I’m encountering an issue while trying to paginate data from a Ktor server using the Paging 3 library in my Android project. The error I’m receiving is:
error=java.lang.IllegalArgumentException: Unable to create converter for class com.example.realhome.domain.model.ApiResponse
The Error coming from the log in this code
@ExperimentalCoilApi
@Composable
fun listContent(propertys: LazyPagingItems<Property>,navHostController: NavHostController){
Log.d("List content", propertys.loadState.toString())
LazyColumn(contentPadding = PaddingValues(all =10.dp),
verticalArrangement = Arrangement.spacedBy(10.dp)){
items(
items = propertys,
key = {property->property.id}){
property->property?.let { Propertyitem(property = it, navHostController = navHostController) }
}
}
}
And the desired data is not showing in the app
here is the retrofit code
object networkModule {
@Provides
@Singleton
fun providehttpclient():OkHttpClient{
return OkHttpClient.Builder().readTimeout(15,TimeUnit.MINUTES)
.connectTimeout(15,TimeUnit.MINUTES).build()
}
@Provides
@Singleton
fun provideretrfitinstance(okHttpClient: OkHttpClient): Retrofit {
val contentType = "application/json".toMediaType()
return Retrofit.Builder().baseUrl(BASE_URL).client(okHttpClient)
.addConverterFactory(Json.asConverterFactory(contentType)).build()
}
}
and the project is building and installing fine but no data is showing
I tried to check the api response code and the remote mediator code and they were fine and I can’t know what went wrong
interface PropertyApi {
@GET("/RealHomes/Properites")
suspend fun getallproperties(
@Query("page") page:Int = 1
):ApiResponse
and here is the remote mediator code
@ExperimentalPagingApi
//@OptIn(ExperimentalPagingApi::class)
class propertyRemoteMediator @Inject constructor(
private val PropertyApi: PropertyApi,
private val propertyDatabase: propertyDatabase
) : RemoteMediator<Int, Property>() {
private val propertyDao = propertyDatabase.propertyDao()
private val propertyRemoteKeyDao = propertyDatabase.propertyRemoteKeyDao()
override suspend fun load(
loadType: LoadType,
state: PagingState<Int, Property>
): MediatorResult {
return try {
val page = when (loadType) {
LoadType.PREPEND -> {
val remotekey = getRemoteKeyClosetToCurrentPosition(state)
remotekey?.nextpage?.minus(1) ?: 1
}
LoadType.REFRESH -> {
val remoteKey = getRemoteKeyForFirst(state)
val prevpage = remoteKey?.prevpage
?: return MediatorResult.Success(endOfPaginationReached = remoteKey != null)
prevpage
}
LoadType.APPEND -> {
val remoteKey = getRemoteKeyForLastItem(state)
val nextpage = remoteKey?.nextpage
?: return MediatorResult.Success(endOfPaginationReached = remoteKey != null)
nextpage
}
}
val respose = PropertyApi.getallproperties(page = page)
if (respose.properties.isNotEmpty()) {
propertyDatabase.withTransaction {
if (loadType == LoadType.REFRESH) {
propertyDao.deleteAllProperties()
propertyRemoteKeyDao.deleteAllRemoteKeys()
}
val prevpage = respose.prevpage
val nextpage = respose.nextpage
val keys = respose.properties.map { property ->
propertyRemoteKey(
id = property.id,
prevpage = prevpage,
nextpage = nextpage
)
}
propertyRemoteKeyDao.addAllRemoteKeys(keys)
propertyDao.addProperty(respose.properties)
}
}
MediatorResult.Success(endOfPaginationReached = respose.nextpage == null)
} catch (e: Exception) {
return MediatorResult.Error(e)
}
TODO("Not yet implemented")
}
private suspend fun getRemoteKeyClosetToCurrentPosition(state: PagingState<Int, Property>):
propertyRemoteKey? {
return state.anchorPosition?.let { position ->
state.closestItemToPosition(position)?.id?.let { id ->
propertyRemoteKeyDao.getRemoteKey(id = id)
}
}
}
private suspend fun getRemoteKeyForFirst(state: PagingState<Int, Property>): propertyRemoteKey? {
return state.pages.firstOrNull { it.data.isNotEmpty() }?.data?.firstOrNull()
?.let { property ->
propertyRemoteKeyDao.getRemoteKey(id = property.id)
}
}
private suspend fun getRemoteKeyForLastItem(state: PagingState<Int, Property>): propertyRemoteKey? {
return state.pages.lastOrNull { it.data.isNotEmpty() }?.data?.lastOrNull()
?.let { property -> propertyRemoteKeyDao.getRemoteKey(id = property.id) }
}
}