trait ObservableLike[+A, Self[+T] <: ObservableLike[T, Self]] extends Serializable
Defines the available operations for observable-like instances.
- Self Type
- Self[A]
- Source
- ObservableLike.scala
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- ObservableLike
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Abstract Value Members
-
abstract
def
liftByOperator[B](operator: Operator[A, B]): Self[B]
Transforms the source using the given operator function.
-
abstract
def
transform[B](transformer: Transformer[A, B]): Self[B]
Transforms the source using the given transformer function.
Concrete Value Members
-
final
def
!=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
final
def
##(): Int
- Definition Classes
- AnyRef → Any
-
def
++[B >: A](other: Observable[B]): Self[B]
Concatenates the source with another observable.
Concatenates the source with another observable.
Ordering of subscription is preserved, so the second observable starts only after the source observable is completed successfully with an
onComplete
. On the other hand, the second observable is never subscribed if the source completes with an error. -
def
+:[B >: A](elem: B): Self[B]
Creates a new Observable that emits the given element and then it also emits the events of the source (prepend operation).
-
def
:+[B >: A](elem: B): Self[B]
Creates a new Observable that emits the events of the source and then it also emits the given element (appended to the stream).
-
final
def
==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
ambWith[B >: A](other: Observable[B]): Self[B]
Given the source observable and another
Observable
, emits all of the items from the first of these Observables to emit an item and cancel the other. -
final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
def
asyncBoundary[B >: A](overflowStrategy: OverflowStrategy[B]): Self[B]
Forces a buffered asynchronous boundary.
Forces a buffered asynchronous boundary.
Internally it wraps the observer implementation given to
onSubscribe
into a BufferedSubscriber.Normally Monix's implementation guarantees that events are not emitted concurrently, and that the publisher MUST NOT emit the next event without acknowledgement from the consumer that it may proceed, however for badly behaved publishers, this wrapper provides the guarantee that the downstream Observer given in
subscribe
will not receive concurrent events.WARNING: if the buffer created by this operator is unbounded, it can blow up the process if the data source is pushing events faster than what the observer can consume, as it introduces an asynchronous boundary that eliminates the back-pressure requirements of the data source. Unbounded is the default overflowStrategy, see OverflowStrategy for options.
- overflowStrategy
- the overflow strategy used for buffering, which specifies what to do in case we're dealing with a slow consumer - should an unbounded buffer be used, should back-pressure be applied, should the pipeline drop newer or older events, should it drop the whole buffer? See OverflowStrategy for more details.
-
def
bufferIntrospective(maxSize: Int): Self[List[A]]
Buffers signals while busy, after which it emits the buffered events as a single bundle.
Buffers signals while busy, after which it emits the buffered events as a single bundle.
This operator starts applying back-pressure when the underlying buffer's size is exceeded.
-
def
bufferSliding(count: Int, skip: Int): Self[Seq[A]]
Returns an observable that emits buffers of items it collects from the source observable.
Returns an observable that emits buffers of items it collects from the source observable. The resulting observable emits buffers every
skip
items, each containingcount
items.If the source observable completes, then the current buffer gets signaled downstream. If the source triggers an error then the current buffer is being dropped and the error gets propagated immediately.
For
count
andskip
there are 3 possibilities:- in case
skip == count
, then there are no items dropped and no overlap, the call being equivalent tobuffer(count)
- in case
skip < count
, then overlap between buffers happens, with the number of elements being repeated beingcount - skip
- in case
skip > count
, thenskip - count
elements start getting dropped between windows
- count
the maximum size of each buffer before it should be emitted
- skip
how many items emitted by the source observable should be skipped before starting a new buffer. Note that when skip and count are equal, this is the same operation as
buffer(count)
- in case
-
def
bufferTimed(timespan: FiniteDuration): Self[Seq[A]]
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time.
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time.
This version of
buffer
emits a new bundle of items periodically, every timespan amount of time, containing all items emitted by the source Observable since the previous bundle emission.If the source observable completes, then the current buffer gets signaled downstream. If the source triggers an error then the current buffer is being dropped and the error gets propagated immediately.
- timespan
the interval of time at which it should emit the buffered bundle
-
def
bufferTimedAndCounted(timespan: FiniteDuration, maxCount: Int): Self[Seq[A]]
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time.
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time.
The resulting observable emits connected, non-overlapping buffers, each of a fixed duration specified by the
timespan
argument or a maximum size specified by themaxCount
argument (whichever is reached first).If the source observable completes, then the current buffer gets signaled downstream. If the source triggers an error then the current buffer is being dropped and the error gets propagated immediately.
- timespan
the interval of time at which it should emit the buffered bundle
- maxCount
is the maximum bundle size, after which the buffered bundle gets forcefully emitted
-
def
bufferTimedWithPressure(period: FiniteDuration, maxSize: Int): Self[Seq[A]]
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time.
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time. Back-pressure the source when the buffer is full.
The resulting observable emits connected, non-overlapping buffers, each of a fixed duration specified by the
period
argument.The bundles are emitted at a fixed rate. If the source is silent, then the resulting observable will start emitting empty sequences.
If the source observable completes, then the current buffer gets signaled downstream. If the source triggers an error then the current buffer is being dropped and the error gets propagated immediately.
A
maxSize
argument is specified as the capacity of the bundle. In case the source is too fast andmaxSize
is reached, then the source will be back-pressured.The difference with bufferTimedAndCounted is that bufferTimedWithPressure applies back-pressure from the time when the buffer is full until the buffer is emitted, whereas bufferTimedAndCounted will forcefully emit the buffer when it's full.
- period
the interval of time at which it should emit the buffered bundle
- maxSize
is the maximum buffer size, after which the source starts being back-pressured
-
def
bufferTumbling(count: Int): Self[Seq[A]]
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time.
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time. This version of
buffer
is emitting items once the internal buffer has reached the given count.If the source observable completes, then the current buffer gets signaled downstream. If the source triggers an error then the current buffer is being dropped and the error gets propagated immediately.
- count
the maximum size of each buffer before it should be emitted
-
def
bufferWithSelector[S](selector: Observable[S], maxSize: Int): Self[Seq[A]]
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time, whenever the
selector
observable signals an event.Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time, whenever the
selector
observable signals an event.The resulting observable collects the elements of the source in a buffer and emits that buffer whenever the given
selector
observable emits anonNext
event, when the buffer is emitted as a sequence downstream and then reset. Thus the resulting observable emits connected, non-overlapping bundles triggered by the givenselector
.If
selector
terminates with anonComplete
, then the resulting observable also terminates normally. Ifselector
terminates with anonError
, then the resulting observable also terminates with an error.If the source observable completes, then the current buffer gets signaled downstream. If the source triggers an error then the current buffer is being dropped and the error gets propagated immediately.
A
maxSize
argument is specified as the capacity of the bundle. In case the source is too fast andmaxSize
is reached, then the source will be back-pressured.- selector
is the observable that triggers the signaling of the current buffer
- maxSize
is the maximum bundle size, after which the source starts being back-pressured
-
def
bufferWithSelector[S](selector: Observable[S]): Self[Seq[A]]
Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time, whenever the
selector
observable signals an event.Periodically gather items emitted by an observable into bundles and emit these bundles rather than emitting the items one at a time, whenever the
selector
observable signals an event.The resulting observable collects the elements of the source in a buffer and emits that buffer whenever the given
selector
observable emits anonNext
event, when the buffer is emitted as a sequence downstream and then reset. Thus the resulting observable emits connected, non-overlapping bundles triggered by the givenselector
.If
selector
terminates with anonComplete
, then the resulting observable also terminates normally. Ifselector
terminates with anonError
, then the resulting observable also terminates with an error.If the source observable completes, then the current buffer gets signaled downstream. If the source triggers an error then the current buffer is being dropped and the error gets propagated immediately.
- selector
is the observable that triggers the signaling of the current buffer
-
def
clone(): AnyRef
- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @native() @throws( ... )
-
def
collect[B](pf: PartialFunction[A, B]): Self[B]
Applies the given partial function to the source for each element for which the given partial function is defined.
Applies the given partial function to the source for each element for which the given partial function is defined.
- pf
the function that filters and maps the source
- returns
an observable that emits the transformed items by the given partial function
-
def
combineLatest[B](other: Observable[B]): Self[(A, B)]
Creates a new observable from the source and another given observable, by emitting elements combined in pairs.
Creates a new observable from the source and another given observable, by emitting elements combined in pairs. If one of the observables emits fewer events than the other, then the rest of the unpaired events are ignored.
See zip for an alternative that pairs the items in strict sequence.
- other
is an observable that gets paired with the source
-
def
combineLatestMap[B, R](other: Observable[B])(f: (A, B) ⇒ R): Self[R]
Creates a new observable from the source and another given observable, by emitting elements combined in pairs.
Creates a new observable from the source and another given observable, by emitting elements combined in pairs. If one of the observables emits fewer events than the other, then the rest of the unpaired events are ignored.
