a sample implementation of socket.io in angular2 and typescript

NodoSocket.service.ts

/**!
 * nodocms backend application
 * Copyright(c) 2015 Johannes Pichler - webpixels
 * Created by johannespichler on 23.11.15.
 * LGPLv3.0 Licensed
 **/




/**
    we declare io here for typescript. io is a global window object


    you have to provide socket.io in your html markup for your application like:
    <script src="socket.io/socket.io.js"></script>
    or
    <script src="path/to/my/socket.io.js"></script>
 */
declare var io:any;

/**
 * the NodoSocket Object Class
 */
export class NodoSocket {

    static instance:NodoSocket = null;
    static isCreating:Boolean = false;
    socket:any;

    /**
     * constuctor with control handle, that you can not instantiate by new NodoSocket();
     * socket should act as a real singleton, not to have multiple socket connection instances
     * within the same application to the same resource
     */
    constructor() {

        if (!NodoSocket.isCreating) {
            throw new Error("This is a real singleton. Get an instance via var socket = NodoSocket.getInsance(); !");
        }

        console.info("creating socket object");

        this.socket = io;
        console.info("establishing connection to server...");
        this.socket.connect();
    }


    /**
     * receive data form Socket-Server
     * @param eventName
     * @param callback
     */
    public on(eventName, callback):void {

        this.socket.on(eventName, function () {
            var args = arguments;
            if (typeof callback == "function") {
                callback.apply(this.socket, args);
            }
        });
    }

    /**
     * submit data to socket-server
     * @param eventName
     * @param data
     * @param callback
     */
    public emit(eventName, data, callback):void {
        this.socket.emit(eventName, data, function () {
            var args = arguments;
            if (typeof callback == "function") {
                callback.apply(this.socket, args);

            }
        });
    }




    /**
     * get instance wrapper
     * @returns {NodoSocket}
     */
    static getInstance():NodoSocket {

        if (NodoSocket.instance === null) {
            NodoSocket.isCreating = true;
            NodoSocket.instance = new NodoSocket();
            NodoSocket.isCreating = false;
        }

        console.log("NodoSocket.instance",NodoSocket.instance);
        return NodoSocket.instance;

    }


}

/**
 usage:
 in an angular2 component controller, you may use it that way:


 var mySocket = NodoSocket.getInstance();


 !!!IMPORTANT: the arguments you will get back in your callback depends on your socket server implementation

 mySocket.emit("api:model", {
                requestID: "aSampleRequestID,
                model: "aSampleCollectionName,
                action: "update",
                id: "aSampleID",
                doc: {firstname:"john", lastname:"doe"}
            }, function (err, result, data) {

                if(err){
                    // handle error here

                    return;
                }

                if(data){
                    // handle your data here
                }



            });


 or for listening on events

 !!!IMPORTANT: the arguments you will get back in your callback depends on your socket server implementation

 mySocket.on("api:model:created", function (collectionName, id, editor, requestID){
        // handle your stuff here
    });

 */