From 53238c47ce85b2746d8d3375dc909aff892de3e7 Mon Sep 17 00:00:00 2001
From: Hakim El Hattab <hakim.elhattab@gmail.com>
Date: Tue, 22 Apr 2014 19:01:59 +0200
Subject: [PATCH] null and type check what comes through postmessage

---
 js/reveal.js | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/js/reveal.js b/js/reveal.js
index 42edf90..1238f9f 100644
--- a/js/reveal.js
+++ b/js/reveal.js
@@ -575,11 +575,16 @@ var Reveal = (function(){
 
 		if( config.postMessage ) {
 			window.addEventListener( 'message', function ( event ) {
-				var data = JSON.parse( event.data );
-				var method = Reveal[data.method];
+				var data = event.data;
 
-				if( typeof method === 'function' ) {
-					method.apply( Reveal, data.args );
+				// Make sure we're dealing with JSON
+				if( data.charAt( 0 ) === '{' && data.charAt( data.length - 1 ) === '}' ) {
+					data = JSON.parse( data );
+
+					// Check if the requested method can be found
+					if( data.method && typeof Reveal[data.method] === 'function' ) {
+						Reveal[data.method].apply( Reveal, data.args );
+					}
 				}
 			}, false );
 		}