See zipMap for an alternative that pairs the items in strict sequence.
- other
is an observable that gets paired with the source
- f
is a mapping function over the generated pairs
-
def
completed: Self[Nothing]
Ignores all items emitted by the source Observable and only calls onCompleted or onError.
Ignores all items emitted by the source Observable and only calls onCompleted or onError.
- returns
an empty Observable that only calls onCompleted or onError, based on which one is called by the source Observable
-
def
concat[B](implicit ev: <:<[A, Observable[B]]): Self[B]
Concatenates the sequence of observables emitted by the source into one observable, without any transformation.
Concatenates the sequence of observables emitted by the source into one observable, without any transformation.
You can combine the items emitted by multiple observables so that they act like a single sequence by using this operator.
The difference between the
concat
operation andmerge
is thatconcat
cares about the ordering of sequences (e.g. all items emitted by the first observable in the sequence will come before the elements emitted by the second observable), whereasmerge
doesn't care about that (elements get emitted as they come). Because of back-pressure applied to observables,concat
is safe to use in all contexts, whereasmerge
requires buffering.- returns
an observable that emits items that are the result of flattening the items emitted by the observables emitted by the source
-
def
concatDelayErrors[B](implicit ev: <:<[A, Observable[B]]): Self[B]
Concatenates the sequence of observables emitted by the source into one observable, without any transformation.
Concatenates the sequence of observables emitted by the source into one observable, without any transformation.
You can combine the items emitted by multiple observables so that they act like a single sequence by using this operator.
The difference between the
concat
operation andmerge
is thatconcat
cares about the ordering of sequences (e.g. all items emitted by the first observable in the sequence will come before the elements emitted by the second observable), whereasmerge
doesn't care about that (elements get emitted as they come). Because of back-pressure applied to observables,concat
is safe to use in all contexts, whereasmerge
requires buffering.This version is reserving onError notifications until all of the observables complete and only then passing the issued errors(s) downstream. Note that the streamed error is a CompositeException, since multiple errors from multiple streams can happen.
- returns
an observable that emits items that are the result of flattening the items emitted by the observables emitted by the source
-
def
concatMap[B](f: (A) ⇒ Observable[B]): Self[B]
Applies a function that you supply to each item emitted by the source observable, where that function returns observables, and then concatenating those resulting sequences and emitting the results of this concatenation.
Applies a function that you supply to each item emitted by the source observable, where that function returns observables, and then concatenating those resulting sequences and emitting the results of this concatenation.
The difference between the
concat
operation andmerge
is thatconcat
cares about the ordering of sequences (e.g. all items emitted by the first observable in the sequence will come before the elements emitted by the second observable), whereasmerge
doesn't care about that (elements get emitted as they come). Because of back-pressure applied to observables,concat
is safe to use in all contexts, whereasmerge
requires buffering. -
def
concatMapDelayErrors[B](f: (A) ⇒ Observable[B]): Self[B]
Applies a function that you supply to each item emitted by the source observable, where that function returns sequences and then concatenating those resulting sequences and emitting the results of this concatenation.
Applies a function that you supply to each item emitted by the source observable, where that function returns sequences and then concatenating those resulting sequences and emitting the results of this concatenation.
This version is reserving onError notifications until all of the observables complete and only then passing the issued errors(s) downstream. Note that the streamed error is a CompositeException, since multiple errors from multiple streams can happen.
- f
a function that, when applied to an item emitted by the source, returns an observable
- returns
an observable that emits items that are the result of flattening the items emitted by the observables emitted by the source
-
def
countF: Self[Long]
Creates a new Observable that emits the total number of
onNext
events that were emitted by the source.Creates a new Observable that emits the total number of
onNext
events that were emitted by the source.Note that this Observable emits only one item after the source is complete. And in case the source emits an error, then only that error will be emitted.
-
def
debounce(timeout: FiniteDuration): Self[A]
Only emit an item from an observable if a particular timespan has passed without it emitting another item.
Only emit an item from an observable if a particular timespan has passed without it emitting another item.
Note: If the source observable keeps emitting items more frequently than the length of the time window, then no items will be emitted by the resulting observable.
- timeout
the length of the window of time that must pass after the emission of an item from the source observable in which that observable emits no items in order for the item to be emitted by the resulting observable
- See also
echoOnce for a similar operator that also mirrors the source observable
-
def
debounceRepeated(period: FiniteDuration): Self[A]
Emits the last item from the source Observable if a particular timespan has passed without it emitting another item, and keeps emitting that item at regular intervals until the source breaks the silence.
Emits the last item from the source Observable if a particular timespan has passed without it emitting another item, and keeps emitting that item at regular intervals until the source breaks the silence.
So compared to regular debounceTo this version keeps emitting the last item of the source.
Note: If the source Observable keeps emitting items more frequently than the length of the time window then no items will be emitted by the resulting Observable.
- period
the length of the window of time that must pass after the emission of an item from the source Observable in which that Observable emits no items in order for the item to be emitted by the resulting Observable at regular intervals, also determined by period
- See also
echoRepeated for a similar operator that also mirrors the source observable
-
def
debounceTo[B](timeout: FiniteDuration, f: (A) ⇒ Observable[B]): Self[B]
Doesn't emit anything until a
timeout
period passes without the source emitting anything.Doesn't emit anything until a
timeout
period passes without the source emitting anything. When that timeout happens, we subscribe to the observable generated by the given function, an observable that will keep emitting until the source will break the silence by emitting another event.Note: If the source observable keeps emitting items more frequently than the length of the time window, then no items will be emitted by the resulting Observable.
- timeout
the length of the window of time that must pass after the emission of an item from the source Observable in which that Observable emits no items in order for the item to be emitted by the resulting Observable
- f
is a function that receives the last element generated by the source, generating an observable to be subscribed when the source is timing out
-
def
defaultIfEmpty[B >: A](default: ⇒ B): Self[B]
Emit items from the source, or emit a default item if the source completes after emitting no items.
-
def
delayOnComplete(delay: FiniteDuration): Self[A]
Delays emitting the final
onComplete
event by the specified amount. -
def
delayOnNext(duration: FiniteDuration): Self[A]
Returns an Observable that emits the items emitted by the source Observable shifted forward in time by a specified delay.
Returns an Observable that emits the items emitted by the source Observable shifted forward in time by a specified delay.
Each time the source Observable emits an item, delay starts a timer, and when that timer reaches the given duration, the Observable returned from delay emits the same item.
NOTE: this delay refers strictly to the time between the
onNext
event coming from our source and the time it takes the downstream observer to get this event. On the other hand the operator is also applying back-pressure, so on slow observers the actual time passing between two successive events may be higher than the specifiedduration
.- duration
- the delay to shift the source by
- returns
the source Observable shifted in time by the specified delay
-
def
delayOnNextBySelector[B](selector: (A) ⇒ Observable[B]): Self[A]
Returns an Observable that emits the items emitted by the source Observable shifted forward in time.
Returns an Observable that emits the items emitted by the source Observable shifted forward in time.
This variant of
delay
sets its delay duration on a per-item basis by passing each item from the source Observable into a function that returns an Observable and then monitoring those Observables. When any such Observable emits an item or completes, the Observable returned by delay emits the associated item.- selector
is a function that returns an Observable for each item emitted by the source Observable, which is then used to delay the emission of that item by the resulting Observable until the Observable returned from
selector
emits an item- returns
the source Observable shifted in time by the specified delay
-
def
delaySubscription(timespan: FiniteDuration): Self[A]
Hold an Observer's subscription request for a specified amount of time before passing it on to the source Observable.
Hold an Observer's subscription request for a specified amount of time before passing it on to the source Observable.
- timespan
is the time to wait before the subscription is being initiated.
-
def
delaySubscriptionWith(trigger: Observable[Any]): Self[A]
Hold an Observer's subscription request until the given
trigger
observable either emits an item or completes, before passing it on to the source Observable.Hold an Observer's subscription request until the given
trigger
observable either emits an item or completes, before passing it on to the source Observable.If the given
trigger
completes in error, then the subscription is terminated withonError
.- trigger
the observable that must either emit an item or complete in order for the source to be subscribed.
-
def
dematerialize[B](implicit ev: <:<[A, Notification[B]]): Self[B]
Converts the source Observable that emits
Notification[A]
(the result of materialize) back to an Observable that emitsA
. -
def
distinct: Self[A]
Suppress the duplicate elements emitted by the source Observable.
Suppress the duplicate elements emitted by the source Observable.
WARNING: this requires unbounded buffering.
-
def
distinctByKey[K](key: (A) ⇒ K): Self[A]
Given a function that returns a key for each element emitted by the source Observable, suppress duplicates items.
Given a function that returns a key for each element emitted by the source Observable, suppress duplicates items.
WARNING: this requires unbounded buffering.
