/*
simple postmessage plugin

Useful when a reveal slideshow is inside an iframe.
It allows to call reveal methods from outside.

Example:
   var reveal =  window.frames[0];

   // Reveal.prev(); 
   reveal.postMessage(JSON.stringify({method: 'prev', args: []}), '*');
   // Reveal.next(); 
   reveal.postMessage(JSON.stringify({method: 'next', args: []}), '*');
   // Reveal.slide(2, 2); 
   reveal.postMessage(JSON.stringify({method: 'slide', args: [2,2]}), '*');

Add to the slideshow:

	dependencies: [
        ...
		{ src: 'plugin/postmessage/postmessage.js', async: true, condition: function() { return !!document.body.classList; } }
	]


*/

(function (){

window.addEventListener("message", function (event){
    var data = JSON.parse(event.data),
        method = data.method,
        args = data.args;
    if (Reveal[method]){
        Reveal[method].apply(Reveal, data.args);
    }
}, false);
}());