@webda/runtime • Readme | API

Class: ClusterService<T>

Cluster service

It will listen to all events and forward them to the pubsub so all others instances can be notified It will emit the event locally received from the pubsub

It will also invalidates cache based on these events

Webda Modda

Extends

Service<T>

Type parameters

• T extends ClusterServiceParameters = ClusterServiceParameters

Constructors

new ClusterService(webda, name, params)

new ClusterService<T>(webda, name, params?): ClusterService<T>

Parameters

• webda: Core<CoreEvents>

The main instance of Webda

• name: string

The name of the service

• params?: DeepPartial<T>

The parameters block define in the configuration file

Returns

ClusterService<T>

Inherited from

Service<T>.constructor

Source

core/lib/services/service.d.ts:168

Properties

_createException

_createException: string

Inherited from

Service._createException

Source

core/lib/services/service.d.ts:149

_initException

_initException: any

Inherited from

Service._initException

Source

core/lib/services/service.d.ts:151

_initTime

_initTime: number

Inherited from

Service._initTime

Source

core/lib/services/service.d.ts:150

_name

protected _name: string

Service name

Inherited from

Service._name

Source

core/lib/services/service.d.ts:142

_ready

_ready: boolean = false

If service is ready

Sent the welcome message

Source

runtime/src/services/cluster.ts:142

_webda

protected _webda: Core<CoreEvents>

Webda Core object

Inherited from

Service._webda

Source

core/lib/services/service.d.ts:138

emitterId

emitterId: string

Emitter id

Source

runtime/src/services/cluster.ts:116

hasCodeSyncAlert

hasCodeSyncAlert: boolean = false

If code is out of sync and warning has been displayed

Source

runtime/src/services/cluster.ts:99

logger

protected logger: Logger

Logger with class context

Inherited from

Service.logger

Source

core/lib/services/service.d.ts:155

members

members: Object = {}

Cluster member

Index signature

[key: string]: Object

Source

runtime/src/services/cluster.ts:104

metrics

metrics: Object

Type declaration

members

members: Gauge<string>

Overrides

Service.metrics

Source

runtime/src/services/cluster.ts:134

models

models: Object

Models defined in the app

Index signature

[key: string]: CoreModelDefinition

Source

runtime/src/services/cluster.ts:121

nodeData

nodeData: any = {}

Node data to send to other nodes

Source

runtime/src/services/cluster.ts:146

parameters

protected parameters: T

Hold the parameters for your service

It will be bring from the webda.config.json

Inherited from

Service.parameters

Source

core/lib/services/service.d.ts:148

pubSub

pubSub: default<ClusterMessage, ServiceParameters>

Source

runtime/src/services/cluster.ts:94

services

services: Object

Services defined in the app

Index signature

[key: string]: Service

Source

runtime/src/services/cluster.ts:127

stores

stores: Object

Stores defined in the app

Index signature

[key: string]: Store

Source

runtime/src/services/cluster.ts:132

captureRejectionSymbol

static readonly captureRejectionSymbol: typeof captureRejectionSymbol

Inherited from

Service.captureRejectionSymbol

Source

runtime/node_modules/@types/node/events.d.ts:328

captureRejections

static captureRejections: boolean

Sets or gets the default captureRejection value for all emitters.

Inherited from

Service.captureRejections

Source

runtime/node_modules/@types/node/events.d.ts:333

defaultMaxListeners

static defaultMaxListeners: number

Inherited from

Service.defaultMaxListeners

Source

runtime/node_modules/@types/node/events.d.ts:334

errorMonitor

static readonly errorMonitor: typeof errorMonitor

This symbol shall be used to install a listener for only monitoring 'error' events. Listeners installed using this symbol are called before the regular 'error' listeners are called.

Installing a listener using this symbol does not change the behavior once an 'error' event is emitted, therefore the process will still crash if no regular 'error' listener is installed.

Inherited from

Service.errorMonitor

Source

runtime/node_modules/@types/node/events.d.ts:327

Methods

__clean()

__clean(): Promise<void>

Clean the service data, can only be used in test mode

Returns

Promise<void>

Inherited from

Service.__clean

Abstract

Source

core/lib/services/service.d.ts:319

addListener()

addListener(eventName, listener): this

Alias for emitter.on(eventName, listener).