-
def
distinctUntilChanged: Self[A]
Suppress duplicate consecutive items emitted by the source Observable
-
def
distinctUntilChangedByKey[K](key: (A) ⇒ K): Self[A]
Suppress duplicate consecutive items emitted by the source Observable
-
def
doAfterSubscribe(cb: () ⇒ Unit): Self[A]
Executes the given callback just after the subscription happens.
Executes the given callback just after the subscription happens.
- See also
doOnSubscribe for executing a callback just before a subscription happens.
-
def
doAfterTerminate(cb: (Option[Throwable]) ⇒ Unit): Self[A]
Executes the given callback after the stream has ended either with an
onComplete
oronError
event, or when the streaming stops by a downstreamStop
being signaled.Executes the given callback after the stream has ended either with an
onComplete
oronError
event, or when the streaming stops by a downstreamStop
being signaled.This differs from doOnTerminate in that this happens *after* the
onComplete
oronError
notification.- See also
doAfterTerminateEval for a version that allows for asynchronous evaluation by means of Task.
-
def
doAfterTerminateEval(cb: (Option[Throwable]) ⇒ Task[Unit]): Self[A]
Evaluates the task generated by the given callback after the stream has ended either with an
onComplete
oronError
event, or when the streaming stops by a downstreamStop
being signaled.Evaluates the task generated by the given callback after the stream has ended either with an
onComplete
oronError
event, or when the streaming stops by a downstreamStop
being signaled.This operation subsumes doOnEarlyStopEval and the callback-generated Task will back-pressure the source when applied for
Stop
events returned byonNext
and thus the upstream source will receive theStop
result only after the task has finished executing.This differs from doOnTerminateEval in that this happens *after* the
onComplete
oronError
notification.- See also
doAfterTerminate for a simpler version that doesn't allow asynchronous execution.
-
def
doOnComplete(cb: () ⇒ Unit): Self[A]
Executes the given callback when the stream has ended with an
onComplete
event, but before the complete event is emitted.Executes the given callback when the stream has ended with an
onComplete
event, but before the complete event is emitted.Unless you know what you're doing, you probably want to use doOnTerminate and doOnSubscriptionCancel for proper disposal of resources on completion.
- cb
the callback to execute when the
onComplete
event gets emitted
- See also
doOnCompleteEval for a version that allows for asynchronous evaluation by means of Task.
-
def
doOnCompleteEval(task: Task[Unit]): Self[A]
Evaluates the given task when the stream has ended with an
onComplete
event, but before the complete event is emitted.Evaluates the given task when the stream has ended with an
onComplete
event, but before the complete event is emitted.The task gets evaluated and is finished *before* the
onComplete
signal gets sent downstream.Unless you know what you're doing, you probably want to use doOnTerminateEval and doOnSubscriptionCancel for proper disposal of resources on completion.
- task
the task to execute when the
onComplete
event gets emitted
- See also
doOnComplete for a simpler version that doesn't do asynchronous execution
-
def
doOnEarlyStop(cb: () ⇒ Unit): Self[A]
Executes the given callback when the streaming is stopped due to a downstream Stop signal returned by onNext.
Executes the given callback when the streaming is stopped due to a downstream Stop signal returned by onNext.
- See also
doOnEarlyStopEval for a version that allows for asynchronous evaluation by means of Task.
-
def
doOnEarlyStopEval(task: Task[Unit]): Self[A]
Executes the given task when the streaming is stopped due to a downstream Stop signal returned by onNext.
Executes the given task when the streaming is stopped due to a downstream Stop signal returned by onNext.
The given
task
gets evaluated *before* the upstream receives theStop
event (is back-pressured).- See also
doOnEarlyStop for a simpler version that doesn't do asynchronous execution
-
def
doOnError(cb: (Throwable) ⇒ Unit): Self[A]
Executes the given callback when the stream is interrupted with an error, before the
onError
event is emitted downstream.Executes the given callback when the stream is interrupted with an error, before the
onError
event is emitted downstream.NOTE: should protect the code in this callback, because if it throws an exception the
onError
event will prefer signaling the original exception and otherwise the behavior is undefined.- See also
doOnTerminate and doOnSubscriptionCancel for handling resource disposal, also see doOnErrorEval for a version that does asynchronous evaluation by means of Task.
-
def
doOnErrorEval(cb: (Throwable) ⇒ Task[Unit]): Self[A]
Executes the given task when the stream is interrupted with an error, before the
onError
event is emitted downstream.Executes the given task when the stream is interrupted with an error, before the
onError
event is emitted downstream.NOTE: should protect the code in this callback, because if it throws an exception the
onError
event will prefer signaling the original exception and otherwise the behavior is undefined.- See also
doOnTerminateEval and doOnSubscriptionCancel for handling resource disposal, also see doOnError for a simpler version that doesn't do asynchronous execution.
-
def
doOnNext(cb: (A) ⇒ Unit): Self[A]
Executes the given callback for each element generated by the source Observable, useful for doing side-effects.
Executes the given callback for each element generated by the source Observable, useful for doing side-effects.
- returns
a new Observable that executes the specified callback for each element
- See also
doOnNextEval for a version that allows for asynchronous evaluation by means of Task.
-
def
doOnNextAck(cb: (A, Ack) ⇒ Unit): Self[A]
Executes the given callback on each acknowledgement received from the downstream subscriber.
Executes the given callback on each acknowledgement received from the downstream subscriber.
This method helps in executing logic after messages get processed, for example when messages are polled from some distributed message queue and an acknowledgement needs to be sent after each message in order to mark it as processed.
- See also
doOnNextAckEval for a version that allows for asynchronous evaluation by means of Task.
-
def
doOnNextAckEval(cb: (A, Ack) ⇒ Task[Unit]): Self[A]
Executes the given callback on each acknowledgement received from the downstream subscriber, executing a generated Task and back-pressuring until the task is done.
Executes the given callback on each acknowledgement received from the downstream subscriber, executing a generated Task and back-pressuring until the task is done.
This method helps in executing logic after messages get processed, for example when messages are polled from some distributed message queue and an acknowledgement needs to be sent after each message in order to mark it as processed.
- See also
doOnNextAck for a simpler version that doesn't allow asynchronous execution.
-
def
doOnNextEval(cb: (A) ⇒ Task[Unit]): Self[A]
Evaluates the given callback for each element generated by the source Observable, useful for triggering async side-effects.
Evaluates the given callback for each element generated by the source Observable, useful for triggering async side-effects.
- returns
a new Observable that executes the specified callback for each element
- See also
doOnNext for a simpler version that doesn't allow asynchronous execution.
-
def
doOnStart(cb: (A) ⇒ Unit): Self[A]
Executes the given callback only for the first element generated by the source Observable, useful for doing a piece of computation only when the stream starts.
Executes the given callback only for the first element generated by the source Observable, useful for doing a piece of computation only when the stream starts.
- returns
a new Observable that executes the specified callback only for the first element
-
def
doOnSubscribe(cb: () ⇒ Unit): Self[A]
Executes the given callback just before the subscription happens.
Executes the given callback just before the subscription happens.
- See also
doAfterSubscribe for executing a callback just after a subscription happens.
-
def
doOnSubscriptionCancel(cb: () ⇒ Unit): Self[A]
Executes the given callback when the connection is being cancelled.
-
def
doOnTerminate(cb: (Option[Throwable]) ⇒ Unit): Self[A]
Executes the given callback right before the streaming is ended either with an
onComplete
oronError
event, or when the streaming stops by a downstreamStop
being signaled.Executes the given callback right before the streaming is ended either with an
onComplete
oronError
event, or when the streaming stops by a downstreamStop
being signaled.It is the equivalent of calling:
This differs from doAfterTerminate in that this happens *before* the
onComplete
oronError
notification.- See also
doOnTerminateEval for a version that allows for asynchronous evaluation by means of Task.
-
def
doOnTerminateEval(cb: (Option[Throwable]) ⇒ Task[Unit]): Self[A]
Evaluates the task generated by the given callback right before the streaming is ended either with an
onComplete
oronError
event, or when the streaming stops by a downstreamStop
being signaled.Evaluates the task generated by the given callback right before the streaming is ended either with an
onComplete
oronError
event, or when the streaming stops by a downstreamStop
being signaled.The callback-generated Task will back-pressure the source when applied for
Stop
events returned byonNext
and thus the upstream source will receive theStop
result only after the task has finished executing.It is the equivalent of calling:
This differs from doAfterTerminateEval in that this happens *before* the
onComplete
oronError
notification.- See also
doOnTerminate for a simpler version that doesn't allow asynchronous execution.
-
def
drop(n: Int): Self[A]
Drops the first
n
elements (from the start).Drops the first
n
elements (from the start).- n
the number of elements to drop
- returns
a new Observable that drops the first n elements emitted by the source
-
def
dropByTimespan(timespan: FiniteDuration): Self[A]
Creates a new observable that drops the events of the source, only for the specified
timestamp
window.Creates a new observable that drops the events of the source, only for the specified
timestamp
window.- timespan
the window of time during which the new observable must drop events emitted by the source
-
def
dropLast(n: Int): Self[A]
Drops the last
n
elements (from the end).Drops the last
n
elements (from the end).- n
the number of elements to drop
- returns
a new Observable that drops the first n elements emitted by the source
-
def
dropUntil(trigger: Observable[Any]): Self[A]
Discard items emitted by the source until a second observable emits an item or completes.
