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Broadcast<P>

Broadcast event class allows for emitting and listening for events

Type Parameters​

P​

P extends object = Payload<string, any>

Constructors​

Constructor​

new Broadcast<P>(config?): Broadcast<P>

Broadcast class constructor.

Parameters​

config?​

BroadcastConfig

Returns​

Broadcast<P>

Methods​

addListener()​

protected addListener(type, listener): void

Check for the existence of a event type and create it if missing.

Parameters​

type​

P["type"]

The event type.

listener​

Listener<P>

Returns​

void

deleteEvent()​

deleteEvent(type): void

Delete an event and unregister all callbacks associated with it.

Parameters​

type​

P["type"]

The event to delete.

Returns​

void

destroy()​

destroy(): void

Destroy the BroadcastChannel. After calling this, no further messages will be received.

Returns​

void

emit()​

Call Signature​

emit<T>(type, payload?, options?): void

Emit an event to all listening contexts.

Type Parameters​
T​

T extends string

The Payload type, inferred from the event.

Parameters​
type​

T

The event type.

payload?​

undefined

The event payload.

options?​

EmitOptions

Returns​

void

Example​
bus.emit(
  EVENTS.LAYER_CLICK,
  {
    worldSpace: pickInfo.coordinate,
    screenSpace: pickInfo.pixel,
    index: pickInfo.index,
    object: pickInfo.object,
  },
);

Call Signature​

emit<T>(type, payload, options?): void

Emit an event to all listening contexts.

Type Parameters​
T​

T extends string

The Payload type, inferred from the event.

Parameters​
type​

T

The event type.

payload​

ExtractEvent<P, T> extends object ? Data : undefined

The event payload.

options?​

EmitOptions

Returns​

void

Example​
bus.emit(
  EVENTS.LAYER_CLICK,
  {
    worldSpace: pickInfo.coordinate,
    screenSpace: pickInfo.pixel,
    index: pickInfo.index,
    object: pickInfo.object,
  },
);

handleListeners()​

protected handleListeners(data): void

Iterate through listeners for the given topic and invoke callbacks if criteria match.

Parameters​

data​

P

The event payload containing type, optional payload, and optional targetId.

Returns​

void

Remarks​

If targetId is provided, delivery is scoped to a specific browser context. We assume exactly one bus instance per context, so events are delivered only when target === this.uuid. If omitted, the event is treated as a broadcast within this context (audience filtering may occur elsewhere).

init()​

protected init(): void

Initialize the BroadcastChannel and set up event listeners.

Returns​

void

off()​

off<T>(type, callback): void

Unregister callback for the specified event type.

Type Parameters​

T​

T extends string

The Payload type, inferred from the event.

Parameters​

type​

T

The event type.

callback​

(data) => void

Returns​

void

on()​

on<T>(type, callback): () => void

Register a callback to be executed when a message of the specified event type is received.

Type Parameters​

T​

T extends string

The Payload type, inferred from the event.

Parameters​

type​

T

The event type.

callback​

(data) => void

The callback function.

Returns​

(): void

Returns​

void

Example​

bus.on(EVENTS.MAP_CLICK, (e) => {
  if (!e.payload.picked) {
    setSelected(null);
  }
});

once()​

once<T>(type, callback): () => void

Register a callback to be executed only once for a specified event type.

Type Parameters​

T​

T extends string

The Payload type, inferred from the event.

Parameters​

type​

T

The event type.

callback​

(data) => void

The callback function.

Returns​

(): void

Returns​

void

onError()​

protected onError(error): void

Handle errors from the BroadcastChannel.

Parameters​

error​

MessageEvent<Error>

Error event.

Returns​

void

onMessage()​

protected onMessage(event): void

Process incoming messages.

Parameters​

event​

MessageEvent<P>

Incoming message event.

Returns​

void

removeListener()​

protected removeListener(type, id): void

Removes a listener by id.

Parameters​

type​

P["type"]

id​

UniqueId

Returns​

void

setEventEmitOptions()​

setEventEmitOptions(type, options): void

Set emit options for event by type, options will apply to all emits of this event

Keep in mind that options are merged: global, event, local (lowest to highest precendence)

Parameters​

type​

P["type"]

event type

options​

emit options

null | EmitOptions

Returns​

void

setEventsEmitOptions()​

setEventsEmitOptions(events): void

Set a series of events emit options

Parameters​

events​

Map<P["type"], null | EmitOptions>

map of event type & options

Returns​

void

setGlobalEmitOptions()​

setGlobalEmitOptions(options): void

Set global emit options, the lowest precedence options, to be merged with event emit options and local options

Parameters​

options​

emit options

null | EmitOptions

Returns​

void

getInstance()​

static getInstance<T>(config?): Broadcast<T>

Get the singleton instance of Broadcaster.

Type Parameters​

T​

T extends object = { target?: UniqueId; type: string; } | { payload: any; target?: UniqueId; type: string; }

Parameters​

config?​

BroadcastConfig

Optional custom configuration.

Returns​

Broadcast<T>

Properties​

channel​

protected channel: null | BroadcastChannel = null

channelName​

protected channelName: string = DEFAULT_CONFIG.channelName

emitOptions​

protected emitOptions: Map<P["type"], EmitOptions>

id​

readonly id: UniqueId

listeners​

protected listeners: Partial<Record<P["type"], Listener<P>[]>> = {}