{% setvar book_path %}/reference/kotlin/androidx/_book.yaml{% endsetvar %} {% include "_shared/_reference-head-tags.html" %}
RxPagingSource |
Rx-based compatibility wrapper around |
RxRemoteMediator |
RxJava3 compatibility wrapper around |
@ExperimentalCoroutinesApi <ERROR CLASS><PagingData<Value>> |
A Flowable of |
@ExperimentalCoroutinesApi <ERROR CLASS><PagingData<Value>> |
Pager<Key, Value>.observable An Observable of |
@ExperimentalCoroutinesApi <ERROR CLASS><PagingData<T>> |
<T : Any> <ERROR CLASS><PagingData<T>>.cachedIn(scope: CoroutineScope) Operator which caches an Observable of |
@ExperimentalCoroutinesApi <ERROR CLASS><PagingData<T>> |
<T : Any> <ERROR CLASS><PagingData<T>>.cachedIn(scope: CoroutineScope) Operator which caches a Flowable of |
@<ERROR CLASS> PagingData<T> |
<T : Any> PagingData<T>.filterAsync( Returns a |
@<ERROR CLASS> PagingData<R> |
<T : Any, R : Any> PagingData<T>.flatMapAsync( Returns a |
@<ERROR CLASS> PagingData<R> |
<T : R, R : Any> PagingData<T>.insertSeparatorsAsync( Returns a |
@<ERROR CLASS> PagingData<R> |
<T : Any, R : Any> PagingData<T>.mapAsync(transform: (T) -> <ERROR CLASS><R>) Returns a |
@ExperimentalCoroutinesApi
val Pager<Key, Value>.flowable: @ExperimentalCoroutinesApi <ERROR CLASS><PagingData<Value>>
A Flowable of PagingData
, which mirrors the stream provided by Pager.flow
, but exposes it as a Flowable.
@ExperimentalCoroutinesApi
val Pager<Key, Value>.observable: @ExperimentalCoroutinesApi <ERROR CLASS><PagingData<Value>>
An Observable of PagingData
, which mirrors the stream provided by Pager.flow
, but exposes it as an Observable.
@ExperimentalCoroutinesApi
fun <T : Any> <ERROR CLASS><PagingData<T>>.cachedIn(scope: CoroutineScope): @ExperimentalCoroutinesApi <ERROR CLASS><PagingData<T>>
Operator which caches an Observable of PagingData
within a CoroutineScope
.
cachedIn
multicasts pages loaded and transformed by a PagingData
, allowing multiple observers on the same instance of PagingData
to receive the same events, avoiding redundant work, but comes at the cost of buffering those pages in memory.
Calling cachedIn
is required to allow calling androidx.paging.AsyncPagingDataAdapter on the same instance of PagingData
emitted by Pager
or any of its transformed derivatives, as reloading data from scratch on the same generation of PagingData
is an unsupported operation.
Parameters | |
---|---|
scope: CoroutineScope |
The |
@ExperimentalCoroutinesApi
fun <T : Any> <ERROR CLASS><PagingData<T>>.cachedIn(scope: CoroutineScope): @ExperimentalCoroutinesApi <ERROR CLASS><PagingData<T>>
Operator which caches a Flowable of PagingData
within a CoroutineScope
.
cachedIn
multicasts pages loaded and transformed by a PagingData
, allowing multiple observers on the same instance of PagingData
to receive the same events, avoiding redundant work, but comes at the cost of buffering those pages in memory.
Calling cachedIn
is required to allow calling androidx.paging.AsyncPagingDataAdapter on the same instance of PagingData
emitted by Pager
or any of its transformed derivatives, as reloading data from scratch on the same generation of PagingData
is an unsupported operation.
Parameters | |
---|---|
scope: CoroutineScope |
The |
@<ERROR CLASS>
fun <T : Any> PagingData<T>.filterAsync(
predicate: (T) -> <ERROR CLASS><Boolean>
): @<ERROR CLASS> PagingData<T>
Returns a PagingData
containing only elements matching the given predicate
.
@<ERROR CLASS>
fun <T : Any, R : Any> PagingData<T>.flatMapAsync(
transform: (T) -> <ERROR CLASS><Iterable<R>>
): @<ERROR CLASS> PagingData<R>
Returns a PagingData
of all elements returned from applying the given transform
to each element, as it is loaded.
@<ERROR CLASS>
fun <T : R, R : Any> PagingData<T>.insertSeparatorsAsync(
generator: (T?, T?) -> <ERROR CLASS><R>
): @<ERROR CLASS> PagingData<R>
Returns a PagingData
containing each original element, with an optional separator generated by generator
, given the elements before and after (or null, in boundary conditions).
Note that this transform is applied asynchronously, as pages are loaded. Potential separators between pages are only computed once both pages are loaded.
import androidx.paging.insertSeparatorsAsync import androidx.paging.rxjava2.insertSeparatorsAsync /* * Create letter separators in an alphabetically sorted list. * * For example, if the input is: * "apple", "apricot", "banana", "carrot" * * The operator would output: * "A", "apple", "apricot", "B", "banana", "C", "carrot" */ pagingDataStream.map { pagingData -> // map outer stream, so we can perform transformations on each paging generation pagingData.insertSeparatorsAsync { before: String?, after: String? -> Maybe.fromCallable<String> { if (after != null && before?.first() != after.first()) { // separator - after is first item that starts with its first letter after.first().toUpperCase().toString() } else { // no separator - either end of list, or first letters of before/after are the same null } }.subscribeOn(Schedulers.computation()) } }
import androidx.paging.insertSeparatorsAsync import androidx.paging.map import androidx.paging.rxjava2.insertSeparatorsAsync open class UiModel data class ItemUiModel(val item: Item) : UiModel() data class SeparatorUiModel(val char: Char) : UiModel() /* * Create letter separators in an alphabetically sorted list of Items, with UiModel objects. * * For example, if the input is (each an `Item`): * "apple", "apricot", "banana", "carrot" * * The operator would output a list of UiModels corresponding to: * "A", "apple", "apricot", "B", "banana", "C", "carrot" */ pagingDataStream.map { pagingData -> // map outer stream, so we can perform transformations on each paging generation pagingData .map { item -> ItemUiModel(item) // convert items in stream to ItemUiModel } .insertSeparatorsAsync { before: ItemUiModel?, after: ItemUiModel? -> Maybe.fromCallable<UiModel> { if (after != null && before?.item?.label?.first() != after.item.label.first()) { // separator - after is first item that starts with its first letter SeparatorUiModel(after.item.label.first().toUpperCase()) } else { // no separator - either end of list, or first letters of before/after are the same null } }.subscribeOn(Schedulers.computation()) } }
@<ERROR CLASS>
fun <T : Any, R : Any> PagingData<T>.mapAsync(transform: (T) -> <ERROR CLASS><R>): @<ERROR CLASS> PagingData<R>
Returns a PagingData
containing the result of applying the given transform
to each element, as it is loaded.