Discard items emitted by the source until a second observable emits an item or completes.
If the
trigger
observable completes in error, then the resulting observable will also end in error when it notices it (next time an element is emitted by the source).- trigger
the observable that has to emit an item before the source begin to be mirrored by the resulting observable
-
def
dropWhile(p: (A) ⇒ Boolean): Self[A]
Drops the longest prefix of elements that satisfy the given predicate and returns a new observable that emits the rest.
-
def
dropWhileWithIndex(p: (A, Int) ⇒ Boolean): Self[A]
Drops the longest prefix of elements that satisfy the given function and returns a new observable that emits the rest.
Drops the longest prefix of elements that satisfy the given function and returns a new observable that emits the rest. In comparison with dropWhile, this version accepts a function that takes an additional parameter: the zero-based index of the element.
-
def
dump(prefix: String, out: PrintStream = System.out): Self[A]
Utility that can be used for debugging purposes.
-
def
echoOnce(timeout: FiniteDuration): Self[A]
Mirror the source observable as long as the source keeps emitting items, otherwise if
timeout
passes without the source emitting anything new then the observable will emit the last item.Mirror the source observable as long as the source keeps emitting items, otherwise if
timeout
passes without the source emitting anything new then the observable will emit the last item.This is the rough equivalent of:
Observable.merge(source, source.debounce(period))
Note: If the source Observable keeps emitting items more frequently than the length of the time window then the resulting observable will mirror the source exactly.
- timeout
the window of silence that must pass in order for the observable to echo the last item
-
def
echoRepeated(timeout: FiniteDuration): Self[A]
Mirror the source observable as long as the source keeps emitting items, otherwise if
timeout
passes without the source emitting anything new then the observable will start emitting the last item repeatedly.Mirror the source observable as long as the source keeps emitting items, otherwise if
timeout
passes without the source emitting anything new then the observable will start emitting the last item repeatedly.Note: If the source Observable keeps emitting items more frequently than the length of the time window then the resulting observable will mirror the source exactly.
- timeout
the window of silence that must pass in order for the observable to start echoing the last item
-
def
endWith[B >: A](elems: Seq[B]): Self[B]
Creates a new Observable that emits the events of the source and then it also emits the given elements (appended to the stream).
-
def
endWithError(error: Throwable): Self[A]
Emits the given exception instead of
onComplete
.Emits the given exception instead of
onComplete
.- error
the exception to emit onComplete
- returns
a new Observable that emits an exception onComplete
-
final
def
eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
def
equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
executeOn(scheduler: Scheduler): Self[A]
Specify an override for the Scheduler that will be used for subscribing and for observing the source.
Specify an override for the Scheduler that will be used for subscribing and for observing the source.
Normally the Scheduler gets injected implicitly when doing
subscribe
, but this operator overrides the injected subscriber for the given source. And if the source is normally using that injected scheduler (given bysubscribe
), then the effect will be that all processing will now happen on the override.To put it in other words, in Monix it's usually the consumer and not the producer that specifies the scheduler and this operator allows for a different behavior.
This operator also includes the effects of subscribeOn, meaning that the subscription logic itself will start on the provided scheduler.
IMPORTANT: This operator is a replacement for the observeOn operator from ReactiveX, but does not work in the same way. The
observeOn
operator forces the signaling to happen on a givenScheduler
, butexecuteOn
is more relaxed, usage is not forced, the source just gets injected with a different scheduler and it's up to the source to actually use it. This also means the effects are more far reaching, because the whole chain until the call of this operator is affected.Alias for Observable.fork(fa, scheduler).
-
def
executeWithFork: Self[A]
Mirrors the source observable, but upon subscription ensure that the evaluation forks into a separate (logical) thread.
Mirrors the source observable, but upon subscription ensure that the evaluation forks into a separate (logical) thread.
The execution is managed by the injected scheduler in
subscribe()
.Alias for Observable.fork(fa).
-
def
executeWithModel(em: ExecutionModel): Self[A]
Returns a new observable that will execute the source with a different ExecutionModel.
Returns a new observable that will execute the source with a different ExecutionModel.
This allows fine-tuning the options injected by the scheduler locally. Example:
observable.executeWithModel(AlwaysAsyncExecution)
- em
is the ExecutionModel that will be used when evaluating the source.
-
def
existsF(p: (A) ⇒ Boolean): Self[Boolean]
Returns an Observable which emits a single value, either true, in case the given predicate holds for at least one item, or false otherwise.
Returns an Observable which emits a single value, either true, in case the given predicate holds for at least one item, or false otherwise.
- p
is a function that evaluates the items emitted by the source Observable, returning
true
if they pass the filter- returns
an Observable that emits only true or false in case the given predicate holds or not for at least one item
-
def
failed: Self[Throwable]
Returns an observable that emits a single Throwable, in case an error was thrown by the source, otherwise it isn't going to emit anything.
-
def
filter(p: (A) ⇒ Boolean): Self[A]
Only emits those items for which the given predicate holds.
Only emits those items for which the given predicate holds.
- p
a function that evaluates the items emitted by the source returning
true
if they pass the filter- returns
a new observable that emits only those items in the source for which the filter evaluates as
true
-
def
finalize(): Unit
- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
-
def
findF(p: (A) ⇒ Boolean): Self[A]
Returns an Observable which only emits the first item for which the predicate holds.
Returns an Observable which only emits the first item for which the predicate holds.
- p
is a function that evaluates the items emitted by the source Observable, returning
true
if they pass the filter- returns
an Observable that emits only the first item in the original Observable for which the filter evaluates as
true
-
def
firstOrElseF[B >: A](default: ⇒ B): Self[B]
Emits the first element emitted by the source, or otherwise if the source is completed without emitting anything, then the
default
is emitted.Emits the first element emitted by the source, or otherwise if the source is completed without emitting anything, then the
default
is emitted.Alias for
headOrElse
. -
def
flatMap[B](f: (A) ⇒ Observable[B]): Self[B]
Applies a function that you supply to each item emitted by the source observable, where that function returns sequences that can be observed, and then concatenating those resulting sequences and emitting the results of this concatenation.
Applies a function that you supply to each item emitted by the source observable, where that function returns sequences that can be observed, and then concatenating those resulting sequences and emitting the results of this concatenation.
Alias for concatMap.
The difference between the
concat
operation andmerge
is thatconcat
cares about the ordering of sequences (e.g. all items emitted by the first observable in the sequence will come before the elements emitted by the second observable), whereasmerge
doesn't care about that (elements get emitted as they come). Because of back-pressure applied to observables,concat
is safe to use in all contexts, whereasmerge
requires buffering. -
def
flatMapDelayErrors[B](f: (A) ⇒ Observable[B]): Self[B]
Applies a function that you supply to each item emitted by the source observable, where that function returns sequences and then concatenating those resulting sequences and emitting the results of this concatenation.
Applies a function that you supply to each item emitted by the source observable, where that function returns sequences and then concatenating those resulting sequences and emitting the results of this concatenation.
It's an alias for concatMapDelayErrors.
- f
a function that, when applied to an item emitted by the source Observable, returns an Observable
- returns
an Observable that emits the result of applying the transformation function to each item emitted by the source Observable and concatenating the results of the Observables obtained from this transformation.
-
def
flatMapLatest[B](f: (A) ⇒ Observable[B]): Self[B]
An alias of switchMap.
An alias of switchMap.
Returns a new observable that emits the items emitted by the observable most recently generated by the mapping function.
-
def
flatScan[R](initial: ⇒ R)(op: (R, A) ⇒ Observable[R]): Self[R]
Applies a binary operator to a start value and to elements produced by the source observable, going from left to right, producing and concatenating observables along the way.
-
def
flatScanDelayErrors[R](initial: ⇒ R)(op: (R, A) ⇒ Observable[R]): Self[R]
Applies a binary operator to a start value and to elements produced by the source observable, going from left to right, producing and concatenating observables along the way.
Applies a binary operator to a start value and to elements produced by the source observable, going from left to right, producing and concatenating observables along the way.
This version of flatScan delays all errors until
onComplete
, when it will finally emit a CompositeException. It's the combination between scan and flatMapDelayErrors. -
def
flatten[B](implicit ev: <:<[A, Observable[B]]): Self[B]
Concatenates the sequence of observables emitted by the source into one observable, without any transformation.
Concatenates the sequence of observables emitted by the source into one observable, without any transformation.
You can combine the items emitted by multiple observables so that they act like a single sequence by using this operator.
