Class SubscribeWhen

Namespace

Bonsai.Reactive

Assembly

Bonsai.Core.dll

Represents an operator that subscribes to the first sequence only after the second sequence emits a notification.

The SubscribeWhen operator modifies the source sequence by waiting for the first value emitted by the second sequence before subscribing to the first sequence. This has the effect of delaying the start of the sequence until the second sequence emits a value.

SubscribeWhen can be used to control the timing of initialization. Note that if a source is hot, delaying the start of the sequence will not preserve past data.

Example

Use SubscribeWhen to start subscription to a sequence.

Alternative

Use SkipUntil to skip elements from an active subscription.

Warning

Although SubscribeWhen and SkipUntil often produce a similar sequence, SubscribeWhen only subscribes to the source sequence when triggered. This means that any initialization side-effects will be delayed. For hot sequences (e.g. camera) this might be disadvantageous as initialization costs are paid upon subscription, and new values after the trigger are not immediately available. However, for cold sequences (e.g. video or a timer) this might be beneficial, as all data from the start of the sequence will be available. For more about the difference between hot and cold sequences, see the section on temperature.

[Combinator]
public class SubscribeWhen

Inheritance

object

SubscribeWhen

Inherited Members

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

Methods

Process<TSource, TOther>(IObservable<TSource>, IObservable<TOther>)

Subscribes to an observable sequence only after the second sequence produces an element.