add optionnal callback

Author: jrainville

js/embark.js

@@ -263,11 +263,11 @@ EmbarkJS.Messages.sendMessage = function(options) {
   return this.currentMessages.sendMessage(options);
 };
 
-EmbarkJS.Messages.listenTo = function(options) {
+EmbarkJS.Messages.listenTo = function(options, callback) {
   if (!this.currentMessages) {
     throw new Error('Messages provider not set; e.g EmbarkJS.Messages.setProvider("whisper")');
   }
-  return this.currentMessages.listenTo(options);
+  return this.currentMessages.listenTo(options, callback);
 };
 
 EmbarkJS.Utils = {

lib/modules/whisper/js/embarkjs.js

@@ -64,7 +64,7 @@ __embarkWhisperNewWeb3.sendMessage = function (options) {
   });
 };
 
-__embarkWhisperNewWeb3.listenTo = function (options) {
+__embarkWhisperNewWeb3.listenTo = function (options, callback) {
   var topics = options.topic || options.topics;
 
   let promise = new __MessageEvents();
@@ -82,12 +82,15 @@ __embarkWhisperNewWeb3.listenTo = function (options) {
     var payload = JSON.parse(EmbarkJS.Utils.toAscii(result.payload));
     var data;
     data = {
-      topic: result.topic,
+      topic: EmbarkJS.Utils.toAscii(result.topic),
       data: payload,
       //from: result.from,
       time: result.timestamp
     };
 
+    if (callback) {
+      return callback(null, data);
+    }
     promise.cb(payload, data, result);
   });