@webda/async • Readme | API

Class: AsyncJobService<T>

AsyncService allows you to launch jobs and report status

Webda Modda

Extends

Service<T>

Type parameters

• T extends AsyncJobServiceParameters = AsyncJobServiceParameters

Implements

RequestFilter

Constructors

new AsyncJobService(webda, name, params)

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

AsyncJobService<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

_webda

protected _webda: Core<CoreEvents>

Webda Core object

Inherited from

Service._webda

Source

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

binaryStore

protected binaryStore: CloudBinary<CloudBinaryParameters>

If we want job to be able to upload/download

Source

async/src/services/asyncjobservice.ts:185

logger

protected logger: Logger

Logger with class context

Inherited from

Service.logger

Source

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

metrics?

protected metrics?: any

Get metrics

Inherited from

Service.metrics

Source

core/lib/services/service.d.ts:159

model

model: Constructor<AsyncWebdaAction, [string, string, ...any[]]> & CoreModelDefinition<AsyncAction>

Model to use when launching action

Source

async/src/services/asyncjobservice.ts:189

operationModel

operationModel: Constructor<AsyncOperationAction, [string, OperationContext<any, any>, WorkerLogLevel?]>

Model to use when launching action

Source

async/src/services/asyncjobservice.ts:193

operations

protected operations: Object

Operations definition

Type declaration

application

application: Object

application.name

application.name: string

application.version

application.version: string

operations

operations: Object

Index signature

[key: string]: Object

schemas

schemas: Object

Index signature

[key: string]: JSONSchema7

Source

async/src/services/asyncjobservice.ts:197

operationsQueries

protected operationsQueries: Object = {}

Validator of sessions

Index signature

[key: string]: WebdaQL.QueryValidator

Source

async/src/services/asyncjobservice.ts:205

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

queue

protected queue: Queue<AsyncActionQueueItem, QueueParameters>

Queue for execution

Source

async/src/services/asyncjobservice.ts:168

runners

protected runners: Runner<RunnerParameters>[]

Runner to use

Source

async/src/services/asyncjobservice.ts:177

store

protected store: Store<AsyncAction, StoreParameters, StoreEvents>

Store for async actions

Source

async/src/services/asyncjobservice.ts:172

HMAC_ALGO

static HMAC_ALGO: string = "sha256"

HMAC Algorithm used for simple auth

Source

async/src/services/asyncjobservice.ts:181

captureRejectionSymbol

static readonly captureRejectionSymbol: typeof captureRejectionSymbol

Inherited from

Service.captureRejectionSymbol

Source

async/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

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

defaultMaxListeners

static defaultMaxListeners: number

Inherited from

Service.defaultMaxListeners

Source

async/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

async/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

async/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

callOperation()

callOperation(context): Promise<AsyncAction>

Call an operation for an external system

Parameters

• context: OperationContext<any, any>

Returns

Promise<AsyncAction>

Source

async/src/services/asyncjobservice.ts:466

checkRequest()

checkRequest(context): Promise<boolean>

Allow job status report url

Parameters

• context: WebContext<any, any>

Returns

Promise<boolean>

Implementation of

RequestFilter.checkRequest

Source

async/src/services/asyncjobservice.ts:300

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

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

executeAsAsyncAction()

executeAsAsyncAction(serviceName, method, ...args): Promise<void>

Execute a service.method as an AsyncAction

Useful for crontab execution

Parameters

• serviceName: string

• method: string

• ...args: any[]

Returns

Promise<void>

Source

async/src/services/asyncjobservice.ts:594

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

getCronExecutor()

getCronExecutor(cron): () => Promise<void>

Get the cron callback function

Parameters

• cron: CronDefinition

Returns

Function

Returns

Promise<void>

Source

async/src/services/asyncjobservice.ts:675

getHeaders()

getHeaders(jobInfo): Object

Return headers to request status hook

Parameters

• jobInfo: JobInfo

Returns

Object

Source

async/src/services/asyncjobservice.ts:544

getJobInfo()

getJobInfo(action): JobInfo

Get the job info

Parameters

• action: AsyncAction

Returns

JobInfo

Source

async/src/services/asyncjobservice.ts:393

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

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

getMetric()

getMetric<T>(type, configuration): T

Add service name label

Type parameters

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

handleEvent()

protected handleEvent(event): Promise<void>

Handle one event from the queue and launch the job

Parameters

• event: AsyncActionQueueItem

Returns

Promise<void>

Source

async/src/services/asyncjobservice.ts:356

init()

init(): Promise<AsyncJobService<T>>

Will be called after all the Services are created

Returns

Promise<AsyncJobService<T>>

Inherited from

Service.init

Abstract

Source

core/lib/services/service.d.ts:275

initMetrics()

initMetrics(): void

Init the metrics

Returns

void

Inherited from

Service.initMetrics

Source

core/lib/services/service.d.ts:201

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

launchAction()

launchAction(action): Promise<AsyncAction>

Launch the action asynchronously

Parameters

• action: AsyncAction

Returns

Promise<AsyncAction>

Source

async/src/services/asyncjobservice.ts:509

launchAsAsyncAction()

launchAsAsyncAction(serviceName, method, ...args): Promise<AsyncAction>

Launch a service.method as an AsyncAction

Parameters

• serviceName: string

• method: string

• ...args: any[]

