Single<T> class
A Stream which emits single event, either data or error, and then close with a done-event.
Success case: ------------(*)|------
data done
Failure case: ------------(x)|------
error done
- Inheritance
-
- Object
- Stream<
T> - StreamView<
T> - Single
- Available Extensions
- AsVoidSingleExtension
- AsVoidStreamExtension
- AsyncExpandSingleExtension
- BufferExtensions
- CollectStreamExtension
- ConcatExtensions
- ConnectableStreamExtensions
- DebounceExtensions
- DebugSingleExtension
- DebugStreamExtension
- DefaultIfEmptyExtension
- DelayExtension
- DelaySingleExtension
- DelayWhenExtension
- DistinctByExtension
- DistinctUniqueByStreamExtension
- DistinctUniqueExtension
- DoExtensions
- DoneOnErrorStreamExtension
- DoOnStreamExtensions
- DoSingleExtensions
- EndWithExtension
- EndWithManyExtension
- ExhaustMapExtension
- ExhaustMapSingleExtension
- FlatMapBatchesStreamExtension
- FlatMapEitherSingleExtension
- FlatMapExtension
- FlatMapSingleExtension
- GroupByExtension
- IgnoreElementsExtension
- IgnoreErrorsStreamExtension
- IntervalExtension
- MapNotNullExtension
- MapToExtension
- MapToSingleExtension
- MaterializeExtension
- MaxExtension
- MergeExtension
- MinExtension
- OnErrorExtensions
- OnErrorResumeSingleExtensions
- PairwiseExtension
- SampleExtensions
- ScanExtension
- SingleOrErrorSingleExtension
- SingleOrErrorStreamExtension
- SkipLastExtension
- SkipUntilExtension
- StartWithExtension
- StartWithManyExtension
- StateConnectableExtensions
- SwitchIfEmptyExtension
- SwitchMapExtension
- SwitchMapSingleExtension
- TakeLastExtension
- TakeUntilExtension
- TakeWhileInclusiveExtension
- ThrottleExtensions
- TimeIntervalExtension
- TimeStampExtension
- ToEitherSingleExtension
- ToNotReplayValueStreamExtension
- ToSingleSubscriptionStreamExtension
- ToStateStreamExtension
- ValueConnectableNotReplayStreamExtensions
- WhereNotNullExtension
- WhereTypeExtension
- WindowExtensions
- WithLatestFromExtensions
- ZipWithExtension
- Annotations
-
- @sealed
Constructors
-
Single.defer(Single<
T> singleFactory(), {bool reusable = false}) -
The defer factory waits until an observer subscribes to it, and then it
creates a Single with the given factory function.
factory
- Single.error(Object error, [StackTrace? stackTrace])
-
Creates a Single which emits a single error event before completing.
factory
-
Single.fromCallable(FutureOr<
T> callable(), {bool reusable = false}) -
Creates a Single that, when listening to it, calls a function you specify
and then emits the value returned from that function.
factory
-
Single.fromFuture(Future<
T> future) -
Creates a new single-subscription Single from the future.
factory
-
Single.fromStream(Stream<
T> source) -
This is an alias of Single.unsafeFromStream.
See Single.unsafeFromStream.
factory
-
Single.retry(Single<
T> singleFactory(), [int? count]) -
Creates a Single that will recreate and re-listen to the source
Single the specified number of times until the Single terminates
successfully.
factory
-
Single.safe(Stream<
T> source) - @internal DO NOT USE this constructor.
- Single.timer(T value, Duration duration)
-
Creates a Single which emits the given value after a specified amount of time.
factory
-
Single.unsafeFromStream(Stream<
T> source) -
Converts source Stream into a Single.
If the source Stream is already a Single, it will be returned as-is.
factory
- Single.value(T value)
-
Creates a Single which emits a single data event of
value
before completing.factory
Properties
-
first
→ Future<
T> -
The first element of this stream.
no setterinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- isBroadcast → bool
-
Whether this stream is a broadcast stream.
no setterinherited
-
isEmpty
→ Future<
bool> -
Whether this stream contains any elements.
no setterinherited
-
last
→ Future<
T> -
The last element of this stream.
no setterinherited
-
length
→ Future<
int> -
The number of elements in this stream.
