RxRemoteMediator


@ExperimentalPagingApi
public abstract class RxRemoteMediator<Key extends Object, Value extends Object> extends RemoteMediator


RxJava2 compatibility wrapper around RemoteMediator's suspending APIs.

Summary

Public constructors

<Key extends Object, Value extends Object> RxRemoteMediator()

Public methods

final @NonNull RemoteMediator.InitializeAction
@NonNull Single<@NonNull RemoteMediator.InitializeAction>

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

final @NonNull RemoteMediator.MediatorResult
load(
    @NonNull LoadType loadType,
    @NonNull PagingState<@NonNull Key, @NonNull Value> state
)
abstract @NonNull Single<@NonNull RemoteMediator.MediatorResult>
loadSingle(
    @NonNull LoadType loadType,
    @NonNull PagingState<@NonNull Key, @NonNull Value> state
)

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

Public constructors

RxRemoteMediator

public <Key extends Object, Value extends Object> RxRemoteMediator()

Public methods

initialize

public final @NonNull RemoteMediator.InitializeAction initialize()

initializeSingle

Added in 3.0.0
public @NonNull Single<@NonNull RemoteMediator.InitializeActioninitializeSingle()

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

This function runs to completion before any loading is performed.

Returns
@NonNull Single<@NonNull RemoteMediator.InitializeAction>

InitializeAction indicating the action to take after initialization:

load

public final @NonNull RemoteMediator.MediatorResult load(
    @NonNull LoadType loadType,
    @NonNull PagingState<@NonNull Key, @NonNull Value> state
)

loadSingle

Added in 3.0.0
public abstract @NonNull Single<@NonNull RemoteMediator.MediatorResultloadSingle(
    @NonNull LoadType loadType,
    @NonNull PagingState<@NonNull Key, @NonNull Value> state
)

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
@NonNull LoadType loadType

LoadType of the boundary condition which triggered this callback.

@NonNull PagingState<@NonNull Key, @NonNull Value> state

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
@NonNull Single<@NonNull RemoteMediator.MediatorResult>

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