ValueSubject<T> class
A subject that provides synchronous access to the most recently added item. Additionally, if a value has been added subscribers are notified immediately of that value on subscription (as well as the events that are added in the future).
ValueSubject always behaves as a broadcast stream, and as such supports multiple subscribers.
Note that ValueSubject is conceptually identical to BehaviorSubject from other Rx.net oriented libraries.
- Inheritance
-
- Object
- Stream<
T> - StreamView<
T> - ValueSubject
- Implemented types
-
- Subject<
T> - ValueStream<
T>
- Subject<
- Available extensions
Constructors
- ValueSubject.new({bool sync = false})
-
Contructs a new ValueSubject.
factory
- ValueSubject.initialValue(T initialValue, {bool sync = false})
-
Constructs a new ValueSubject seeded with an initial value.
factory
- ValueSubject.lazy(T initialValue(), {bool sync = false})
-
Constructs a new ValueSubject with an initial value that is not generated until value is
read.
factory
Properties
- error → AsyncError
-
The last emitted error,
no setteroverride
-
first
→ Future<
T> -
The first element of this stream.
no setterinherited
- hasError → bool
-
True
if an error has been emitted.no setteroverride - hashCode → int
-
The hash code for this object.
no setterinherited
- hasValue → bool
-
True
if at least one event has been emitted.no setteroverride - isBroadcast → bool
-
Whether this stream is a broadcast stream.
no setteroverride
- isConstructed → bool
-
Available on ValueStream<
Indicates if the current value is LifecycleState.constructed.LifecycleState> , provided by the LifecycleStreamExtensions extensionno setter - isDisposed → bool
-
Available on ValueStream<
Indicates if the current value is LifecycleState.disposed.LifecycleState> , provided by the LifecycleStreamExtensions extensionno setter -
isEmpty
→ Future<
bool> -
Whether this stream contains any elements.
no setterinherited
- isStarted → bool
-
Available on ValueStream<
Indicates if the current value is LifecycleState.started.LifecycleState> , provided by the LifecycleStreamExtensions extensionno setter - isStarting → bool
-
Available on ValueStream<
Indicates if the current value is LifecycleState.starting.LifecycleState> , provided by the LifecycleStreamExtensions extensionno setter - isStopped → bool
-
Available on ValueStream<
Indicates if the current value is LifecycleState.stopped.LifecycleState> , provided by the LifecycleStreamExtensions extensionno setter - isStopping → bool
-
Available on ValueStream<
Indicates if the current value is LifecycleState.stopping.LifecycleState> , provided by the LifecycleStreamExtensions extensionno setter -
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
- value → T
-
The last emitted value.
no setteroverride
Methods
-
add(
T event) → void -
Adds a data
event
to the sink.override -
addError(
Object error, [StackTrace? stackTrace]) → void -
Adds an
error
to the sink.override -
addStream(
Stream< T> stream, {bool? cancelOnError}) → Future<void> -
Consumes the elements of
stream
.override -
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)) → Stream<E> -
Creates a new stream with each data event of this stream asynchronously
mapped to a new event.
inherited
-
cast<
R> () → Stream< R> -
Adapt this stream to be a
Stream<R>
.inherited -
close(
) → Future< void> -
Closes the sink.
override
-
contains(
Object? needle) → Future< bool> -
Returns whether
needle
occurs in the elements provided by this stream.inherited -
distinct(
[bool equals(T previous, T next)?]) → Stream< T> -
Skips data events if they are equal to the previous data event.
inherited
-
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.
override
-
map<
S> (S convert(T event)) → Stream< S> -
Transforms each element of this stream into a new stream event.
inherited
-
mapValueStream<
R> (R convert(T value), {bool sync = false}) → ValueStream< R> -
Returns a ValueStream that converts each element of this stream to a new value using the
convert
function, and emits the result. -
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