class SignalViewer[+A] extends MapSignal[Any, A] with StrictSignal[A]
This class adds a noop observer to signal
, ensuring that its current value is computed.
It then lets you query signal
's current value with now
and tryNow
methods (see StrictSignal).
- Alphabetic
- By Inheritance
- SignalViewer
- StrictSignal
- MapSignal
- InternalTryObserver
- SingleParentObservable
- InternalObserver
- Signal
- Observable
- AnyRef
- Any
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- Public
- Protected
Type Members
- type Self[+T] = Signal[T]
- Definition Classes
- Signal → Observable
Value Members
- final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def ##(): Int
- Definition Classes
- AnyRef → Any
- final def ==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- def addInternalObserver(observer: InternalObserver[A]): Unit
Child observable should call this method on its parents when it is started.
Child observable should call this method on its parents when it is started. This observable calls onStart if this action has given it its first observer (internal or external).
- Attributes
- protected[airstream]
- Definition Classes
- Observable
- def addObserver(observer: Observer[A])(implicit owner: Owner): Subscription
Subscribe an external observer to this observable
Subscribe an external observer to this observable
- Definition Classes
- Observable
- final def asInstanceOf[T0]: T0
- Definition Classes
- Any
- def changes: EventStream[A]
- Definition Classes
- Signal
- def clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.CloneNotSupportedException]) @native() @HotSpotIntrinsicCandidate()
- def combineWith[AA >: A, B](otherSignal: Signal[B]): Signal[(AA, B)]
- Definition Classes
- Signal
- def compose[B](operator: (Signal[A]) => Signal[B]): Signal[B]
- operator
Note: Must not throw!
- Definition Classes
- Signal
- def composeAll[B](changesOperator: (EventStream[A]) => EventStream[B], initialOperator: (Try[A]) => Try[B]): Signal[B]
- changesOperator
Note: Must not throw!
- initialOperator
Note: Must not throw!
- Definition Classes
- Signal
- def composeChanges[AA >: A](operator: (EventStream[A]) => EventStream[AA]): Signal[AA]
- operator
Note: Must not throw!
- Definition Classes
- Signal
- def debugBreak(when: (A) => Boolean = _ => true): Self[A]
- Definition Classes
- Observable
- def debugLog(prefix: String = "event", when: (A) => Boolean = _ => true): Self[A]
print events using println - use for Scala values
print events using println - use for Scala values
- Definition Classes
- Observable
- def debugLogJs(prefix: String = "event", when: (A) => Boolean = _ => true): Self[A]
print events using dom.console.log - use for JS values
print events using dom.console.log - use for JS values
- Definition Classes
- Observable
- def debugSpy(fn: (A) => Unit): Self[A]
- Definition Classes
- Observable
- final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- def equals(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef → Any
- val externalObservers: ObserverList[Observer[A]]
Note: Observer can be added more than once to an Observable.
Note: Observer can be added more than once to an Observable. If so, it will observe each event as many times as it was added.
- Attributes
- protected[this]
- Definition Classes
- Observable
- final def fireError(nextError: Throwable, transaction: Transaction): Unit
- Attributes
- protected[this]
- Definition Classes
- Signal → Observable
- def fireTry(nextValue: Try[A], transaction: Transaction): Unit
Signal propagates only if its value has changed
Signal propagates only if its value has changed
- Attributes
- protected[this]
- Definition Classes
- Signal → Observable
- final def fireValue(nextValue: A, transaction: Transaction): Unit
- Attributes
- protected[this]
- Definition Classes
- Signal → Observable
- def flatMap[B, Inner[_], Output[+_] <: Observable[_]](compose: (A) => Inner[B])(implicit strategy: FlattenStrategy[Self, Inner, Output]): Output[B]
- compose
Note: guarded against exceptions
- Definition Classes
- Observable
- Annotations
- @inline()
- def fold[B](makeInitial: (A) => B)(fn: (B, A) => B): Signal[B]
- makeInitial
Note: guarded against exceptions
- fn
Note: guarded against exceptions
- Definition Classes
- Signal
- def foldRecover[B](makeInitial: (Try[A]) => Try[B])(fn: (Try[B], Try[A]) => Try[B]): Signal[B]
- makeInitial
currentParentValue => initialValue Note: must not throw
- fn
(currentValue, nextParentValue) => nextValue
- Definition Classes
- Signal
- def foreach(onNext: (A) => Unit)(implicit owner: Owner): Subscription
Create an external observer from a function and subscribe it to this observable.
Create an external observer from a function and subscribe it to this observable.
Note: since you won't have a reference to the observer, you will need to call Subscription.kill() to unsubscribe
- Definition Classes
- Observable
- final def getClass(): Class[_ <: AnyRef]
- Definition Classes
- AnyRef → Any
- Annotations
- @native() @HotSpotIntrinsicCandidate()
- def hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @native() @HotSpotIntrinsicCandidate()
- def initialValue: Try[A]
Evaluate initial value of this Signal.
