ModuleClient class

Reference

Package:: azure-iot-device

IoT Hub device client used to connect a device with an Azure IoT hub. Users of the SDK should call one of the factory methods, fromConnectionString or fromSharedAccessSignature to create an IoT Hub device client.

Extends: InternalClient

Methods

close()
close(Callback<Disconnected>)	Closes the transport connection and destroys the client resources. Note: After calling this method the ModuleClient object cannot be reused.
fromAuthenticationProvider(AuthenticationProvider, any)	Creates an IoT Hub module client from the given authentication method and using the given transport type.
fromConnectionString(string, any)	Creates an IoT Hub device client from the given connection string using the given transport type.
fromEnvironment(any)
fromEnvironment(any, Callback<ModuleClient>)	Creates an IoT Hub module client by using configuration information from the environment. If an environment variable called `EdgeHubConnectionString` or `IotHubConnectionString` exists, then that value is used and behavior is identical to calling `fromConnectionString` passing that in. If those environment variables do not exist then the following variables MUST be defined: `- IOTEDGE_WORKLOADURI URI for iotedged's workload API - IOTEDGE_DEVICEID Device identifier - IOTEDGE_MODULEID Module identifier - IOTEDGE_MODULEGENERATIONID Module generation identifier - IOTEDGE_IOTHUBHOSTNAME IoT Hub host name - IOTEDGE_AUTHSCHEME Authentication scheme to use; must be "sasToken"`
fromSharedAccessSignature(string, any)	Creates an IoT Hub module client from the given shared access signature using the given transport type.
invokeMethod(string, MethodParams)
invokeMethod(string, MethodParams, Callback<MethodResult>)	Invokes a method on a downstream device or on another module on the same IoTEdge device. Please note that this feature only works when the module is being run as part of an IoTEdge device.
invokeMethod(string, string, MethodParams)
invokeMethod(string, string, MethodParams, Callback<MethodResult>)
onMethod(string, DoubleValueCallback<DeviceMethodRequest, DeviceMethodResponse>)	Registers a callback for a method named `methodName`.
sendOutputEvent(string, Message)
sendOutputEvent(string, Message, Callback<MessageEnqueued>)	Sends an event to the given module output
sendOutputEventBatch(string, Message[])
sendOutputEventBatch(string, Message[], Callback<MessageEnqueued>)	Sends an array of events to the given module output
setOptions(DeviceClientOptions)
setOptions(DeviceClientOptions, Callback<TransportConfigured>)	Passes options to the `ModuleClient` object that can be used to configure the transport.

