(JavaScript) WebSocket Connect

Demonstrates how to establish a WebSocket connection. Once the connection is established, messages may be sent back-and-forth. Messages are sent in frames, where the last frame in the message is indicated by a "final" bit. A frame constitutes the entire message if the first frame sent has the "final" bit sent. (In most cases, you'll probably be sending single-frame messages.)

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// --------------------------------------------------
// A WebSocket connection begins life as an HTTP GET request containing a few special header fields,
// such as "Upgrade: websocket".   

// Your application will use the Chilkat Rest class to send the initial HTTP GET.  This allows you
// to use the full capability of the Chilkat Rest class to customize the GET for any particular situation.
// For example:
// 
//   - If custom HTTP request header fields must be added.
//   - If authentication is required, such as OAuth2, OAuth1, Basic HTTP Auth, etc.
//   - If HTTPS, SSH Tunneling, Proxies (HTTP or SOCKS), or other advanced connection or TLS features are required.
// 

var rest = new CkRest();
success = rest.Connect("someserver.com",80,false,false);
if (success !== true) {
    console.log(rest.LastErrorText);
    return;
}

var ws = new CkWebSocket();

// Tell the WebSocket to use this connection.
success = ws.UseConnection(rest);
if (success !== true) {
    console.log(ws.LastErrorText);
    return;
}

// Add the standard WebSocket open handshake headers that will be needed.
// (This adds the required HTTP request headers to the rest object.)
ws.AddClientHeaders();

// Add any additional headers that might be desired.
// Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
rest.AddHeader("Sec-WebSocket-Protocol","x-something");
rest.AddHeader("Origin","http://someserver.com");

// Do the open handshake.
var responseBody = rest.FullRequestNoBody("GET","/something");
if (rest.LastMethodSuccess !== true) {
    console.log(rest.LastErrorText);
    return;
}

// If successful, the HTTP response status code should be 101,
// and the response body will be empty. (If it failed, we'll have a look
// at the response body..)
var statusCode = rest.ResponseStatusCode;
console.log("Response status code: " + statusCode);

if (statusCode !== 101) {
    console.log(responseBody);
    console.log("-- Failed because of unexpected response status code.");
    return;
}

// We have the expected 101 response, so let's now validate the 
// contents of the response, such as the value sent by the server in the
// Sec-WebSocket-Accept header. 
success = ws.ValidateServerHandshake();
if (success !== true) {
    console.log(ws.LastErrorText);
    return;
}

console.log("WebSocket connection successful.");

// The application may now begin sending and receiving frames on the WebSocket connection.
// (At this point, we're done with the rest object...)