Returns

Promise<AsyncAction>

Source

async/src/services/asyncjobservice.ts:582

launchOperation()

launchOperation(context): Promise<void>

Launch an operation through this service

Parameters

• context: WebContext<any, any>

Returns

Promise<void>

Source

async/src/services/asyncjobservice.ts:473

listOperations()

listOperations(context): Promise<void>

List available operations through this service

Parameters

• context: WebContext<void, string[] | Object>

Returns

Promise<void>

Source

async/src/services/asyncjobservice.ts:409

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

async/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

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

loadParameters()

loadParameters(params): ServiceParameters

Parameters

• params: any

Returns

ServiceParameters

Overrides

Service.loadParameters

Inherit Doc

Source

async/src/services/asyncjobservice.ts:210

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

async/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

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

postHook()

postHook(jobInfo, message): Promise<AsyncWebdaAction>

Post hook to a remote url or use local store to update status

Parameters

• jobInfo: JobInfo

• message: any

Returns

Promise<AsyncWebdaAction>

Source

async/src/services/asyncjobservice.ts:562

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

async/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

async/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

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

registerOperations()

registerOperations(operations): void

Parameters

• operations: Object

• operations.application: Object

• operations.application.name: string

• operations.application.version: string

• operations.operations: Object

• operations.schemas: Object

Returns

void

Source

async/src/services/asyncjobservice.ts:273

reinit()

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

Parameters

• config: DeepPartial<T>

new parameters for the service

Returns

Promise<AsyncJobService<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

async/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

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

resolve()

resolve(): this

Returns

this

Overrides

Service.resolve

Inherit Doc

Source

async/src/services/asyncjobservice.ts:216

runAsyncOperationAction()

runAsyncOperationAction(jobInfo?): Promise<void>

Wrap async job and call the job status hook

Parameters

• jobInfo?: JobInfo

Returns

Promise<void>

Source

async/src/services/asyncjobservice.ts:607

scheduleAction()

scheduleAction(action, timestamp): Promise<AsyncAction>

Schedule action for later execution

Parameters

• action: AsyncAction

• timestamp: number

Returns

Promise<AsyncAction>

Source

async/src/services/asyncjobservice.ts:529

scheduler()

scheduler(): CancelableLoopPromise

Manage scheduled actions and crontab actions

Returns

CancelableLoopPromise

Source

async/src/services/asyncjobservice.ts:696

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

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

statusHook()

protected statusHook(context): Promise<void>

Status hook for job report

Only updates specific fields: status, errorMessage, statusDetails, results, logs (appending)

Parameters

• context: WebContext<any, any>

Returns

Promise<void>

Source

async/src/services/asyncjobservice.ts:315

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

worker()

worker(): CancelablePromise<void>

Worker

This will launch actions based on defined runners

Returns

CancelablePromise<void>

Source

async/src/services/asyncjobservice.ts:332

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

async/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

async/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

async/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

async/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

async/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

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

Class: AsyncJobService<T>

Webda Modda​

Extends​

Type parameters​

Implements​

Constructors​

new AsyncJobService(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​

_webda​

Inherited from​

Source​

binaryStore​

Source​

logger​

Inherited from​

Source​

metrics?​

Inherited from​

Source​

model​

Source​

operationModel​

Source​

operations​

Type declaration​

application​

application.name​

application.version​

operations​

Index signature​

schemas​

Index signature​

Source​

operationsQueries​

Index signature​

Source​

parameters​

Inherited from​

Source​

queue​

Source​

runners​

Source​

store​

Source​

HMAC_ALGO​

Source​

captureRejectionSymbol​

Inherited from​

Source​

captureRejections​

Inherited from​

Source​

defaultMaxListeners​

Inherited from​

Source​

errorMonitor​

Inherited from​

Source​

Methods​

__clean()​

Returns​

Inherited from​

Abstract​

Webda Modda

Extends

Type parameters

Implements

Constructors

new AsyncJobService(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

_webda

Inherited from

Source

binaryStore

Source

logger

Inherited from

Source

metrics?

Inherited from

Source

model

Source

operationModel

Source

operations

Type declaration

application

application.name

application.version

operations

Index signature

schemas

Index signature

Source

operationsQueries

Index signature

Source

parameters

Inherited from

Source

queue

Source

runners

Source

store

Source

HMAC_ALGO

Source

captureRejectionSymbol

Inherited from

Source

captureRejections

Inherited from

Source

defaultMaxListeners

Inherited from

Source

errorMonitor

Inherited from

Source

Methods

__clean()

Returns

Inherited from

Abstract

Source