From 5b53d59cbaf2daa5720b29e2df04b4a92a28bdd3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20Ma=C5=82ecki?= <me@mmalecki.com>
Date: Wed, 16 Apr 2014 10:01:31 +0200
Subject: [PATCH] Add optional callback to `pollBalance`

---
 lib/trader.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/trader.js b/lib/trader.js
index 43db0309..d7698e93 100644
--- a/lib/trader.js
+++ b/lib/trader.js
@@ -155,7 +155,7 @@ Trader.prototype.stopPolling = function () {
   clearInterval(this.rateInterval);
 };
 
-Trader.prototype.pollBalance = function () {
+Trader.prototype.pollBalance = function (callback) {
   var self = this;
 
   self.logger.info('collecting balance');
@@ -170,9 +170,15 @@ Trader.prototype.pollBalance = function () {
       self.tradeExchange.balance(next);
     }
   }, function (err, balance) {
+    if (err) {
+      return callback && callback(err);
+    }
+
     balance.timestamp = Date.now();
     self.logger.info('Balance update:', balance);
     self.balance = balance;
+
+    callback && callback(null, balance);
   });
 };