Class: EventBus

Defined in: src/sdk/data/EventBus.ts:106

An event bus that can be used to publish data from backend components and devices to consumers.

Constructors

Constructor

new EventBus(useAlternativeEventSync?, shouldResync?): EventBus

Defined in: src/sdk/data/EventBus.ts:128

Creates an instance of an EventBus.

Parameters

Parameter	Type	Description
useAlternativeEventSync?	boolean	Whether to sync events to other event bus instances using the Coherent flow event API (true) instead of the generic data listener (false). Flow event sync sends events to event bus instances on other Coherent views that are considered gauges. The generic data listener sync sends events to event bus instances on all other Coherent views. Defaults to false.
shouldResync?	boolean	Whether the the newly created bus should ask for a resync of all previously cached events after it is created. Defaults to true.

Returns

EventBus

Constructor

new EventBus(syncHandlerFactory?, shouldResync?): EventBus

Defined in: src/sdk/data/EventBus.ts:137

Creates an instance of an EventBus.

Parameters

Parameter	Type	Description
syncHandlerFactory?	EventBusSyncHandlerFactory	A function that creates an object that handles syncing events published to the new bus to other event bus instances. If not defined, then a built-in sync handler that sends events to all other Coherent views will be created and used.
shouldResync?	boolean	Whether the the newly created bus should ask for a resync of all previously cached events after it is created. Defaults to true.

Returns

EventBus

Properties

onWildcardSubDestroyedFunc()

protected readonly onWildcardSubDestroyedFunc: (sub) => void

Defined in: src/sdk/data/EventBus.ts:117

Responds to when a wildcard subscription is destroyed.

Parameters

Parameter	Type	Description
sub	HandlerSubscription<WildcardHandler>	The destroyed subscription.

Returns

void

Methods

forEachSubscribedTopic()

forEachSubscribedTopic(fn): void

Defined in: src/sdk/data/EventBus.ts:369

Executes a function once for each topic with at least one subscriber.

Parameters

Parameter	Type	Description
fn	(topic, subscriberCount) => void	The function to execute.

Returns

void

---

getPublisher()

getPublisher<E>(): Publisher<E>

Defined in: src/sdk/data/EventBus.ts:344

Gets a typed publisher from the event bus..

Type Parameters

Type Parameter
E

Returns

Publisher<E>

The typed publisher.

---

getSubscriber()

getSubscriber<E>(): EventSubscriber<E>

Defined in: src/sdk/data/EventBus.ts:352

Gets a typed subscriber from the event bus.

Type Parameters

Type Parameter
E

Returns

EventSubscriber<E>

The typed subscriber.

---

getTopicSubscriberCount()

getTopicSubscriberCount(topic): number

Defined in: src/sdk/data/EventBus.ts:361

Get the number of subscribes for a given topic.

Parameters

Parameter	Type	Description
topic	string	The name of the topic.

Returns

number

The number of subscribers.

---

on()

on(topic, handler, paused): Subscription

Defined in: src/sdk/data/EventBus.ts:174

Subscribes to a topic on the bus.

Parameters

Parameter	Type	Default value	Description
topic	string	undefined	The topic to subscribe to.
handler	Handler<any>	undefined	The handler to be called when an event happens.
paused	boolean	false	Whether the new subscription should be initialized as paused. Defaults to false.

Returns

Subscription

The new subscription.

---

onAll()

onAll(handler): Subscription

Defined in: src/sdk/data/EventBus.ts:214

Subscribes to all topics.

Parameters

Parameter	Type	Description
handler	WildcardHandler	The handler to subscribe to all events.

Returns

Subscription

The new subscription.

---

pub()

pub(topic, data, sync, isCached): void

Defined in: src/sdk/data/EventBus.ts:228

Publishes an event to the topic on the bus.

Parameters

Parameter	Type	Default value	Description
topic	string	undefined	The topic to publish to.
data	any	undefined	The event data to publish.
sync	boolean	false	Whether or the event should be synced to other event bus instances. Defaults to false.
isCached	boolean	true	Whether the event data should be cached. Cached data that are published to a topic can be retrieved by subscribers after the data was initially published. Defaults to true.

Returns

void