XWiki WebSocket

Allows you to create WebSocket enabled Applications in XWiki.

How it works

You create a component in XWiki which implements WebSocketHandler and you use @Named to specify a name for it, then when a client connects to the XWiki WebSocket passing the name of your component as the path, your component will be called.

Example

A simple example is the EchoWebSocketHandler which simply replies to each WebSocket message with the same message. Because the EchoWebSocketHandler is named echo, WebSockets directed to the /echo path will reach this handler.

@Component
@Named("echo")
public class EchoWebSocketHandler implements WebSocketHandler
{
    public void onWebSocketConnect(WebSocket sock)
    {
        sock.onMessage(new WebSocket.Callback() {
            public void call(WebSocket sock)
            {
                String msg = sock.recv();
                sock.send(msg);
            }
        });
    }
}

Accessing the handler

To get a WebSocket URL for accessing the echo server, simply use the provided ScriptService in Velocity as follows:

{{velocity}}
{{html clean=false}}
<script>
    // this is a valid WebSocket URL
    var WEBSOCKET_URL = "$services.websocket.getURL('echo')";
</script>
{{/html}}
{{/velocity}}

Then to open a socket to this URL, use the WebSocket API in the browser as normal.

var ws = new WebSocket(WEBSOCKET_URL);
ws.onopen = function () {
    console.log("Websocket Opened");
    ws.send("Hello World!");
};
ws.onmessage = function (msg) {
    console.log(msg.data);
    if (msg.data === 'Hello World!') {
        console.log("Yay it worked!");
    }
};

Read the code of the EchoWebSocketHandler for yourself.

Bugs

• onDisconnect messages are not emitted when a client disconnects. This is because Nettosphere does not emit them and I was unable to reflect the underlying socket. (fixed in 1.6)

Releasing with Maven

May the force be with you and good luck.

mvn org.apache.maven.plugins:maven-release-plugin:2.5:prepare -Pintegration-tests -Darguments="-DskipTests -Dxwiki.enforcer.skip=true" -DskipTests
mvn org.apache.maven.plugins:maven-release-plugin:2.5:perform -Pintegration-tests -Darguments="-DskipTests -Dxwiki.enforcer.skip=true" -DskipTests