            Log.d("SUPERTAG", "image $it")
                        }
                        Log.d("SUPERTAG", it.toString())
                        _results.value = it
                    }
                } catch (e: Exception){
                    _error.value = e.message
                }
            }
    }

Answer 1

The answer was in the adapter!

    class SearchAdapter(
    diffCallback: DiffUtil.ItemCallback<Image>,
    private val clickListener: (url: String) -> Unit
) : PagingDataAdapter<Image, SearchAdapterViewHolder>(diffCallback) {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): SearchAdapterViewHolder {
        val inflater = LayoutInflater.from(parent.context)
        val view = inflater.inflate(R.layout.list_item, parent, false)
        return SearchAdapterViewHolder(view)
    }

    override fun onBindViewHolder(holder: SearchAdapterViewHolder, position: Int) {
        val item = getItem(position)

        if(item != null){
        holder.imageView.setOnClickListener {
            clickListener(item.original.url)
        }
        holder.bind(item)
        }
    }
}