NativeScript WebSockets

This is a cross platform WebSocket library for IOS and Android.

License

My code is (c)2015-2016, Master Technology. All my code is LICENSED under the MIT License. The Android Library is also MIT, the iOS libraries used Apache 2.0; which you may view them by reading the "LICENSE" file.

I also do contract work; so if you have a module you want built for NativeScript (or any other software projects) feel free to contact me nathan@master-technology.com.

Installation

First run tns --version

v1.4 or later

Run tns plugin add nativescript-websockets in your ROOT directory of your project.

Limitations

• The sending of Protocols support is not fully implemented on both platforms. Do not depend on this; it only partially works..

Usage

There is two possible interfaces for you to use; the Simple WebSocket interface that emulates the browser based WebSockets and a more advanced WebSocket interface where you have more control.

Browser based Interface

require('nativescript-websockets');

var mySocket = new WebSocket("ws://echo.websocket.org", [ /* "protocol","another protocol" */]);
mySocket.addEventListener('open', function (evt) { console.log("We are Open"); evt.target.send("Hello"); });
mySocket.addEventListener('message', function(evt) { console.log("We got a message: ", evt.data); evt.target.close(); });
mySocket.addEventListener('close', function(evt) { console.log("The Socket was Closed:", evt.code, evt.reason); });
mySocket.addEventListener('error', function(evt) { console.log("The socket had an error", evt.error); });

Advanced Interface

var WS = require('nativescript-websockets');

var mySocket = new WS("ws://echo.websocket.org",{protocols: [/* 'chat', 'video' */], timeout: 6000, allowCellular: true, headers: { 'Authorization': 'Basic ...' }});
mySocket.on('open', function(socket) { console.log("Hey I'm open"); socket.send("Hello"); });
mySocket.on('message', function(socket, message) { console.log("Got a message", message); });
mySocket.on('close', function(socket, code, reason) { console.log("Socket was closed because: ", reason, " code: ", code); });
mySocket.on('error', function(socket, error) { console.log("Socket had an error", error);});

Browser Based WebSockets

The browser based WebSockets are virtually identical to what you would get if you were using a Browser; they are automatically opened when you create it; all four events have "event" objects with different values. You are not allowed to re-open a closed socket and you have no control over any additional features.

Create and OPENS a new BROWSER based WebSocket

new WebSocket(url, [protocols]);

Parameters

• URL - (String) - Web Socket URL to open
• Protocols - OPTIONAL (Array of String) - valid list protocols. Please see limitations note.

Attaches an event to the WebSocket

.attachEventListener(EventName, function)

.on(EventName, function)

Parameters

• EventName - (String) can be "open", "close", "message" and "error"
• function - (Function) the function that will be called when the event occurs

Advanced WebSockets

The Advanced WebSockets allow you a lot more control over setting up and creating; in addition if they are closed; you can re-open it without having to reset your events.

Create a new Advanced WebSocket

var WS = require('nativescript-websockets'); var ws = new WS(url, options);

Parameters

• URL - Url to Open
• Options ** protocols - (Array of string) - Valid protocols. (See Limitation note) ** timeout - timeout (Defaults to 60,0000ms on IOS amd 10,000ms on Android, setting this to 0 disables timeouts) ** allowCellular (ios only, defaults to True) - can disable the WebSocket from going over the cellular network

Attaches an event to the WebSocket

.attachEventListener(EventName, function, passedThis)

.on(EventName, function, passedThis)

Parameters

• EventName - (String) can be "open", "close", "message" and "error"
• Function - (Function) the function that will be called when the event occurs
• passedThis - the "this" you want the Function to have

Opens the WebSocket

.open()

Notes: in the Advanced WebSocket you can re-open a closed WebSocket...

Common Functions between Advanced and Browser WebSockets

Closes the open Socket

.close(code, reason)

Parameters

• code - OPTIONAL (Number) - code
• reason - OPTIONAL (String) - reason

Sends a Text or Binary Message

.send(message)

Parameters

• message - String or Array/ArrayBuffer - Text string or Binary Message to send

Retrieves the current State

.readyState

Values:

• 0 - Connection
• 1 - Open
• 2 - Closing
• 3 - Closed

The URL you opened

.url

Returns the protocol negotiated

.protocol

Please see notes on limitations.

Returns true if on IOS

.ios

Return true if on Android

.android

Remove an Event Listener

.removeEventListener (EventName, function)

.off(EventName, function)

Parameters

• EventName - (String) - Name of Event (open, close, message, error)
• function - (optional Function) - If you don't pass any function to this; this will remove ALL event listeners for that event, otherwise it will just remove that one event listener.

Check to see if it is open

.isOpen()

Returns true if the connection is open

Check to see if it is closed

.isClosed()

Returns true if the connection is closed

Check to see if it is connecting

.isConnecting()

Returns true if the connection is connecting

Check to see if the connection is closing

.isClosing()

Returns true if it is in the process of closing...

Tutorials

Need a little bit more help getting up and running with NativeScript Websockets? Check out these tutorials for NativeScript on the subject.

• Communicate with Websockets in a NativeScript Angular Application