Inherited Methods

abandon(Message)
abandon(Message, Callback<MessageAbandoned>)
addListener(string \| symbol, (args: any[]) => void)	Alias for `emitter.on(eventName, listener)`.
complete(Message)
complete(Message, Callback<MessageCompleted>)
emit(string \| symbol, any[])	Synchronously calls each of the listeners registered for the event named`eventName`, in the order they were registered, passing the supplied arguments to each. Returns `true` if the event had listeners, `false` otherwise. const EventEmitter = require('events'); const myEmitter = new EventEmitter(); // First listener myEmitter.on('event', function firstListener() { console.log('Helloooo! first listener'); }); // Second listener myEmitter.on('event', function secondListener(arg1, arg2) { console.log(`event with parameters ${arg1}, ${arg2} in second listener`); }); // Third listener myEmitter.on('event', function thirdListener(...args) { const parameters = args.join(', '); console.log(`event with parameters ${parameters} in third listener`); }); console.log(myEmitter.listeners('event')); myEmitter.emit('event', 1, 2, 3, 4, 5); // Prints: // [ // [Function: firstListener], // [Function: secondListener], // [Function: thirdListener] // ] // Helloooo! first listener // event with parameters 1, 2 in second listener // event with parameters 1, 2, 3, 4, 5 in third listener
eventNames()	Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or `Symbol`s. `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) ]`
getMaxListeners()	Returns the current max listener value for the `EventEmitter` which is either set by `emitter.setMaxListeners(n)` or defaults to defaultMaxListeners.
getTwin()
getTwin(Callback<Twin>)
listenerCount(string \| symbol)	Returns the number of listeners listening to the event named `eventName`.
listeners(string \| symbol)	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] ]`
off(string \| symbol, (args: any[]) => void)	Alias for `emitter.removeListener()`.
on(string \| symbol, (args: any[]) => void)	Adds the `listener` function to the end 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 `eventName`and `listener` will result in the `listener` being added, and called, multiple times. `server.on('connection', (stream) => { console.log('someone connected!'); });` Returns a reference to the `EventEmitter`, so that calls can be chained. By default, event listeners are invoked in the order they are added. The`emitter.prependListener()` method can be used as an alternative to add the event listener to the beginning of the listeners array. `const myEE = new EventEmitter(); myEE.on('foo', () => console.log('a')); myEE.prependListener('foo', () => console.log('b')); myEE.emit('foo'); // Prints: // b // a`
once(string \| symbol, (args: any[]) => void)	Adds a one-time`listener` 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. The`emitter.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`
open()
open(Callback<Connected>)
prependListener(string \| symbol, (args: any[]) => void)	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 `eventName`and `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.
prependOnceListener(string \| symbol, (args: any[]) => void)	Adds a one-time`listener` 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.
rawListeners(string \| symbol)	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');
reject(Message)
reject(Message, Callback<MessageRejected>)
removeAllListeners(string \| symbol)	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.
removeListener(string \| symbol, (args: any[]) => void)	Removes the specified `listener` from the listener array for the event named`eventName`. `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 any`removeListener()` or `removeAllListeners()` calls after emitting and_before_ the last listener finishes execution will not remove them from`emit()` 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.
sendEvent(Message)
sendEvent(Message, Callback<MessageEnqueued>)
sendEventBatch(Message[])
sendEventBatch(Message[], Callback<MessageEnqueued>)
setMaxListeners(number)	By default `EventEmitter`s 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 to`Infinity` (or `0`) to indicate an unlimited number of listeners. Returns a reference to the `EventEmitter`, so that calls can be chained.
setRetryPolicy(RetryPolicy)	Sets the retry policy used by the client on all operations. The default is ExponentialBackoffWithJitter.
setTransportOptions(any)
setTransportOptions(any, Callback<TransportConfigured>)
updateSharedAccessSignature(string, Callback<SharedAccessSignatureUpdated>)

Method Details

close()

function close(): Promise<Disconnected>

Returns

Promise<Disconnected>

close(Callback<Disconnected>)

Closes the transport connection and destroys the client resources. Note: After calling this method the ModuleClient object cannot be reused.

function close(closeCallback: Callback<Disconnected>)

Parameters

closeCallback: Callback<Disconnected>

fromAuthenticationProvider(AuthenticationProvider, any)

Creates an IoT Hub module client from the given authentication method and using the given transport type.

static function fromAuthenticationProvider(authenticationProvider: AuthenticationProvider, transportCtor: any): ModuleClient

Parameters

authenticationProvider: AuthenticationProvider

Object used to obtain the authentication parameters for the IoT hub.

transportCtor: any

Transport protocol used to connect to IoT hub.

Returns

ModuleClient

fromConnectionString(string, any)

Creates an IoT Hub device client from the given connection string using the given transport type.

static function fromConnectionString(connStr: string, transportCtor: any): ModuleClient

Parameters

connStr: string

A connection string which encapsulates "device connect" permissions on an IoT hub.

transportCtor: any

A transport constructor.

Returns

ModuleClient

fromEnvironment(any)

static function fromEnvironment(transportCtor: any): Promise<ModuleClient>

Parameters

transportCtor: any

Returns

Promise<ModuleClient>

fromEnvironment(any, Callback<ModuleClient>)

Creates an IoT Hub module client by using configuration information from the environment. If an environment variable called EdgeHubConnectionString or IotHubConnectionString exists, then that value is used and behavior is identical to calling fromConnectionString passing that in. If those environment variables do not exist then the following variables MUST be defined:

- IOTEDGE_WORKLOADURI          URI for iotedged's workload API
- IOTEDGE_DEVICEID             Device identifier
- IOTEDGE_MODULEID             Module identifier
- IOTEDGE_MODULEGENERATIONID   Module generation identifier
- IOTEDGE_IOTHUBHOSTNAME       IoT Hub host name
- IOTEDGE_AUTHSCHEME           Authentication scheme to use; must be "sasToken"

static function fromEnvironment(transportCtor: any, callback: Callback<ModuleClient>)

