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API Documentation

This is a JavaScript classes documentation which describes both client and server instance creation and management.

Table of Contents

Migrating to 3.x/4.x

Departing from version 2.x, there's been some minor API changes. A breaking change is a server.eventList method, which is not a getter method anymore, because of the inclusion of a namespaces system throughout the library. Other methods will work seamlessly.

Migrating to 7.x

client.login now throws an error in case of failed login. Enclose the code using that method in a try/catch block to mitigate unhandled exceptions.

Client

var WebSocket = require('rpc-websockets').Client
var ws = new WebSocket('ws://localhost:8080')

new WebSocket(address[, options]) -> Client

Instantiate a WebSocket client.

Parameters:

  • address {String}: The URL of the WebSocket server. The URL path portion resolves to a server namespace. If the URL query key socket_id exists, it will be used as a socket identifier. Defaults to 'ws://localhost:8080'.
  • options {Object}: Client options that are also forwarded to ws.
    • autoconnect {Boolean}: Client autoconnect upon Client class instantiation. Defaults to true.
    • reconnect {Boolean}: Whether client should reconnect automatically once the connection is down. Defaults to true.
    • reconnect_interval {Number}: Time between adjacent reconnects. Defaults to 1000.
    • max_reconnects {Number}: Maximum number of times the client should try to reconnect. Defaults to 5. 0 means unlimited.
    • Any other option allowed in Node WebSocket
  • generate_request_id {Function} Custom function to generate request id instead of simple increment by default. Passes method and params to parameters.
  • dataPack {DataPack} data pack contains encoder and decoder.

ws.connect()

Connects to a previously defined server if not connected already. Should only be used in case autoconnect was disabled.

ws.call(method[, params[, timeout[, ws_options]]]) -> Promise

Calls a registered RPC method on server. Resolves once the response is ready. Throws if an RPC error was received. Throws if method resolves to undefined (JSON knows no undefined type, so the response will neither have result nor error properties which violates JSON-RPC 2.0).

Parameters:

  • method {String}: An RPC method name to run on server-side.
  • params {Object|Array}: Optional parameter(s) to be sent along the request.
  • timeout {Number}: Optional RPC reply timeout in milliseconds.
  • ws_options {Object}: Optional parameters passed to ws. Not available on web browsers.
    • compress {Boolean}: Specifies whether data should be compressed or not. Defaults to true when permessage-deflate is enabled.
    • binary {Boolean}: Specifies whether data should be sent as a binary or not. Default is autodetected.
    • mask {Boolean} Specifies whether data should be masked or not. Defaults to true when websocket is not a server client.
    • fin {Boolean} Specifies whether data is the last fragment of a message or not. Defaults to true.

ws.login(params) -> Promise

Logins with the other side of the connection.

Parameters are used for authentication with another side of the connection and are user-defined. Throws with a detailed message if the login fails.

ws.listMethods() -> Promise

Fetches a list of client's methods registered on server.

ws.notify(method[, params])

Sends a JSON-RPC 2.0 notification to server.

Parameters:

  • method {String}: An RPC method name to run on server-side.
  • params {Object|Array}: Optional parameter(s) to be sent along the request.

ws.subscribe(event) -> Promise

Subscribes for a defined event. If single event is provided, it throws in case of errors. If multiple events are provided, it returns status data from the server.

Parameters:

  • event {String|Array}: Event name.

ws.unsubscribe(event) -> Promise

Unsubscribes from a defined event. If single event is provided, it throws in case of errors. If multiple events are provided, it returns status data from the server.

Parameters:

  • event {String|Array}: Event name.

ws.close([code[, data]])

Closes a WebSocket connection gracefully.

Parameters:

  • code {Number}: Socket close code.
  • data {String}: Optional data to be sent to socket before closing.

Event: 'open'

Emits when the connection is opened and ready for use.

Event: 'error'

  • <Error>

Emits when a socket error is raised.

Event: 'close'

Emits when the connection is closed.

Event: <Notification>

  • <Object>

Emits a notification event with possible parameters a client has subscribed to once the server sends it.

Example:

ws.subscribe('feedUpdated')

ws.on('feedUpdated', handlerFunction)

Server

var WebSocketServer = require('rpc-websockets').Server

var server = new WebSocketServer({
  port: 8080,
  host: 'localhost'
})

new WebSocketServer([options]) -> Server

Instantiate a WebSocket server.