Evaluate initial value of this Signal. This method must only be called once, when this value is first needed. You should override this method as
def
(noval
or lazy val) to avoid holding a reference to the initial value beyond the duration of its relevance. - val internalObservers: ObserverList[InternalObserver[A]]
Note: This is enforced to be a Set outside of the type system #performance
Note: This is enforced to be a Set outside of the type system #performance
- Attributes
- protected[this]
- Definition Classes
- Observable
- final def isInstanceOf[T0]: Boolean
- Definition Classes
- Any
- def isStarted: Boolean
- Attributes
- protected[this]
- Definition Classes
- Observable
- def kill(): Unit
- def map[B](project: (A) => B): Signal[B]
- project
Note: guarded against exceptions
- Definition Classes
- Signal → Observable
- def mapTo[B](value: => B): Self[B]
value
is passed by name, so it will be evaluated whenever the Observable fires.value
is passed by name, so it will be evaluated whenever the Observable fires. Use it to sample mutable values (e.g. myInput.ref.value in Laminar).See also: mapToValue
- value
Note: guarded against exceptions
- Definition Classes
- Observable
- def mapToValue[B](value: B): Self[B]
value
is evaluated only once, when this method is called.value
is evaluated only once, when this method is called.See also: mapTo
- Definition Classes
- Observable
- val maybeLastSeenCurrentValue: UndefOr[Try[A]]
- Attributes
- protected[this]
- Definition Classes
- Signal
- final def ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- final def notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native() @HotSpotIntrinsicCandidate()
- final def notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native() @HotSpotIntrinsicCandidate()
- def now(): A
See comment for tryNow right above
See comment for tryNow right above
- Definition Classes
- StrictSignal → Signal
- Exceptions thrown
Exception
if current value is an error
- def observe(implicit owner: Owner): SignalViewer[A]
Add a noop observer to this signal to ensure that it's started.
Add a noop observer to this signal to ensure that it's started. This lets you access .now and .tryNow on the resulting StrictSignal.
You can use
myStream.toWeakSignal.observe
to read the last emitted value from event streams just as well.- Definition Classes
- Signal
- def onAddedExternalObserver(observer: Observer[A]): Unit
- Attributes
- protected
- Definition Classes
- Signal → Observable
- final def onError(nextError: Throwable, transaction: Transaction): Unit
Must not throw
Must not throw
- Attributes
- protected[airstream]
- Definition Classes
- InternalTryObserver → InternalObserver
- final def onNext(nextValue: Any, transaction: Transaction): Unit
Must not throw
Must not throw
- Attributes
- protected[airstream]
- Definition Classes
- InternalTryObserver → InternalObserver
- def onStart(): Unit
This method is fired when this observable starts working (listening for parent events and/or firing its own events), that is, when it gets its first Observer (internal or external).
This method is fired when this observable starts working (listening for parent events and/or firing its own events), that is, when it gets its first Observer (internal or external).
onStart can potentially be called multiple times, the second time being after it has stopped (see onStop).
- Attributes
- protected[this]
- Definition Classes
- SingleParentObservable → Observable
- def onStop(): Unit
This method is fired when this observable stops working (listening for parent events and/or firing its own events), that is, when it loses its last Observer (internal or external).
This method is fired when this observable stops working (listening for parent events and/or firing its own events), that is, when it loses its last Observer (internal or external).
onStop can potentially be called multiple times, the second time being after it has started again (see onStart).
- Attributes
- protected[this]
- Definition Classes
- SingleParentObservable → Observable
- def onTry(nextParentValue: Try[Any], transaction: Transaction): Unit
Must not throw
Must not throw
- Attributes
- protected[airstream]
- Definition Classes
- MapSignal → InternalObserver
- val parent: Signal[A]
- Definition Classes
- SignalViewer → MapSignal → SingleParentObservable
- val project: (Any) => A
- Attributes
- protected[this]
- Definition Classes
- MapSignal
- def recover[B >: A](pf: PartialFunction[Throwable, Option[B]]): Signal[B]
- pf
Note: guarded against exceptions
- Definition Classes
- Signal → Observable
- val recover: Option[PartialFunction[Throwable, Option[A]]]
- Attributes
- protected[this]
- Definition Classes
- MapSignal
- def recoverIgnoreErrors: Self[A]
- Definition Classes
- Observable
- def recoverToTry: Signal[Try[A]]
Convert this to an observable that emits Failure(err) instead of erroring
Convert this to an observable that emits Failure(err) instead of erroring
- Definition Classes
- Signal → Observable
- def removeExternalObserverNow(observer: Observer[A]): Unit
- Attributes
- protected[airstream]
- Definition Classes
- Observable
- def removeInternalObserverNow(observer: InternalObserver[A]): Unit
Child observable should call Transaction.removeInternalObserver(parent, childInternalObserver) when it is stopped.
Child observable should call Transaction.removeInternalObserver(parent, childInternalObserver) when it is stopped. This observable calls onStop if this action has removed its last observer (internal or external).
- Attributes
- protected[airstream]
- Definition Classes
- Observable
- def setCurrentValue(newValue: Try[A]): Unit
- Attributes
- protected[this]
- Definition Classes
- Signal
- final def synchronized[T0](arg0: => T0): T0
- Definition Classes
- AnyRef
- def toString(): String
- Definition Classes
- AnyRef → Any
- val topoRank: Int
- Attributes
- protected[airstream]
- Definition Classes
- MapSignal → Observable
- def tryNow(): Try[A]
Initial value is only evaluated if/when needed (when there are observers)
Initial value is only evaluated if/when needed (when there are observers)
- Definition Classes
- StrictSignal → Signal
- final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException]) @native()
- final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
Deprecated Value Members
- def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable]) @Deprecated @deprecated
- Deprecated
(Since version ) see corresponding Javadoc for more information.