The difference between the
concat
operation andmerge
is thatconcat
cares about the ordering of sequences (e.g. all items emitted by the first observable in the sequence will come before the elements emitted by the second observable), whereasmerge
doesn't care about that (elements get emitted as they come). Because of back-pressure applied to observables,concat
is safe to use in all contexts, whereasmerge
requires buffering.Alias for concat.
- returns
an observable that emits items that are the result of flattening the items emitted by the observables emitted by the source
-
def
flattenDelayErrors[B](implicit ev: <:<[A, Observable[B]]): Self[B]
Alias for concatDelayErrors.
Alias for concatDelayErrors.
Concatenates the sequence of observables emitted by the source into one observable, without any transformation.
You can combine the items emitted by multiple observables so that they act like a single sequence by using this operator.
The difference between the
concat
operation andmerge
is thatconcat
cares about the ordering of sequences (e.g. all items emitted by the first observable in the sequence will come before the elements emitted by the second observable), whereasmerge
doesn't care about that (elements get emitted as they come). Because of back-pressure applied to observables,concat
is safe to use in all contexts, whereasmerge
requires buffering.This version is reserving onError notifications until all of the observables complete and only then passing the issued errors(s) downstream. Note that the streamed error is a CompositeException, since multiple errors from multiple streams can happen.
- returns
an observable that emits items that are the result of flattening the items emitted by the observables emitted by the source
-
def
flattenLatest[B](implicit ev: <:<[A, Observable[B]]): Self[B]
Alias for switch
Alias for switch
Convert an observable that emits observables into a single observable that emits the items emitted by the most-recently-emitted of those observables.
-
def
foldLeftF[R](initial: ⇒ R)(op: (R, A) ⇒ R): Self[R]
Applies a binary operator to a start value and all elements of this Observable, going left to right and returns a new Observable that emits only one item before
onComplete
.Applies a binary operator to a start value and all elements of this Observable, going left to right and returns a new Observable that emits only one item before
onComplete
.- initial
is the initial state, specified as a possibly lazy value; it gets evaluated when the subscription happens and if it triggers an error then the subscriber will get immediately terminated with an error
- op
is an operator that will fold the signals of the source observable, returning the next state
-
def
foldWhileF[R](initial: ⇒ R)(op: (R, A) ⇒ (Boolean, R)): Self[R]
Folds the source observable, from start to finish, until the source completes, or until the operator short-circuits the process by returning
false
.Folds the source observable, from start to finish, until the source completes, or until the operator short-circuits the process by returning
false
.Note that a call to foldLeftF is equivalent to this function being called with an operator always returning
true
as the first member of its result.- initial
is the initial state, specified as a possibly lazy value; it gets evaluated when the subscription happens and if it triggers an error then the subscriber will get immediately terminated with an error
- op
is an operator that will fold the signals of the source observable, returning either a new state along with a boolean that should become false in case the folding must be interrupted.
-
def
forAllF(p: (A) ⇒ Boolean): Self[Boolean]
Returns an Observable that emits a single boolean, either true, in case the given predicate holds for all the items emitted by the source, or false in case at least one item is not verifying the given predicate.
Returns an Observable that emits a single boolean, either true, in case the given predicate holds for all the items emitted by the source, or false in case at least one item is not verifying the given predicate.
- p
is a function that evaluates the items emitted by the source Observable, returning
true
if they pass the filter- returns
an Observable that emits only true or false in case the given predicate holds or not for all the items
-
final
def
getClass(): Class[_]
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
-
def
groupBy[K](keySelector: (A) ⇒ K)(implicit keysBuffer: Synchronous[Nothing] = OverflowStrategy.Unbounded): Self[GroupedObservable[K, A]]
Groups the items emitted by an Observable according to a specified criterion, and emits these grouped items as GroupedObservables, one GroupedObservable per group.
Groups the items emitted by an Observable according to a specified criterion, and emits these grouped items as GroupedObservables, one GroupedObservable per group.
Note: A GroupedObservable will cache the items it is to emit until such time as it is subscribed to. For this reason, in order to avoid memory leaks, you should not simply ignore those GroupedObservables that do not concern you. Instead, you can signal to them that they may discard their buffers by doing something like
source.take(0)
.- keySelector
a function that extracts the key for each item
-
def
hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
-
def
headF: Self[A]
Only emits the first element emitted by the source observable, after which it's completed immediately.
-
def
headOrElseF[B >: A](default: ⇒ B): Self[B]
Emits the first element emitted by the source, or otherwise if the source is completed without emitting anything, then the
default
is emitted. -
def
ignoreElements: Self[Nothing]
Alias for completed.
Alias for completed. Ignores all items emitted by the source and only calls onCompleted or onError.
- returns
an empty sequence that only calls onCompleted or onError, based on which one is called by the source Observable
-
def
interleave[B >: A](other: Observable[B]): Self[B]
Creates a new observable from this observable and another given observable by interleaving their items into a strictly alternating sequence.
Creates a new observable from this observable and another given observable by interleaving their items into a strictly alternating sequence.
So the first item emitted by the new observable will be the item emitted by
self
, the second item will be emitted by the other observable, and so forth; when eitherself
orother
callsonCompletes
, the items will then be directly coming from the observable that has not completed; whenonError
is called by eitherself
orother
, the new observable will callonError
and halt.See merge for a more relaxed alternative that doesn't emit items in strict alternating sequence.
- other
is an observable that interleaves with the source
- returns
a new observable sequence that alternates emission of the items from both child streams
-
def
isEmptyF: Self[Boolean]
Returns an Observable that emits true if the source Observable is empty, otherwise false.
-
final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
def
lastF: Self[A]
Only emits the last element emitted by the source observable, after which it's completed immediately.
-
def
map[B](f: (A) ⇒ B): Self[B]
Returns a new observable that applies the given function to each item emitted by the source and emits the result.
-
def
mapAsync[B](parallelism: Int)(f: (A) ⇒ Task[B]): Self[B]
Given a mapping function that maps events to tasks, applies it in parallel on the source, but with a specified
parallelism
, which indicates the maximum number of tasks that can be executed in parallel.Given a mapping function that maps events to tasks, applies it in parallel on the source, but with a specified
parallelism
, which indicates the maximum number of tasks that can be executed in parallel.Similar in spirit with Consumer.loadBalance, but expressed as an operator that executes Task instances in parallel.
Note that when the specified
parallelism
is 1, it has the same behavior as mapTask.- parallelism
is the maximum number of tasks that can be executed in parallel, over which the source starts being back-pressured
- f
is the mapping function that produces tasks to execute in parallel, which will eventually produce events for the resulting observable stream
- See also
mapTask for serial execution
-
def
mapAsync[B](f: (A) ⇒ Task[B]): Self[B]
Alias for mapTask.
-
def
mapFuture[B](f: (A) ⇒ Future[B]): Self[B]
Maps elements from the source using a function that can do asynchronous processing by means of
scala.concurrent.Future
.Maps elements from the source using a function that can do asynchronous processing by means of
scala.concurrent.Future
.Given a source observable, this function is basically the equivalent of doing:
observable.concatMap(a => Observable.fromFuture(f(a)))
However prefer this operator to
concatMap
because it is more clear and has better performance. -
def
mapTask[B](f: (A) ⇒ Task[B]): Self[B]
Maps elements from the source using a function that can do asynchronous processing by means of Task.
Maps elements from the source using a function that can do asynchronous processing by means of Task.
Given a source observable, this function is basically the equivalent of doing:
observable.concatMap(a => Observable.fromTask(f(a)))
However prefer this operator to
concatMap
because it is more clear and has better performance.- See also
mapFuture for the version that can work with
scala.concurrent.Future
-
def
materialize: Self[Notification[A]]
Converts the source Observable that emits
A
into an Observable that emitsNotification[A]
. -
def
maxByF[B](f: (A) ⇒ B)(implicit ev: Ordering[B]): Self[A]
Takes the elements of the source Observable and emits the element that has the maximum key value, where the key is generated by the given function
f
. -
def
maxF[B >: A](implicit ev: Ordering[B]): Self[B]
Takes the elements of the source Observable and emits the maximum value, after the source has completed.
-
def
merge[B](implicit ev: <:<[A, Observable[B]], os: OverflowStrategy[B] = OverflowStrategy.Default): Self[B]
Merges the sequence of Observables emitted by the source into one Observable, without any transformation.
Merges the sequence of Observables emitted by the source into one Observable, without any transformation.
You can combine the items emitted by multiple Observables so that they act like a single Observable by using this operator.
- returns
an Observable that emits items that are the result of flattening the items emitted by the Observables emitted by
this
.
- Note
this operation needs to do buffering and by not specifying an OverflowStrategy, the default strategy is being used.
-
def
mergeDelayErrors[B](implicit ev: <:<[A, Observable[B]], os: OverflowStrategy[B] = OverflowStrategy.Default): Self[B]
Merges the sequence of Observables emitted by the source into one Observable, without any transformation.
Merges the sequence of Observables emitted by the source into one Observable, without any transformation.