Parameters

transportCtor: any

Transport protocol used to connect to IoT hub.

callback: Callback<ModuleClient>

fromSharedAccessSignature(string, any)

Creates an IoT Hub module client from the given shared access signature using the given transport type.

static function fromSharedAccessSignature(sharedAccessSignature: string, transportCtor: any): ModuleClient

Parameters

sharedAccessSignature: string

A shared access signature which encapsulates "device connect" permissions on an IoT hub.

transportCtor: any

Returns

ModuleClient

invokeMethod(string, MethodParams)

function invokeMethod(deviceId: string, methodParams: MethodParams): Promise<MethodResult>

Parameters

deviceId: string

methodParams: MethodParams

Returns

Promise<MethodResult>

invokeMethod(string, MethodParams, Callback<MethodResult>)

Invokes a method on a downstream device or on another module on the same IoTEdge device. Please note that this feature only works when the module is being run as part of an IoTEdge device.

function invokeMethod(deviceId: string, methodParams: MethodParams, callback: Callback<MethodResult>)

Parameters

deviceId: string

target device identifier

methodParams: MethodParams

parameters of the direct method call

callback: Callback<MethodResult>

invokeMethod(string, string, MethodParams)

function invokeMethod(deviceId: string, moduleId: string, methodParams: MethodParams): Promise<MethodResult>

Parameters

deviceId: string

moduleId: string

methodParams: MethodParams

Returns

Promise<MethodResult>

invokeMethod(string, string, MethodParams, Callback<MethodResult>)

function invokeMethod(deviceId: string, moduleId: string, methodParams: MethodParams, callback: Callback<MethodResult>)

Parameters

deviceId: string

moduleId: string

methodParams: MethodParams

callback: Callback<MethodResult>

onMethod(string, DoubleValueCallback<DeviceMethodRequest, DeviceMethodResponse>)

Registers a callback for a method named methodName.

function onMethod(methodName: string, callback: DoubleValueCallback<DeviceMethodRequest, DeviceMethodResponse>)

Parameters

methodName: string

Name of the method that will be handled by the callback

callback: DoubleValueCallback<DeviceMethodRequest, DeviceMethodResponse>

Function that shall be called whenever a method request for the method called methodName is received.

sendOutputEvent(string, Message)

function sendOutputEvent(outputName: string, message: Message): Promise<MessageEnqueued>

Parameters

outputName: string

message: Message

Returns

Promise<MessageEnqueued>

sendOutputEvent(string, Message, Callback<MessageEnqueued>)

Sends an event to the given module output

function sendOutputEvent(outputName: string, message: Message, callback: Callback<MessageEnqueued>)

Parameters

outputName: string

Name of the output to send the event to

message: Message

Message to send to the given output

callback: Callback<MessageEnqueued>

sendOutputEventBatch(string, Message[])

function sendOutputEventBatch(outputName: string, messages: Message[]): Promise<MessageEnqueued>

Parameters

outputName: string

messages: Message[]

Returns

Promise<MessageEnqueued>

sendOutputEventBatch(string, Message[], Callback<MessageEnqueued>)

Sends an array of events to the given module output

function sendOutputEventBatch(outputName: string, messages: Message[], callback: Callback<MessageEnqueued>)

Parameters

outputName: string

Name of the output to send the events to

messages: Message[]

callback: Callback<MessageEnqueued>

setOptions(DeviceClientOptions)

function setOptions(options: DeviceClientOptions): Promise<TransportConfigured>

Parameters

options: DeviceClientOptions

Returns

Promise<TransportConfigured>

setOptions(DeviceClientOptions, Callback<TransportConfigured>)

Passes options to the ModuleClient object that can be used to configure the transport.

function setOptions(options: DeviceClientOptions, done: Callback<TransportConfigured>)

Parameters

options: DeviceClientOptions

A DeviceClientOptions object.

done: Callback<TransportConfigured>

Inherited Method Details

abandon(Message)

function abandon(message: Message): Promise<MessageAbandoned>

Parameters

message: Message

Returns

Promise<MessageAbandoned>

abandon(Message, Callback<MessageAbandoned>)

function abandon(message: Message, abandonCallback: Callback<MessageAbandoned>)