Parameters

• eventName: string | symbol

• listener: (...args) => void

Returns

this

Inherited from

Service.addListener

Since

v0.1.26

Source

runtime/node_modules/@types/node/events.d.ts:354

addRoute()

protected addRoute(url, methods, executer, openapi?, override?): void

Add a route dynamicaly

Parameters

• url: string

of the route can contains dynamic part like {uuid}

• methods: HttpMethodType[]

• executer: Function

Method to execute for this route

• openapi?: OpenAPIWebdaDefinition

• override?: boolean

Returns

void

Inherited from

Service.addRoute

Source

core/lib/services/service.d.ts:242

authorizeClientEvent()

authorizeClientEvent(_event, _context): boolean

Authorize a public event subscription

Parameters

• _event: string

• _context: OperationContext<any, any>

Returns

boolean

Inherited from

Service.authorizeClientEvent

Source

core/lib/services/service.d.ts:220

computeParameters()

computeParameters(): void

Used to compute or derivate input parameter to attribute

Returns

void

Inherited from

Service.computeParameters

Source

core/lib/services/service.d.ts:176

emit()

emit<Key>(event, data): boolean

Override to allow capturing long listeners

Type parameters

• Key extends string | number

Parameters

• event: symbol | Key

• data: Events[Key]

Returns

boolean

Inherited from

Service.emit

Source

core/lib/services/service.d.ts:289

emitSync()

emitSync<Key>(event, data): Promise<any[]>

Emit the event with data and wait for Promise to finish if listener returned a Promise

Type parameters

• Key extends string | number

Parameters

• event: Key

• data: Events[Key]

Returns

Promise<any[]>

Inherited from

Service.emitSync

Source

core/lib/services/service.d.ts:284

eventNames()

eventNames(): (string | symbol)[]

Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or Symbols.

const EventEmitter = require('events');
const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});

const sym = Symbol('symbol');
myEE.on(sym, () => {});

console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]

Returns

(string | symbol)[]

Inherited from

Service.eventNames

Since

v6.0.0

Source

runtime/node_modules/@types/node/events.d.ts:669

getClientEvents()

getClientEvents(): string[]

Return the events that an external system can subscribe to

Returns

string[]

Inherited from

Service.getClientEvents

Source

core/lib/services/service.d.ts:214

getKeepAliveMessage()

getKeepAliveMessage(): Promise<Partial<ClusterMessage>>

Return the keep alive message to be sent

Useful to override to add some dynamic data If the data is static you can use setMemberInfo

Returns

Promise<Partial<ClusterMessage>>

Source

runtime/src/services/cluster.ts:253

getMaxListeners()

getMaxListeners(): number

Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to defaultMaxListeners.

Returns

number

Inherited from

Service.getMaxListeners

Since

v1.0.0

Source

runtime/node_modules/@types/node/events.d.ts:526

getMembers()

getMembers(): Object

Return cluster members

Returns

Object

Source

runtime/src/services/cluster.ts:152

getMetric()

getMetric<T>(type, configuration): T

Add service name label

Type parameters

• T = Gauge<string> | Counter<string> | Histogram<string>

Parameters

• type: Constructor<T, [MetricConfiguration<T>]>

• configuration: MetricConfiguration<T>

Returns

T

Inherited from

Service.getMetric

Source

core/lib/services/service.d.ts:208

getName()

getName(): string

Get service name

Returns

string

Inherited from

Service.getName

Source

core/lib/services/service.d.ts:313

getOpenApiReplacements()

getOpenApiReplacements(): any

Return variables for replacement in openapi

Returns

any

Inherited from

Service.getOpenApiReplacements

Source

core/lib/services/service.d.ts:247

getOperationId()

getOperationId(id): string

If undefined is returned it cancel the operation registration

Parameters

• id: string

Returns

string

Inherited from

Service.getOperationId

Source

core/lib/services/service.d.ts:234

getParameters()

getParameters(): T

Get the service parameters

Returns

T

Inherited from

Service.getParameters

Source

core/lib/services/service.d.ts:180

getService()

getService<K>(service): K

Return a webda service

Type parameters

• K extends Service<ServiceParameters, Events>

Parameters

• service: string

name to retrieve

Returns

K

Inherited from

Service.getService

Source

core/lib/services/service.d.ts:309

getUrl()

getUrl(url, _methods): string

Return the full path url based on parameters

Parameters

• url: string

relative url to service

• _methods: HttpMethodType[]

in case we need filtering (like Store)

