JavaScript: Calling variable functions of an initiated class (packet-handler)

Question

JavaScript: Calling variable functions of an initiated class (packet-handler)

I'm building a server/client model with Node.JS and want to call a function of an already instantiated class by using a variable packet-ID and handle the incoming server-packets by different functions. Therefore I put the packet-ids as properties of the PacketMethods object and the function to call as the value of each packet-id-property. However in this example when ServerList() is called, it's not a member of the initiated Client Class and therefore this.socket is undefined.

How could I call the packet-handling functions so that they're a member of the Client?

function Client (...)
{
  this.socket = new net.Socket();

  ...
}

Client.prototype.HandlePacket = function(blocks)
{
  try {
    var sPacket = new WRPacket(blocks);
    var PacketMethods = {
      4352 : this.ServerList
      4351 : this.LoginResponse
    }

    if(PacketMethods.hasOwnProperty(sPacket._packetid))
      PacketMethods[sPacket._packetid](sPacket);
    else
      console.log('Unhandled Packet: '+sPacket._packetid);
    } catch(err) {
      console.log("Error at Packet-Handler:\n"+err);
  }
}

Client.prototype.ServerList = function(Packet) 
{
  console.log('Serverlist received ...');
  ...
  this.socket.end();
}

Thank you!

javascript
node.js

Answer 1

You can bind the methods to your instance:

var PacketMethods = {
  4352 : this.ServerList.bind(this),
  4351 : this.LoginResponse.bind(this)
}

Answer 2

You could simply use the PacketMethods to store the names of your methods, then call them with the correct context:

var PacketMethods = {
    4352 : 'ServerList'
    4351 : 'LoginResponse'
};

if (PacketMethods.hasOwnProperty(sPacket._packetid)) {
    var method = PacketMethods[sPacket._packetid];
    this[method](sPacket);
}