Parameters

message: Message

abandonCallback: Callback<MessageAbandoned>

addListener(string | symbol, (args: any[]) => void)

Alias for emitter.on(eventName, listener).

function addListener(eventName: string | symbol, listener: (args: any[]) => void): this

Parameters

eventName: string | symbol

listener: (args: any[]) => void

Returns

this

complete(Message)

function complete(message: Message): Promise<MessageCompleted>

Parameters

message: Message

Returns

Promise<MessageCompleted>

complete(Message, Callback<MessageCompleted>)

function complete(message: Message, completeCallback: Callback<MessageCompleted>)

Parameters

message: Message

completeCallback: Callback<MessageCompleted>

emit(string | symbol, any[])

Synchronously calls each of the listeners registered for the event namedeventName, in the order they were registered, passing the supplied arguments to each. Returns true if the event had listeners, false otherwise.

const EventEmitter = require('events');
const myEmitter = new EventEmitter();

// First listener
myEmitter.on('event', function firstListener() {
  console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
  console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
  const parameters = args.join(', ');
  console.log(`event with parameters ${parameters} in third listener`);
});

console.log(myEmitter.listeners('event'));

myEmitter.emit('event', 1, 2, 3, 4, 5);

// Prints:
// [
//   [Function: firstListener],
//   [Function: secondListener],
//   [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener

function emit(eventName: string | symbol, args: any[]): boolean

Parameters

eventName: string | symbol

args: any[]

Returns

boolean

eventNames()

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) ]

function eventNames(): Array<string | symbol>

Returns

Array<string | symbol>

getMaxListeners()

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

function getMaxListeners(): number

Returns

number

getTwin()

function getTwin(): Promise<Twin>

Returns

Promise<Twin>

getTwin(Callback<Twin>)

function getTwin(done: Callback<Twin>)

Parameters

done: Callback<Twin>

listenerCount(string | symbol)

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

function listenerCount(eventName: string | symbol): number

Parameters

eventName: string | symbol

The name of the event being listened for

Returns

number

listeners(string | symbol)

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] ]

function listeners(eventName: string | symbol): Function[]

Parameters

eventName: string | symbol

Returns

Function[]

off(string | symbol, (args: any[]) => void)

Alias for emitter.removeListener().

function off(eventName: string | symbol, listener: (args: any[]) => void): this

Parameters

eventName: string | symbol

listener: (args: any[]) => void

Returns

this

on(string | symbol, (args: any[]) => void)

Adds the listener function to the end 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.on('connection', (stream) => {
  console.log('someone connected!');
});

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.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

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

function on(eventName: string | symbol, listener: (args: any[]) => void): this

Parameters

eventName: string | symbol

The name of the event.

listener: (args: any[]) => void

The callback function

Returns

this

once(string | symbol, (args: any[]) => void)

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

function once(eventName: string | symbol, listener: (args: any[]) => void): this

Parameters

eventName: string | symbol

The name of the event.

listener: (args: any[]) => void

The callback function

Returns

this

open()

function open(): Promise<Connected>

Returns

Promise<Connected>

open(Callback<Connected>)

function open(openCallback: Callback<Connected>)

Parameters

openCallback: Callback<Connected>

prependListener(string | symbol, (args: any[]) => void)

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.

function prependListener(eventName: string | symbol, listener: (args: any[]) => void): this

Parameters

eventName: string | symbol

The name of the event.

listener: (args: any[]) => void

The callback function

Returns

this

prependOnceListener(string | symbol, (args: any[]) => void)

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.

function prependOnceListener(eventName: string | symbol, listener: (args: any[]) => void): this

Parameters

eventName: string | symbol

The name of the event.

listener: (args: any[]) => void

The callback function

Returns

this

rawListeners(string | symbol)

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');

function rawListeners(eventName: string | symbol): Function[]

Parameters

eventName: string | symbol

Returns

Function[]

reject(Message)

function reject(message: Message): Promise<MessageRejected>

Parameters

message: Message

Returns

Promise<MessageRejected>

reject(Message, Callback<MessageRejected>)

function reject(message: Message, rejectCallback: Callback<MessageRejected>)

