ListenableFutureRemoteMediator


ListenableFuture-based compatibility wrapper around RemoteMediator's suspending APIs.

Summary

Public constructors

<Key : Any, Value : Any> ListenableFutureRemoteMediator()
android

Public functions

final suspend RemoteMediator.InitializeAction
android
open ListenableFuture<RemoteMediator.InitializeAction>

Callback fired during initialization of a PagingData stream, before initial load.

android
final suspend RemoteMediator.MediatorResult
load(loadType: LoadType, state: PagingState<Key, Value>)
android
abstract ListenableFuture<RemoteMediator.MediatorResult>
loadFuture(loadType: LoadType, state: PagingState<Key, Value>)

Implement this method to load additional remote data, which will then be stored for the PagingSource to access.

android

Public constructors

ListenableFutureRemoteMediator

<Key : Any, Value : Any> ListenableFutureRemoteMediator()

Public functions

initialize

final suspend fun initialize(): RemoteMediator.InitializeAction

initializeFuture

open fun initializeFuture(): ListenableFuture<RemoteMediator.InitializeAction>

Callback fired during initialization of a PagingData stream, before initial load.

This function runs to completion before any loading is performed.

Returns
ListenableFuture<RemoteMediator.InitializeAction>

InitializeAction indicating the action to take after initialization:

load

final suspend fun load(loadType: LoadType, state: PagingState<Key, Value>): RemoteMediator.MediatorResult

loadFuture

abstract fun loadFuture(loadType: LoadType, state: PagingState<Key, Value>): ListenableFuture<RemoteMediator.MediatorResult>

Implement this method to load additional remote data, which will then be stored for the PagingSource to access. These loads take one of two forms:

  • type == LoadType.PREPEND / LoadType.APPEND The PagingSource has loaded a 'boundary' page, with a null adjacent key. This means this method should load additional remote data to append / prepend as appropriate, and store it locally.

  • type == LoadType.REFRESH The app (or initialize) has requested a remote refresh of data. This means the method should generally load remote data, and replace all local data.

The runtime of this method defines loading state behavior in boundary conditions, which affects e.g., LoadState callbacks registered to androidx.paging.PagingDataAdapter.

NOTE: A PagingSource.load request which is fulfilled by a page that hits a boundary condition in either direction will trigger this callback with LoadType.PREPEND or LoadType.APPEND or both. LoadType.REFRESH occurs as a result of initialize.

Parameters
loadType: LoadType

LoadType of the boundary condition which triggered this callback.

state: PagingState<Key, Value>

A copy of the state including the list of pages currently held in memory of the currently presented PagingData at the time of starting the load. E.g. for load(loadType = END), you can use the page or item at the end as input for what to load from the network.

Returns
ListenableFuture<RemoteMediator.MediatorResult>

MediatorResult signifying what LoadState to be passed to the UI, and whether there's more data available.