POC node-steam joinChat with promise

friends.js

/* lib/handlers/friends.js */

var Steam = require('../steam_client');
var SteamID = require('../steamID');

// install q with "npm install q"
var Q = require('q');

var EMsg = Steam.EMsg;
var schema = Steam.Internal;

var protoMask = 0x80000000;


// Methods

/** snipped **/

prototype.joinChat = function(steamID) {
    var self = this;
    // get a new deferred
    var deferred = Q.defer();
    
    this._send(EMsg.ClientJoinChat, schema.MsgClientJoinChat.serialize({
        steamIdChat: toChatID(steamID)
    }));

    // custom timeout to fail the join after 10 seconds
    var timeout = setTimeout(function() {
        deferred.reject(new Error("Timed out"));
        self.removeListener('chat:join', resolver);
    },10000);

    // quick and dirty resolver that listens to a event and resolves accordingly
    var resolver = function(data) {
        // not the channel we are looking for
        if(data["steamIdClan"] != steamID) {
            return;
        }
        // response successfull, resolve
        if(data["enterResponse"] == Steam.EChatRoomEnterResponse.Success) {
            deferred.resolve(data);
        } else { // reject otherwise
            deferred.reject(new Error(data["enterResponse"]));
        }
        
        // remove listener and timeout
        self.removeListener('chat:join', resolver);
        clearTimeout(timeout);
    }

    // listen for chat join events
    this.on('chat:join', resolver);

    return deferred.promise;
};

/** snipped **/

// Handlers

var handlers = prototype._handlers;

/** snipped **/

handlers[EMsg.ClientChatEnter] = function(data) {
  var chatEnter = schema.MsgClientChatEnter.parse(data);
  
  // this is the only lined added:
  this.emit('chat:join', chatEnter);
  
  var baseSize = schema.MsgClientChatEnter.baseSize;
  
  var numObj = data.readUInt32LE(baseSize);  
  var chatName = data.readCString(baseSize + 4);
  data = data.slice(baseSize + 4 + Buffer.byteLength(chatName) + 1);
  
  var chatRoom = this.chatRooms[chatEnter.steamIdClan || chatEnter.steamIdChat] = {};
  while (numObj--) {
    var object = require('../VDF').parse(data).MessageObject;
    chatRoom[object.steamid] = {
      rank: object.Details,
      permissions: object.permissions
    };
  }
};

/** snipped **/

index.js

/** snipped **/

bot.on('loggedOn', function() {
    console.log('Bot: Logged in!');
    
    bot.setPersonaState(Steam.EPersonaState.Online);
    bot.setPersonaName('MyBotName');

    bot.on('chatInvite', function(chatID, chatName, inviterID) {
        
        // this is the magic of promises
        bot.joinChat(chatID).then(function(data) {
            console.log("successfully joined chatroom");
            bot.sendMessage(chatID, "Hello chatroom", Steam.EChatEntryType.ChatMsg);
            // this would list all chatrooms
            //console.log(bot.chatRooms)
        }, function(e) {
            console.log("error", e);
        });
    });
});

this could obviously be cleaned up, but as a concept it should demonstrate the point.

this could further be expanded by implementing it into the core of the message receiver of the gc and resolve promises according to the jobid in the protobufs