You can combine the items emitted by multiple Observables so that they act like a single Observable by using this operator.
This version is reserving onError notifications until all of the observables complete and only then passing the issued errors(s) downstream. Note that the streamed error is a CompositeException, since multiple errors from multiple streams can happen.
- returns
an Observable that emits items that are the result of flattening the items emitted by the Observables emitted by
this
.
- Note
this operation needs to do buffering and by not specifying an OverflowStrategy, the default strategy is being used.
-
def
mergeMap[B](f: (A) ⇒ Observable[B])(implicit os: OverflowStrategy[B] = OverflowStrategy.Default): Self[B]
Creates a new observable by applying a function that you supply to each item emitted by the source observable, where that function returns an observable, and then merging those resulting observable and emitting the results of this merger.
Creates a new observable by applying a function that you supply to each item emitted by the source observable, where that function returns an observable, and then merging those resulting observable and emitting the results of this merger.
The difference between this and
concatMap
is thatconcatMap
cares about ordering of emitted items (e.g. all items emitted by the first observable in the sequence will come before the elements emitted by the second observable), whereasmerge
doesn't care about that (elements get emitted as they come). Because of back-pressure applied to observables, theconcat
operation is safe to use in all contexts, whereasmerge
requires buffering.- f
- the transformation function
- returns
an observable that emits the result of applying the transformation function to each item emitted by the source observable and merging the results of the observables obtained from this transformation.
-
def
mergeMapDelayErrors[B](f: (A) ⇒ Observable[B])(implicit os: OverflowStrategy[B] = OverflowStrategy.Default): Self[B]
Creates a new observable by applying a function that you supply to each item emitted by the source observable, where that function returns an observable, and then merging those resulting observable and emitting the results of this merger.
Creates a new observable by applying a function that you supply to each item emitted by the source observable, where that function returns an observable, and then merging those resulting observable and emitting the results of this merger.
The difference between this and
concatMap
is thatconcatMap
cares about ordering of emitted items (e.g. all items emitted by the first observable in the sequence will come before the elements emitted by the second observable), whereasmerge
doesn't care about that (elements get emitted as they come). Because of back-pressure applied to observables, theconcat
operation is safe to use in all contexts, whereasmerge
requires buffering.This version is reserving onError notifications until all of the observables complete and only then passing the issued errors(s) downstream. Note that the streamed error is a CompositeException, since multiple errors from multiple streams can happen.
- f
- the transformation function
- returns
an observable that emits the result of applying the transformation function to each item emitted by the source observable and merging the results of the observables obtained from this transformation.
-
def
minByF[B](f: (A) ⇒ B)(implicit ev: Ordering[B]): Self[A]
Takes the elements of the source Observable and emits the element that has the minimum key value, where the key is generated by the given function
f
. -
def
minF[B >: A](implicit ev: Ordering[B]): Self[B]
Takes the elements of the source Observable and emits the minimum value, after the source has completed.
-
final
def
ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
def
nonEmptyF: Self[Boolean]
Returns an Observable that emits false if the source Observable is empty, otherwise true.
-
final
def
notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
-
final
def
notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
-
def
observeOn[B >: A](s: Scheduler, os: OverflowStrategy[B]): Self[B]
Operator that specifies a different Scheduler, on which subscribers will observe events, instead of the default one.
Operator that specifies a different Scheduler, on which subscribers will observe events, instead of the default one.
This overloaded version of
observeOn
takes an extra OverflowStrategy parameter specifying the behavior of the underlying buffer.- s
is the alternative
Scheduler
reference to use for observing events- os
is the OverflowStrategy to apply to the underlying buffer
- See also
observeOn(Scheduler) for the version that does not take an
OverflowStrategy
parameter.
-
def
observeOn(s: Scheduler): Self[A]
Operator that specifies a different Scheduler, on which subscribers will observe events, instead of the default one.
Operator that specifies a different Scheduler, on which subscribers will observe events, instead of the default one.
An
Observable
with an appliedobserveOn
call will forward events into a buffer that uses the specifiedScheduler
reference to cycle through events and to makeonNext
calls to downstream listeners.Example:
import monix.execution.Scheduler val io = Scheduler.io("my-io") source.map(_ + 1) .observeOn(io) .foreach(x => println(x))
In the above example the first
map
(whatever comes before theobserveOn
call) gets executed using the defaultScheduler
(might execute on the current thread even), however theforeach
that's specified afterobserveOn
will get executed on the indicatedScheduler
.NOTE: this operator does not guarantee that downstream listeners will actually use the specified
Scheduler
to process events, because this depends on the rest of the pipeline. E.g. this will not work OK:source.observeOn(io).asyncBoundary(Unbounded)
This sample might not do what a user of
observeOn
would want. Indeed the implementation will use the providedio
reference for callingonNext
/onComplete
/onError
events, however because of the following asynchronous boundary created the actual listeners will probably end up being execute on a differentScheduler
.The underlying implementation uses a buffer to forward events. The OverflowStrategy being applied is the default one.
- s
is the alternative
Scheduler
reference to use for observing events
- See also
observeOn(Scheduler, OverflowStrategy) for the version that allows customizing the OverflowStrategy being used by the underlying buffer.
-
def
onCancelTriggerError: Self[A]
If the connection is cancelled then trigger a
CancellationException
.If the connection is cancelled then trigger a
CancellationException
.A connection can be cancelled with the help of the Cancelable returned on subscribe.
Because the cancellation is effectively concurrent with the signals the Observer receives and because we need to uphold the contract, this operator will effectively synchronize access to onNext, onComplete and onError. It will also watch out for asynchronous Stop events.
In other words, this operator does heavy synchronization, can prove to be inefficient and you should avoid using it because the signaled error can interfere with functionality from other operators that use cancellation internally and cancellation in general is a side-effecting operation that should be avoided, unless it's necessary.
-
def
onErrorFallbackTo[B >: A](that: Observable[B]): Self[B]
Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events continues with the specified backup sequence.Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events continues with the specified backup sequence.The created Observable mirrors the behavior of the source in case the source does not end with an error.
NOTE that compared with
onErrorResumeNext
from Rx.NET, the streaming is not resumed in case the source is terminated normally with anonComplete
.- that
is a backup sequence that's being subscribed in case the source terminates with an error.
-
def
onErrorHandle[B >: A](f: (Throwable) ⇒ B): Self[B]
Returns an observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events fallbacks to an observable emitting a single element generated by the backup function.Returns an observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events fallbacks to an observable emitting a single element generated by the backup function.See onErrorRecover for the version that takes a partial function as a parameter.
- f
- a function that matches errors with a backup element that is emitted when the source throws an error.
-
def
onErrorHandleWith[B >: A](f: (Throwable) ⇒ Observable[B]): Self[B]
Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events continues with the specified backup sequence generated by the given function.Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events continues with the specified backup sequence generated by the given function.See onErrorRecoverWith for the version that takes a partial function as a parameter.
- f
is a function that matches errors with a backup throwable that is subscribed when the source throws an error.
-
def
onErrorRecover[B >: A](pf: PartialFunction[Throwable, B]): Self[B]
Returns an observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events fallbacks to an observable emitting a single element generated by the backup function.Returns an observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events fallbacks to an observable emitting a single element generated by the backup function.The created Observable mirrors the behavior of the source in case the source does not end with an error or if the thrown
Throwable
is not matched.See onErrorHandle for the version that takes a total function as a parameter.
- pf
- a function that matches errors with a backup element that is emitted when the source throws an error.
-
def
onErrorRecoverWith[B >: A](pf: PartialFunction[Throwable, Observable[B]]): Self[B]
Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events continues with the specified backup sequence generated by the given function.Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case the streaming of events continues with the specified backup sequence generated by the given function.The created Observable mirrors the behavior of the source in case the source does not end with an error or if the thrown
Throwable
is not matched.See onErrorHandleWith for the version that takes a total function as a parameter.
- pf
is a function that matches errors with a backup throwable that is subscribed when the source throws an error.
-
def
onErrorRestart(maxRetries: Long): Self[A]
Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case it tries subscribing to the source again in the hope that it will complete without an error.Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case it tries subscribing to the source again in the hope that it will complete without an error.The number of retries is limited by the specified
maxRetries
parameter, so for an Observable that always ends in error the total number of subscriptions that will eventually happen ismaxRetries + 1
. -
def
onErrorRestartIf(p: (Throwable) ⇒ Boolean): Self[A]
Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case it tries subscribing to the source again in the hope that it will complete without an error.Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case it tries subscribing to the source again in the hope that it will complete without an error.The given predicate establishes if the subscription should be retried or not.
-
def
onErrorRestartUnlimited: Self[A]
Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case it tries subscribing to the source again in the hope that it will complete without an error.Returns an Observable that mirrors the behavior of the source, unless the source is terminated with an
onError
, in which case it tries subscribing to the source again in the hope that it will complete without an error.NOTE: The number of retries is unlimited, so something like
Observable.error(new RuntimeException).onErrorRestartUnlimited
will loop forever. -
def
pipeThrough[I >: A, B](pipe: Pipe[I, B]): Self[B]
Given a Pipe, transform the source observable with it.