Parameters:

  • options {Object}: Server options that are also forwarded to ws.
    • port {Number}: Port number on which the server will listen for incoming requests.
    • host {String}: Address on which the server will listen for incoming requests.
  • dataPack {DataPack} data pack contains encoder and decoder.

Once the Server class is instantiated, you can use a ws library's instance via server.wss object.

server.register(method, handler[, namespace]) -> RPCMethod

Registers an RPC method and returns the RPCMethod object to manage method permissions.

Parameters:

  • method {String}: RPC method name.
  • handler {Function}: RPC function that will be fired with a signature of ([params[, socket_id]]) once the method is called. Should not return undefined (see ws.call).
  • namespace {String}: Namespace identifier. Defaults to /.

server.setAuth(handler[, namespace])

Sets a user-defined auth method. The handler function must return boolean true on auth success and boolean false on auth failure.

Parameters:

  • handler {Function}: An auth function that will be used when the client calls the login method. Must return boolean true on auth success and boolean false on auth failure.
  • namespace {String}: Namespace identifier. Defaults to /.

server.event(name[, namespace]) -> RPCMethod

Creates a new event that can be emitted to clients and returns the RPCMethod object to manage method permissions.

Parameters:

  • name {String}: Name of the event.
  • namespace {String}: Namespace identifier. Defaults to /.

server.emit(name[, ...params])

Emits a created event to clients.

Parameters:

  • name {String}: Name of the event.
  • ...params: Parameters forwarded to clients. If an object ({ }) is provided, parameters delivered to a client will appear in a by-name fashion.

server.eventList([namespace]) -> Array

Lists all created events.

Parameters:

  • namespace: Namespace identifier. Defaults to /.

server.of(name) -> Namespace

Returns a Namespace object initialized by the provided pathname upon connecting (eg: /chat). Defaults to /.

Parameters:

  • name {String}: Namespace identifier.

More information on Namespaces below.

server.createError(code, message[, data]) -> Object

Creates a structured error that can be thrown in a .register callback.

Parameters:

  • code {Number}: Indicates the error type that occurred.
  • message {String}: Provides a short description of the error.
  • data {String|Object}: Details containing additional information about the error.

server.closeNamespace(ns) -> Promise

Closes the given namespace and terminates all its clients.

server.close() -> Promise

Closes the server and terminates all clients.

Event: 'listening'

Emits when the server has started listening for requests.

Event: 'connection'

  • socket <ws.WebSocket>
  • request <http.IncomingMessage>

Emits when the client has connected.

Event: 'disconnection'

  • socket <ws.WebSocket>

Emits when the client has disconnected.

Event: 'close'

Emits when the server has closed.

Event: 'socket-error'

  • socket <ws.WebSocket>
  • <Error>

Emits when a websocket error is raised.

Event: 'error'

  • <Error>

Emits when a server error is raised.

IMethod

An object which is returned by .register. Includes functions that can require client authentication.

IMethod.protected()

Marks an RPC method as protected. The method will only be reachable if the client has successfully authenticated with .login.

IMethod.public()

Marks an RPC method as public. All clients, both authenticated and anonymous will be able to use the method. This is set by default on .register.

IEvent

An object which is returned by .event. Includes functions that can require client authentication.

IEvent.protected()

Marks an event as protected. The method will only be reachable if the client has successfully authenticated with .login.

IEvent.public()

Marks an event as public. All clients, both authenticated and anonymous will be able to subscribe to the event. This is set by default on .event.

Namespaces

Namespace represents a pool of sockets connected under a given scope identified by a pathname (eg: /chat). Basically borrows ideas from socket.io.

namespace.register(method, handler) -> RPCMethod

A convenience method for server.register using this namespace.

namespace.event(name)

A convenience method for server.event using this namespace.

get namespace.name -> String

Returns a namespace identifier.

namespace.connected() -> Object

Returns a hash of websocket objects connected to this namespace, identified by id.

namespace.emit(name[, ...params])

Emits a created event to clients connected to this namespace.

Parameters:

  • name {String}: Name of the event.
  • ...params: Parameters forwarded to clients in this namespace.

namespace.eventList -> Array

A convenience method that lists all created events in this namespace.

namespace.clients() -> Array

Returns a list of client unique identifiers connected to this namespace.