Returns

string

absolute url or undefined if need to skip the Route

Inherited from

Service.getUrl

Source

core/lib/services/service.d.ts:228

getWebda()

getWebda(): Core<CoreEvents>

Return WebdaCore

Returns

Core<CoreEvents>

Inherited from

Service.getWebda

Source

core/lib/services/service.d.ts:184

handleMessage()

protected handleMessage(message): Promise<void>

Handle message received by the pub/sub

Parameters

• message: ClusterMessage

Returns

Promise<void>

Source

runtime/src/services/cluster.ts:354

init()

init(): Promise<ClusterService<T>>

Returns

Promise<ClusterService<T>>

Overrides

Service.init

Source

runtime/src/services/cluster.ts:178

initMetrics()

initMetrics(): void

Add a prometheus gauge for members in the cluster

Returns

void

Overrides

Service.initMetrics

Source

runtime/src/services/cluster.ts:168

initOperations()

initOperations(): void

Init the operations

Returns

void

Inherited from

Service.initOperations

Source

core/lib/services/service.d.ts:255

initRoutes()

initRoutes(): void

Init the routes

Returns

void

Inherited from

Service.initRoutes

Source

core/lib/services/service.d.ts:251

listenerCount()

listenerCount(eventName): number

Returns the number of listeners listening to the event named eventName.

Parameters

• eventName: string | symbol

The name of the event being listened for

Returns

number

Inherited from

Service.listenerCount

Since

v3.2.0

Source

runtime/node_modules/@types/node/events.d.ts:616

listeners()

listeners(eventName): Function[]

Returns a copy of the array of listeners for the event named eventName.

server.on('connection', (stream) => {
  console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]

Parameters

• eventName: string | symbol

Returns

Function[]

Inherited from

Service.listeners

Since

v0.1.26

Source

runtime/node_modules/@types/node/events.d.ts:539

loadParameters()

loadParameters(params): ServiceParameters

Parameters

• params: DeepPartial<T>

Returns

ServiceParameters

Overrides

Service.loadParameters

Source

runtime/src/services/cluster.ts:159

log()

log(level, ...args): void

Parameters

• level: WorkerLogLevel

to log

• ...args: any[]

Returns

void

Inherited from

Service.log

Source

core/lib/services/service.d.ts:329

off()

off(eventName, listener): this

Alias for emitter.removeListener().

Parameters

• eventName: string | symbol

• listener: (...args) => void

Returns

this

Inherited from

Service.off

Since

v10.0.0

Source

runtime/node_modules/@types/node/events.d.ts:499

on()

on<Key>(event, listener): this

Type the listener part

Type parameters

• Key extends string | number

Parameters

• event: symbol | Key

• listener: (evt) => void

Returns

this

Inherited from

Service.on

Source

core/lib/services/service.d.ts:297

onAsync()

onAsync<Key>(event, listener, queue?): void

Listen to an event as on(...) would do except that it will be asynchronous

Type parameters

• Key extends string | number

Parameters

• event: Key

• listener: (evt) => void

• queue?: string

Name of queue to use, can be undefined, queue name are used to define differents priorities

Returns

void

Inherited from

Service.onAsync

Source

core/lib/services/service.d.ts:304

once()

once(eventName, listener): this

Adds a one-timelistener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

server.once('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

By default, event listeners are invoked in the order they are added. Theemitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
//   b
//   a

Parameters

• eventName: string | symbol

The name of the event.

• listener: (...args) => void

The callback function

Returns

this

Inherited from

Service.once

Since

v0.3.0

Source

runtime/node_modules/@types/node/events.d.ts:414

prependListener()

prependListener(eventName, listener): this

Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventNameand listener will result in the listener being added, and called, multiple times.

server.prependListener('connection', (stream) => {
  console.log('someone connected!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

• eventName: string | symbol

The name of the event.

• listener: (...args) => void

The callback function

Returns

this

Inherited from

Service.prependListener

Since

v6.0.0

Source

runtime/node_modules/@types/node/events.d.ts:634

prependOnceListener()

prependOnceListener(eventName, listener): this

Adds a one-timelistener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

server.prependOnceListener('connection', (stream) => {
  console.log('Ah, we have our first user!');
});

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

• eventName: string | symbol

The name of the event.