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
-
single
→ Future<
T> -
The single element of this stream.
no setterinherited
-
stream
→ Stream<
T> -
@internal
DO NOT USE this getter.
no setter
Methods
-
any(
bool test(T element)) → Future< bool> -
Checks whether
test
accepts any element provided by this stream.inherited -
asBroadcastStream(
{void onListen(StreamSubscription< T> subscription)?, void onCancel(StreamSubscription<T> subscription)?}) → Stream<T> -
Returns a multi-subscription stream that produces the same events as this.
inherited
-
asyncExpand<
E> (Stream< E> ? convert(T event)) → Stream<E> -
Transforms each element into a sequence of asynchronous events.
inherited
-
asyncMap<
E> (FutureOr< E> convert(T event)) → Single<E> -
Creates a new stream with each data event of this stream asynchronously
mapped to a new event.
override
-
cast<
R> () → Single< R> -
Adapt this stream to be a
Stream<R>
.override -
contains(
Object? needle) → Future< bool> -
Returns whether
needle
occurs in the elements provided by this stream.inherited -
distinct(
[Equality< T> ? equals]) → Single<T> -
Skips data events if they are equal to the previous data event.
override
-
drain<
E> ([E? futureValue]) → Future< E> -
Discards all data on this stream, but signals when it is done or an error
occurred.
inherited
-
elementAt(
int index) → Future< T> -
Returns the value of the
index
th data event of this stream.inherited -
every(
bool test(T element)) → Future< bool> -
Checks whether
test
accepts all elements provided by this stream.inherited -
expand<
S> (Iterable< S> convert(T element)) → Stream<S> -
Transforms each element of this stream into a sequence of elements.
inherited
-
firstWhere(
bool test(T element), {T orElse()?}) → Future< T> -
Finds the first element of this stream matching
test
.inherited -
fold<
S> (S initialValue, S combine(S previous, T element)) → Future< S> -
Combines a sequence of values by repeatedly applying
combine
.inherited -
forEach(
void action(T element)) → Future< void> -
Executes
action
on each element of this stream.inherited -
handleError(
Function onError, {bool test(dynamic error)?}) → Stream< T> -
Creates a wrapper Stream that intercepts some errors from this stream.
inherited
-
join(
[String separator = ""]) → Future< String> -
Combines the string representation of elements into a single string.
inherited
-
lastWhere(
bool test(T element), {T orElse()?}) → Future< T> -
Finds the last element in this stream matching
test
.inherited -
listen(
void onData(T value)?, {Function? onError, void onDone()?, bool? cancelOnError}) → StreamSubscription< T> -
Adds a subscription to this stream.
inherited
-
map<
S> (S convert(T event)) → Single< S> -
Transforms each element of this stream into a new stream event.
override
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
pipe(
StreamConsumer< T> streamConsumer) → Future -
Pipes the events of this stream into
streamConsumer
.inherited -
reduce(
T combine(T previous, T element)) → Future< T> -
Combines a sequence of values by repeatedly applying
combine
.inherited -
singleWhere(
bool test(T element), {T orElse()?}) → Future< T> -
Finds the single element in this stream matching
test
.inherited -
skip(
int count) → Stream< T> -
Skips the first
count
data events from this stream.inherited -
skipWhile(
bool test(T element)) → Stream< T> -
Skip data events from this stream while they are matched by
test
.inherited -
take(
int count) → Stream< T> -
Provides at most the first
count
data events of this stream.inherited -
takeWhile(
bool test(T element)) → Stream< T> -
Forwards data events while
test
is successful.inherited -
timeout(
Duration timeLimit, {void onTimeout(EventSink< T> sink)?}) → Stream<T> -
Creates a new stream with the same events as this stream.
inherited
-
toList(
) → Future< List< T> > -
Collects all elements of this stream in a
List
.inherited -
toSet(
) → Future< Set< T> > -
Collects the data of this stream in a
Set
.inherited -
toString(
) → String -
A string representation of this object.
inherited
-
transform<
S> (StreamTransformer< T, S> streamTransformer) → Stream<S> -
Applies
streamTransformer
to this stream.inherited -
where(
bool test(T event)) → Stream< T> -
Creates a new stream from this stream that discards some elements.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited