web_wsClient Namespace Reference

wilton/web/wsClient
WebSocket client for web-browsers. More...

Functions
Undefined	close (Object socket)
	Close WebSocket connection.
Undefined	isOpen (Object socket)
	Check whether WebSocket connnection is open.
Undefined	open (String url, Object|Undefined options, Function|Undefined callback)
	Open WebSocket connection to server.
Undefined	send (Object socket, Object|Array|String message, Function|Undefined callback)
	Send message to WebSocket server.
Undefined	subscribe (Object socket, String topic, Function callback)
	Subscribe to broadcasts from WebSocket server.

Detailed Description

This module allows to use WebSockets in web-browsers using "request-response" and "pub-sub" modes.

Protocol:

• client request: { messageId: "uid", payload: msg }

• server response: { messageId: "uid", payload: msg }

• server broadcast: { broadcast: "topic", payload: msg }

Usage example:

// open connection
ws.open("ws://127.0.0.1:8080/views/wsView", function(err, socket) {
    if (err) { ... }

    // send
    ws.send(socket, {
        foo: 42
    }, function(err, resp) {
        if (err) { ... }
        console.log(resp);
    });

    // subscribe for broadcast
    ws.subscribe(socket, "myTopic", function(err, msg) {
        if (err) { ... }
        console.log(msg);
    });

    // close
    // ws.close(socket);
});

Function Documentation

Undefined web_wsClient::close

(

Object

socket

)

Closes WebSocket connection.

Parameters

socket

Object Socket previously opened with open()

Returns

Undefined

Undefined web_wsClient::isOpen

(

Object

socket

)

Checks whether WebSocket connection is not in 'CLOSED' or 'CLOSING' state.

Parameters

socket

Object Socket previously opened with open()

Returns

Undefined

Undefined web_wsClient::open	(	String	url,
		Object|Undefined	options,
		Function|Undefined	callback
	)

Opens WebSocket connection to server, calls callback on connection established or on timeout.

Parameters

url	String URL of the WebSocket server
options	Object|Undefined configuration object, see possible options below
callback	Function|Undefined callback to receive opened Socket or error

Returns

Undefined

Options

• idGenerator Function|Undefined function that generates unique ID's for WS messages, default value: UUID generator
• logger Function|Undefined function that is called with a wrapped WS message for each outgoing and incoming message, default value: console.log()
• onError Function|Undefined function that is called with error message or event object on communication error, default value: console.error()
• timeoutMillis Number|Undefined timeout in milliseconds awaiting for a server response to WS message, default value: 10000

Undefined web_wsClient::send	(	Object	socket,
		Object|Array|String	message,
		Function|Undefined	callback
	)

Sends message to WebSocket server, calls specified callback with a server response or on timeout

Parameters

socket	Object Socket previously opened with open()
message	Object|Array|String message payload that is passed to server
callback	Function|Undefined callback to receive response or error

Returns

Undefined

Undefined web_wsClient::subscribe	(	Object	socket,
		String	topic,
		Function	callback
	)

Subscribes to broadcasts from WebSocket server, callback is called for each message that is broadcasted for the specified topic.

Parameters

socket	Object Socket previously opened with open()
topic	String topic name to recive broadcast on
callback	Function callback to receive broadcasted message or error

Returns

Undefined