• listener: (...args) => void

The callback function

Returns

this

Inherited from

Service.prependOnceListener

Since

v6.0.0

Source

runtime/node_modules/@types/node/events.d.ts:650

rawListeners()

rawListeners(eventName): Function[]

Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));

// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];

// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();

// Logs "log once" to the console and removes the listener
logFnWrapper();

emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');

// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');

Parameters

• eventName: string | symbol

Returns

Function[]

Inherited from

Service.rawListeners

Since

v9.4.0

Source

runtime/node_modules/@types/node/events.d.ts:569

ready()

ready(): boolean

If service is ready

Returns

boolean

Source

runtime/src/services/cluster.ts:306

readyEndpoint()

readyEndpoint(ctx): void

Parameters

• ctx: WebContext<any, any>

Returns

void

Source

runtime/src/services/cluster.ts:294

reinit()

reinit(config): Promise<ClusterService<T>>

Parameters

• config: DeepPartial<T>

new parameters for the service

Returns

Promise<ClusterService<T>>

Inherited from

Service.reinit

Source

core/lib/services/service.d.ts:280

removeAllListeners()

removeAllListeners(event?): this

Removes all listeners, or those of the specified eventName.

It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

• event?: string | symbol

Returns

this

Inherited from

Service.removeAllListeners

Since

v0.1.26

Source

runtime/node_modules/@types/node/events.d.ts:510

removeListener()

removeListener(eventName, listener): this

Removes the specified listener from the listener array for the event namedeventName.

const callback = (stream) => {
  console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);

removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that anyremoveListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them fromemit() in progress. Subsequent events behave as expected.

const myEmitter = new MyEmitter();

const callbackA = () => {
  console.log('A');
  myEmitter.removeListener('event', callbackB);
};

const callbackB = () => {
  console.log('B');
};

myEmitter.on('event', callbackA);

myEmitter.on('event', callbackB);

// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
//   A
//   B

// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
//   A

Because listeners are managed using an internal array, calling this will change the position indices of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping')listener is removed:

const ee = new EventEmitter();

function pong() {
  console.log('pong');
}

ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);

ee.emit('ping');
ee.emit('ping');

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

• eventName: string | symbol

• listener: (...args) => void

Returns

this

Inherited from

Service.removeListener

Since

v0.1.26

Source

runtime/node_modules/@types/node/events.d.ts:494

resolve()

resolve(): this

Returns

this

Overrides

Service.resolve

Source

runtime/src/services/cluster.ts:330

sendMessage()

sendMessage(message, force?): Promise<void>

Send message to the pub/sub

Parameters

• message: Partial<ClusterMessage>

• force?: boolean

Returns

Promise<void>

Source

runtime/src/services/cluster.ts:316

setMaxListeners()

setMaxListeners(n): this

By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set toInfinity (or 0) to indicate an unlimited number of listeners.

Returns a reference to the EventEmitter, so that calls can be chained.

Parameters

• n: number

Returns

this

Inherited from

Service.setMaxListeners

Since

v0.3.5

Source

runtime/node_modules/@types/node/events.d.ts:520

setMemberInfo()

setMemberInfo(data, erase?): void

Allow to set some data on the member

Parameters

• data: any= {}

• erase?: boolean

will remove any other data

Returns

void

Source

runtime/src/services/cluster.ts:242

stop()

stop(): Promise<void>

Shutdown the current service if action need to be taken

Returns

Promise<void>

Inherited from

Service.stop

Source

core/lib/services/service.d.ts:188

toJSON()

toJSON(): string

Prevent service to be serialized

Returns

string

Inherited from

Service.toJSON

Source

core/lib/services/service.d.ts:268

toPublicJSON()

toPublicJSON(object): string

Convert an object to JSON using the Webda json filter

Parameters

• object: unknown

The object to export

Returns

string

The export of the strip object ( removed all attribute with _ )

Inherited from

Service.toPublicJSON

Source

core/lib/services/service.d.ts:263

toString()

toString(): string

Return service representation

Returns

string

Inherited from

Service.toString

Source

core/lib/services/service.d.ts:192

updateCluster()

updateCluster(): Promise<void>

Send a keep alive on pub/sub and remove any member that we haven't seen in the last 64s -> missed 2 ttl

Returns

Promise<void>

Source

runtime/src/services/cluster.ts:266

getEventListeners()

static getEventListeners(emitter, name): Function[]

Returns a copy of the array of listeners for the event named eventName.