-
def
pipeThroughSelector[S >: A, B, R](pipe: Pipe[S, B], f: (Observable[B]) ⇒ Observable[R]): Self[R]
Returns an observable that emits the results of invoking a specified selector on items emitted by a ConnectableObservable, which shares a single subscription to the underlying sequence.
Returns an observable that emits the results of invoking a specified selector on items emitted by a ConnectableObservable, which shares a single subscription to the underlying sequence.
- pipe
is the Pipe used to transform the source into a multicast (hot) observable that can be shared in the selector function
- f
is a selector function that can use the multicasted source sequence as many times as needed, without causing multiple subscriptions to the source sequence. Observers to the given source will receive all notifications of the source from the time of the subscription forward.
-
def
publishSelector[R](f: (Observable[A]) ⇒ Observable[R]): Self[R]
Returns an observable that emits the results of invoking a specified selector on items emitted by a ConnectableObservable, which shares a single subscription to the underlying sequence.
Returns an observable that emits the results of invoking a specified selector on items emitted by a ConnectableObservable, which shares a single subscription to the underlying sequence.
- f
is a selector function that can use the multicasted source sequence as many times as needed, without causing multiple subscriptions to the source sequence. Observers to the given source will receive all notifications of the source from the time of the subscription forward.
-
def
reduce[B >: A](op: (B, B) ⇒ B): Self[B]
Applies a binary operator to a start value and all elements of this Observable, going left to right and returns a new Observable that emits only one item before
onComplete
. -
def
repeat: Self[A]
Repeats the items emitted by the source continuously.
Repeats the items emitted by the source continuously. It caches the generated items until
onComplete
and repeats them forever.It terminates either on error or if the source is empty.
-
def
restartUntil(p: (A) ⇒ Boolean): Self[A]
Keeps restarting / resubscribing the source until the predicate returns
true
for the the first emitted element, after which it starts mirroring the source. -
def
sample(period: FiniteDuration): Self[A]
Emit the most recent items emitted by the source within periodic time intervals.
Emit the most recent items emitted by the source within periodic time intervals.
Use the
sample
operator to periodically look at an observable to see what item it has most recently emitted since the previous sampling. Note that if the source observable has emitted no items since the last time it was sampled, the observable that results from thesample
operator will emit no item for that sampling period.- period
the timespan at which sampling occurs
- See also
sampleRepeated for repeating the last value on silence
sampleBy for fine control
-
def
sampleBy[B](sampler: Observable[B]): Self[A]
Returns an observable that, when the specified sampler emits an item or completes, emits the most recently emitted item (if any) emitted by the source since the previous emission from the sampler.
Returns an observable that, when the specified sampler emits an item or completes, emits the most recently emitted item (if any) emitted by the source since the previous emission from the sampler.
Use the
sampleBy
operator to periodically look at an observable to see what item it has most recently emitted since the previous sampling. Note that if the source observable has emitted no items since the last time it was sampled, the observable that results from thesampleBy
operator will emit no item.- sampler
- the observable to use for sampling the source
- See also
sampleRepeatedBy for repeating the last value on silence
sample for periodic sampling
-
def
sampleRepeated(period: FiniteDuration): Self[A]
Emit the most recent items emitted by an observable within periodic time intervals.
Emit the most recent items emitted by an observable within periodic time intervals. If no new value has been emitted since the last time it was sampled, it signals the last emitted value anyway.
- period
the timespan at which sampling occurs
- See also
sampleRepeatedBy for fine control
sample for a variant that doesn't repeat the last value on silence
-
def
sampleRepeatedBy[B](sampler: Observable[B]): Self[A]
Returns an observable that, when the specified sampler observable emits an item or completes, emits the most recently emitted item (if any) emitted by the source Observable since the previous emission from the sampler observable.
Returns an observable that, when the specified sampler observable emits an item or completes, emits the most recently emitted item (if any) emitted by the source Observable since the previous emission from the sampler observable. If no new value has been emitted since the last time it was sampled, it signals the last emitted value anyway.
- sampler
- the Observable to use for sampling the source Observable
- See also
sampleRepeated for a periodic sampling
sampleBy for a variant that doesn't repeat the last value on silence
-
def
scan[R](initial: ⇒ R)(f: (R, A) ⇒ R): Self[R]
Applies a binary operator to a start value and all elements of this Observable, going left to right and returns a new Observable that emits on each step the result of the applied function.
Applies a binary operator to a start value and all elements of this Observable, going left to right and returns a new Observable that emits on each step the result of the applied function.
Similar to foldLeftF, but emits the state on each step. Useful for modeling finite state machines.
-
def
startWith[B >: A](elems: Seq[B]): Self[B]
Creates a new Observable that emits the given elements and then it also emits the events of the source (prepend operation).
-
def
subscribeOn(scheduler: Scheduler): Self[A]
Returns a new Observable that uses the specified
Scheduler
for initiating the subscription. -
def
sumF[B >: A](implicit arg0: Numeric[B]): Self[B]
Given a source that emits numeric values, the
sum
operator sums up all values and at onComplete it emits the total. -
def
switch[B](implicit ev: <:<[A, Observable[B]]): Self[B]
Convert an observable that emits observables into a single observable that emits the items emitted by the most-recently-emitted of those observables.
-
def
switchIfEmpty[B >: A](backup: Observable[B]): Self[B]
In case the source is empty, switch to the given backup.
-
def
switchMap[B](f: (A) ⇒ Observable[B]): Self[B]
Returns a new observable that emits the items emitted by the observable most recently generated by the mapping function.
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
tail: Self[A]
Drops the first element of the source observable, emitting the rest.
-
def
take(n: Long): Self[A]
Selects the first
n
elements (from the start).Selects the first
n
elements (from the start).- n
the number of elements to take
- returns
a new Observable that emits only the first
n
elements from the source
-
def
takeByTimespan(timespan: FiniteDuration): Self[A]
Creates a new Observable that emits the events of the source, only for the specified
timestamp
, after which it completes.Creates a new Observable that emits the events of the source, only for the specified
timestamp
, after which it completes.- timespan
the window of time during which the new Observable is allowed to emit the events of the source
-
def
takeEveryNth(n: Int): Self[A]
Creates a new Observable that emits every n-th event from the source, dropping intermediary events.
-
def
takeLast(n: Int): Self[A]
Creates a new observable that only emits the last
n
elements emitted by the source.Creates a new observable that only emits the last
n
elements emitted by the source.In case the source triggers an error, then the underlying buffer gets dropped and the error gets emitted immediately.
-
def
takeUntil(trigger: Observable[Any]): Self[A]
Creates a new observable that mirrors the source until the given
trigger
emits either an element oronComplete
, after which it is completed.Creates a new observable that mirrors the source until the given
trigger
emits either an element oronComplete
, after which it is completed.The resulting observable is completed as soon as
trigger
emits either anonNext
oronComplete
. Iftrigger
emits anonError
, then the resulting observable is also completed with error.- trigger
is an observable that will cancel the streaming as soon as it emits an event
-
def
takeWhile(p: (A) ⇒ Boolean): Self[A]
Takes longest prefix of elements that satisfy the given predicate and returns a new Observable that emits those elements.
-
def
takeWhileNotCanceled(c: BooleanCancelable): Self[A]
Takes longest prefix of elements that satisfy the given predicate and returns a new Observable that emits those elements.
-
def
throttleFirst(interval: FiniteDuration): Self[A]
Returns an Observable that emits only the first item emitted by the source Observable during sequential time windows of a specified duration.
Returns an Observable that emits only the first item emitted by the source Observable during sequential time windows of a specified duration.
This differs from Observable!.throttleLast in that this only tracks passage of time whereas
throttleLast
ticks at scheduled intervals.- interval
time to wait before emitting another item after emitting the last item
-
def
throttleLast(period: FiniteDuration): Self[A]
Emit the most recent items emitted by the source within periodic time intervals.
Emit the most recent items emitted by the source within periodic time intervals.
Alias for sample.
- period
duration of windows within which the last item emitted by the source Observable will be emitted
-
def
throttleWithTimeout(timeout: FiniteDuration): Self[A]
Only emit an item from an observable if a particular timespan has passed without it emitting another item.
Only emit an item from an observable if a particular timespan has passed without it emitting another item.
Note: If the source observable keeps emitting items more frequently than the length of the time window, then no items will be emitted by the resulting observable.
Alias for debounce.