Parameters

message: Message

rejectCallback: Callback<MessageRejected>

removeAllListeners(string | symbol)

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.

function removeAllListeners(event?: string | symbol): this

Parameters

event: string | symbol

Returns

this

removeListener(string | symbol, (args: any[]) => void)

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.

function removeListener(eventName: string | symbol, listener: (args: any[]) => void): this

Parameters

eventName: string | symbol

listener: (args: any[]) => void

Returns

this

sendEvent(Message)

function sendEvent(message: Message): Promise<MessageEnqueued>

Parameters

message: Message

Returns

Promise<MessageEnqueued>

sendEvent(Message, Callback<MessageEnqueued>)

function sendEvent(message: Message, sendEventCallback: Callback<MessageEnqueued>)

Parameters

message: Message

sendEventCallback: Callback<MessageEnqueued>

sendEventBatch(Message[])

function sendEventBatch(messages: Message[]): Promise<MessageEnqueued>

Parameters

messages: Message[]

Returns

Promise<MessageEnqueued>

sendEventBatch(Message[], Callback<MessageEnqueued>)

function sendEventBatch(messages: Message[], sendEventBatchCallback: Callback<MessageEnqueued>)

Parameters

messages: Message[]

sendEventBatchCallback: Callback<MessageEnqueued>

setMaxListeners(number)

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.

function setMaxListeners(n: number): this

Parameters

n: number

Returns

this

setRetryPolicy(RetryPolicy)

Sets the retry policy used by the client on all operations. The default is ExponentialBackoffWithJitter.

function setRetryPolicy(policy: RetryPolicy)

Parameters

policy: RetryPolicy

The retry policy that should be used for all future operations.

setTransportOptions(any)

function setTransportOptions(options: any): Promise<TransportConfigured>

Parameters

options: any

Returns

Promise<TransportConfigured>

setTransportOptions(any, Callback<TransportConfigured>)

function setTransportOptions(options: any, done: Callback<TransportConfigured>)

Parameters

options: any

done: Callback<TransportConfigured>

updateSharedAccessSignature(string, Callback<SharedAccessSignatureUpdated>)

function updateSharedAccessSignature(sharedAccessSignature: string, updateSasCallback?: Callback<SharedAccessSignatureUpdated>)

Parameters

sharedAccessSignature: string

updateSasCallback: Callback<SharedAccessSignatureUpdated>

ModuleClient class

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Methods

Inherited Methods

Method Details

close()

Returns

close(Callback<Disconnected>)

Parameters

fromAuthenticationProvider(AuthenticationProvider, any)

Parameters

Returns

fromConnectionString(string, any)

Parameters

Returns

fromEnvironment(any)

Parameters

Returns

fromEnvironment(any, Callback<ModuleClient>)

Parameters

fromSharedAccessSignature(string, any)

Parameters

Returns

invokeMethod(string, MethodParams)

Parameters

Returns

invokeMethod(string, MethodParams, Callback<MethodResult>)

Parameters

invokeMethod(string, string, MethodParams)

Parameters

Returns

invokeMethod(string, string, MethodParams, Callback<MethodResult>)

Parameters

onMethod(string, DoubleValueCallback<DeviceMethodRequest, DeviceMethodResponse>)

Parameters

sendOutputEvent(string, Message)

Parameters

Returns

sendOutputEvent(string, Message, Callback<MessageEnqueued>)

Parameters

sendOutputEventBatch(string, Message[])

Parameters

Returns

sendOutputEventBatch(string, Message[], Callback<MessageEnqueued>)

Parameters

setOptions(DeviceClientOptions)

Parameters

Returns

setOptions(DeviceClientOptions, Callback<TransportConfigured>)

Parameters

Inherited Method Details

abandon(Message)

Parameters

Returns

abandon(Message, Callback<MessageAbandoned>)

Parameters

addListener(string | symbol, (args: any[]) => void)

Parameters

Returns

complete(Message)

Parameters

Returns

complete(Message, Callback<MessageCompleted>)

Parameters

emit(string | symbol, any[])

Parameters

Returns

eventNames()

Returns

getMaxListeners()

Returns

getTwin()

Returns

getTwin(Callback<Twin>)

Parameters

listenerCount(string | symbol)

Parameters

Returns

listeners(string | symbol)

Parameters