For EventEmitters this behaves exactly the same as calling .listeners on the emitter.

For EventTargets this is the only way to get the event listeners for the event target. This is useful for debugging and diagnostic purposes.

const { getEventListeners, EventEmitter } = require('events');

{
  const ee = new EventEmitter();
  const listener = () => console.log('Events are fun');
  ee.on('foo', listener);
  getEventListeners(ee, 'foo'); // [listener]
}
{
  const et = new EventTarget();
  const listener = () => console.log('Events are fun');
  et.addEventListener('foo', listener);
  getEventListeners(et, 'foo'); // [listener]
}

Parameters

• emitter: EventEmitter | _DOMEventTarget

• name: string | symbol

Returns

Function[]

Inherited from

Service.getEventListeners

Since

v15.2.0, v14.17.0

Source

runtime/node_modules/@types/node/events.d.ts:299

listenerCount()

static listenerCount(emitter, eventName): number

A class method that returns the number of listeners for the given eventNameregistered on the given emitter.

const { EventEmitter, listenerCount } = require('events');
const myEmitter = new EventEmitter();
myEmitter.on('event', () => {});
myEmitter.on('event', () => {});
console.log(listenerCount(myEmitter, 'event'));
// Prints: 2

Parameters

• emitter: EventEmitter

The emitter to query

• eventName: string | symbol

The event name

Returns

number

Inherited from

Service.listenerCount

Since

v0.9.12

Deprecated

Since v3.2.0 - Use listenerCount instead.

Source

runtime/node_modules/@types/node/events.d.ts:271

on()

static on(emitter, eventName, options?): AsyncIterableIterator<any>

const { on, EventEmitter } = require('events');

(async () => {
  const ee = new EventEmitter();

  // Emit later on
  process.nextTick(() => {
    ee.emit('foo', 'bar');
    ee.emit('foo', 42);
  });

  for await (const event of on(ee, 'foo')) {
    // The execution of this inner block is synchronous and it
    // processes one event at a time (even with await). Do not use
    // if concurrent execution is required.
    console.log(event); // prints ['bar'] [42]
  }
  // Unreachable here
})();

Returns an AsyncIterator that iterates eventName events. It will throw if the EventEmitter emits 'error'. It removes all listeners when exiting the loop. The value returned by each iteration is an array composed of the emitted event arguments.

An AbortSignal can be used to cancel waiting on events:

const { on, EventEmitter } = require('events');
const ac = new AbortController();

(async () => {
  const ee = new EventEmitter();

  // Emit later on
  process.nextTick(() => {
    ee.emit('foo', 'bar');
    ee.emit('foo', 42);
  });

  for await (const event of on(ee, 'foo', { signal: ac.signal })) {
    // The execution of this inner block is synchronous and it
    // processes one event at a time (even with await). Do not use
    // if concurrent execution is required.
    console.log(event); // prints ['bar'] [42]
  }
  // Unreachable here
})();

process.nextTick(() => ac.abort());

Parameters

• emitter: EventEmitter

• eventName: string

The name of the event being listened for

• options?: StaticEventEmitterOptions

Returns

AsyncIterableIterator<any>

that iterates eventName events emitted by the emitter

Inherited from

Service.on

Since

v13.6.0, v12.16.0

Source

runtime/node_modules/@types/node/events.d.ts:254

once()

once(emitter, eventName, options)

static once(emitter, eventName, options?): Promise<any[]>

Creates a Promise that is fulfilled when the EventEmitter emits the given event or that is rejected if the EventEmitter emits 'error' while waiting. The Promise will resolve with an array of all the arguments emitted to the given event.