- timeout
the length of the window of time that must pass after the emission of an item from the source observable in which that observable emits no items in order for the item to be emitted by the resulting observable
- See also
echoOnce for a similar operator that also mirrors the source observable
-
def
timeoutOnSlowDownstream(timeout: FiniteDuration): Self[A]
Returns an observable that mirrors the source but that will trigger a DownstreamTimeoutException in case the downstream subscriber takes more than the given timespan to process an
onNext
message.Returns an observable that mirrors the source but that will trigger a DownstreamTimeoutException in case the downstream subscriber takes more than the given timespan to process an
onNext
message.Note that this ignores the time it takes for the upstream to send
onNext
messages. For detecting slow producers see timeoutOnSlowUpstream.- timeout
maximum duration for
onNext
.
-
def
timeoutOnSlowUpstream(timeout: FiniteDuration): Self[A]
Returns an observable that mirrors the source but applies a timeout for each emitted item by the upstream.
Returns an observable that mirrors the source but applies a timeout for each emitted item by the upstream. If the next item isn't emitted within the specified timeout duration starting from its predecessor, the resulting Observable terminates and notifies observers of a TimeoutException.
Note that this ignores the time it takes to process
onNext
. If dealing with a slow consumer, see timeoutOnSlowDownstream.- timeout
maximum duration between emitted items before a timeout occurs (ignoring the time it takes to process
onNext
)
-
def
timeoutOnSlowUpstreamTo[B >: A](timeout: FiniteDuration, backup: Observable[B]): Self[B]
Returns an observable that mirrors the source but applies a timeout for each emitted item by the upstream.
Returns an observable that mirrors the source but applies a timeout for each emitted item by the upstream. If the next item isn't emitted within the specified timeout duration starting from its predecessor, the source is terminated and the downstream gets subscribed to the given backup.
Note that this ignores the time it takes to process
onNext
. If dealing with a slow consumer, see timeoutOnSlowDownstream.- timeout
maximum duration between emitted items before a timeout occurs (ignoring the time it takes to process
onNext
)- backup
is the alternative data source to subscribe to on timeout
-
def
toString(): String
- Definition Classes
- AnyRef → Any
-
final
def
wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @native() @throws( ... )
-
def
whileBusyBuffer[B >: A](overflowStrategy: Synchronous[B]): Self[B]
While the destination observer is busy, buffers events, applying the given overflowStrategy.
While the destination observer is busy, buffers events, applying the given overflowStrategy.
- overflowStrategy
- the overflow strategy used for buffering, which specifies what to do in case we're dealing with a slow consumer - should an unbounded buffer be used, should back-pressure be applied, should the pipeline drop newer or older events, should it drop the whole buffer? See OverflowStrategy for more details.
-
def
whileBusyDropEvents: Self[A]
While the destination observer is busy, drop the incoming events.
-
def
whileBusyDropEventsAndSignal[B >: A](onOverflow: (Long) ⇒ B): Self[B]
While the destination observer is busy, drop the incoming events.
While the destination observer is busy, drop the incoming events. When the downstream recovers, we can signal a special event meant to inform the downstream observer how many events where dropped.
- onOverflow
- a function that is used for signaling a special event used to inform the consumers that an overflow event happened, function that receives the number of dropped events as a parameter (see OverflowStrategy.Evicted)
-
def
withLatestFrom[B, R](other: Observable[B])(f: (A, B) ⇒ R): Self[R]
Combines the elements emitted by the source with the latest element emitted by another observable.
Combines the elements emitted by the source with the latest element emitted by another observable.
Similar with
combineLatest
, but only emits items when the single source emits an item (not when any of the Observables that are passed to the operator do, as combineLatest does).- other
is an observable that gets paired with the source
- f
is a mapping function over the generated pairs
-
def
withLatestFrom2[B1, B2, R](o1: Observable[B1], o2: Observable[B2])(f: (A, B1, B2) ⇒ R): Self[R]
Combines the elements emitted by the source with the latest elements emitted by two observables.
Combines the elements emitted by the source with the latest elements emitted by two observables.
Similar with
combineLatest
, but only emits items when the single source emits an item (not when any of the Observables that are passed to the operator do, as combineLatest does).- o1
is the first observable that gets paired with the source
- o2
is the second observable that gets paired with the source
- f
is a mapping function over the generated pairs
-
def
withLatestFrom3[B1, B2, B3, R](o1: Observable[B1], o2: Observable[B2], o3: Observable[B3])(f: (A, B1, B2, B3) ⇒ R): Self[R]
Combines the elements emitted by the source with the latest elements emitted by three observables.
Combines the elements emitted by the source with the latest elements emitted by three observables.
Similar with
combineLatest
, but only emits items when the single source emits an item (not when any of the Observables that are passed to the operator do, as combineLatest does).- o1
is the first observable that gets paired with the source
- o2
is the second observable that gets paired with the source
- o3
is the third observable that gets paired with the source
- f
is a mapping function over the generated pairs
-
def
withLatestFrom4[B1, B2, B3, B4, R](o1: Observable[B1], o2: Observable[B2], o3: Observable[B3], o4: Observable[B4])(f: (A, B1, B2, B3, B4) ⇒ R): Self[R]
Combines the elements emitted by the source with the latest elements emitted by four observables.
Combines the elements emitted by the source with the latest elements emitted by four observables.
Similar with
combineLatest
, but only emits items when the single source emits an item (not when any of the Observables that are passed to the operator do, as combineLatest does).- o1
is the first observable that gets paired with the source
- o2
is the second observable that gets paired with the source
- o3
is the third observable that gets paired with the source
- o4
is the fourth observable that gets paired with the source
- f
is a mapping function over the generated pairs
-
def
withLatestFrom5[B1, B2, B3, B4, B5, R](o1: Observable[B1], o2: Observable[B2], o3: Observable[B3], o4: Observable[B4], o5: Observable[B5])(f: (A, B1, B2, B3, B4, B5) ⇒ R): Self[R]
Combines the elements emitted by the source with the latest elements emitted by five observables.
Combines the elements emitted by the source with the latest elements emitted by five observables.
Similar with
combineLatest
, but only emits items when the single source emits an item (not when any of the Observables that are passed to the operator do, as combineLatest does).- o1
is the first observable that gets paired with the source
- o2
is the second observable that gets paired with the source
- o3
is the third observable that gets paired with the source
- o4
is the fourth observable that gets paired with the source
- o5
is the fifth observable that gets paired with the source
- f
is a mapping function over the generated pairs
-
def
withLatestFrom6[B1, B2, B3, B4, B5, B6, R](o1: Observable[B1], o2: Observable[B2], o3: Observable[B3], o4: Observable[B4], o5: Observable[B5], o6: Observable[B6])(f: (A, B1, B2, B3, B4, B5, B6) ⇒ R): Self[R]
Combines the elements emitted by the source with the latest elements emitted by six observables.
Combines the elements emitted by the source with the latest elements emitted by six observables.
Similar with
combineLatest
, but only emits items when the single source emits an item (not when any of the Observables that are passed to the operator do, as combineLatest does).- o1
is the first observable that gets paired with the source
- o2
is the second observable that gets paired with the source
- o3
is the third observable that gets paired with the source
- o4
is the fourth observable that gets paired with the source
- o5
is the fifth observable that gets paired with the source
- o6
is the sixth observable that gets paired with the source
- f
is a mapping function over the generated pairs
-
def
zip[B](other: Observable[B]): Self[(A, B)]
Creates a new observable from this observable and another given observable by combining their items in pairs in a strict sequence.
Creates a new observable from this observable and another given observable by combining their items in pairs in a strict sequence.
So the first item emitted by the new observable will be the tuple of the first items emitted by each of the source observables; the second item emitted by the new observable will be a tuple with the second items emitted by each of those observables; and so forth.
See combineLatest for a more relaxed alternative that doesn't combine items in strict sequence.
- other
is an observable that gets paired with the source
- returns
a new observable sequence that emits the paired items of the source observables
-
def
zipMap[B, R](other: Observable[B])(f: (A, B) ⇒ R): Self[R]
Creates a new observable from this observable and another given observable by combining their items in pairs in a strict sequence.
Creates a new observable from this observable and another given observable by combining their items in pairs in a strict sequence.
So the first item emitted by the new observable will be the result of the function applied to the first item emitted by each of the source observables; the second item emitted by the new observable will be the result of the function applied to the second item emitted by each of those observables; and so forth.
See combineLatestMap for a more relaxed alternative that doesn't combine items in strict sequence.
- other
is an observable that gets paired with the source
- f
is a mapping function over the generated pairs
-
def
zipWithIndex: Self[(A, Long)]
Zips the emitted elements of the source with their indices.
This is the API documentation for the Monix library.
Package Overview
monix.execution exposes lower level primitives for dealing with asynchronous execution:
Atomic
types, as alternative tojava.util.concurrent.atomic
monix.eval is for dealing with evaluation of results, thus exposing Task and Coeval.
monix.reactive exposes the
Observable
pattern:Observable
implementationsmonix.types implements type-class shims, to be translated to type-classes provided by libraries such as Cats or Scalaz.
monix.cats is the optional integration with the Cats library, providing translations for the types described in
monix.types
.monix.scalaz is the optional integration with the Scalaz library, providing translations for the types described in
monix.types
.