This method is intentionally generic and works with the web platform EventTarget interface, which has no special'error' event semantics and does not listen to the 'error' event.

const { once, EventEmitter } = require('events');

async function run() {
  const ee = new EventEmitter();

  process.nextTick(() => {
    ee.emit('myevent', 42);
  });

  const [value] = await once(ee, 'myevent');
  console.log(value);

  const err = new Error('kaboom');
  process.nextTick(() => {
    ee.emit('error', err);
  });

  try {
    await once(ee, 'myevent');
  } catch (err) {
    console.log('error happened', err);
  }
}

run();

The special handling of the 'error' event is only used when events.once()is used to wait for another event. If events.once() is used to wait for the 'error' event itself, then it is treated as any other kind of event without special handling:

const { EventEmitter, once } = require('events');

const ee = new EventEmitter();

once(ee, 'error')
  .then(([err]) => console.log('ok', err.message))
  .catch((err) => console.log('error', err.message));

ee.emit('error', new Error('boom'));

// Prints: ok boom

An AbortSignal can be used to cancel waiting for the event:

const { EventEmitter, once } = require('events');

const ee = new EventEmitter();
const ac = new AbortController();

async function foo(emitter, event, signal) {
  try {
    await once(emitter, event, { signal });
    console.log('event emitted!');
  } catch (error) {
    if (error.name === 'AbortError') {
      console.error('Waiting for the event was canceled!');
    } else {
      console.error('There was an error', error.message);
    }
  }
}

foo(ee, 'foo', ac.signal);
ac.abort(); // Abort waiting for the event
ee.emit('foo'); // Prints: Waiting for the event was canceled!

Parameters

• emitter: _NodeEventTarget

• eventName: string | symbol

• options?: StaticEventEmitterOptions

Returns

Promise<any[]>

Inherited from

Service.once

Since

v11.13.0, v10.16.0

Source

runtime/node_modules/@types/node/events.d.ts:194

once(emitter, eventName, options)

static once(emitter, eventName, options?): Promise<any[]>

Parameters

• emitter: _DOMEventTarget

• eventName: string

• options?: StaticEventEmitterOptions

Returns

Promise<any[]>

Inherited from

Service.once

Source

runtime/node_modules/@types/node/events.d.ts:195

setMaxListeners()

static setMaxListeners(n?, ...eventTargets?): void

const {
  setMaxListeners,
  EventEmitter
} = require('events');

const target = new EventTarget();
const emitter = new EventEmitter();

setMaxListeners(5, target, emitter);

Parameters

• n?: number

A non-negative number. The maximum number of listeners per EventTarget event.

• ...eventTargets?: (EventEmitter | _DOMEventTarget)[]

Returns

void

Inherited from

Service.setMaxListeners

Since

v15.4.0

Source

runtime/node_modules/@types/node/events.d.ts:317

Class: ClusterService<T>

Webda Modda​

Extends​

Type parameters​

Constructors​

new ClusterService(webda, name, params)​

Parameters​

Returns​

Inherited from​

Source​

Properties​

_createException​

Inherited from​

Source​

_initException​

Inherited from​

Source​

_initTime​

Inherited from​

Source​

_name​

Inherited from​

Source​

_ready​

Source​

_webda​

Inherited from​

Source​

emitterId​

Source​

hasCodeSyncAlert​

Source​

logger​

Inherited from​

Source​

members​

Index signature​

Source​

metrics​

Type declaration​

members​

Overrides​

Source​

models​

Index signature​

Source​

nodeData​

Source​

parameters​

Inherited from​

Source​

pubSub​

Source​

services​

Index signature​

Source​

stores​

Index signature​

Source​

captureRejectionSymbol​

Inherited from​

Source​

captureRejections​

Inherited from​

Source​

defaultMaxListeners​

Inherited from​

Source​

errorMonitor​

Inherited from​

Source​

Methods​

__clean()​

Returns​

Inherited from​

Abstract​

Source​

addListener()​

Parameters​

Returns​

Webda Modda

Extends

Type parameters

Constructors

new ClusterService(webda, name, params)

Parameters

Returns

Inherited from

Source

Properties

_createException

Inherited from

Source

_initException

Inherited from

Source

_initTime

Inherited from

Source

_name

Inherited from

Source

_ready

Source

_webda

Inherited from

Source

emitterId

Source

hasCodeSyncAlert

Source

logger

Inherited from

Source

members

Index signature

Source

metrics

Type declaration

members

Overrides

Source

models

Index signature

Source

nodeData

Source

parameters

Inherited from

Source

pubSub

Source

services

Index signature

Source

stores

Index signature

Source

captureRejectionSymbol

Inherited from

Source

captureRejections

Inherited from

Source

defaultMaxListeners

Inherited from

Source

errorMonitor

Inherited from

Source

Methods

__clean()

Returns

Inherited from

Abstract

Source

addListener()

Parameters

Returns

Inherited from