title: How to check if YT.Player Object has been readied?
body: <p>There are multiple YT.player objects created on different  elements on the same page.</p>
  
  <pre><code> player1 = new YT.Player( 'player-1' , {...
   player2 = new YT.Player( 'player-2' , {...
   player3 = new YT.Player( 'player-3' , {...
  </code></pre>
  
  <p>Some divs visibility is changeable via Javascript. On some browsers (e.g. IE 11) the onPlayerReady callback of the Youtube Iframe API is only called once the DIV becomes visible.</p>
  
  <pre><code>  // 4. The API will call this function when the video player is ready.
    function onPlayerReady(event) {
      event.target.playVideo();
    }
  </code></pre>
  
  <p>Is there some build in check to see wether the YT.player object has been readied or not?</p>
  
  <p>In other words can I check player-1, player-2, player-3 before I call for example stopVideo on them? Because if I call</p>
  
  <pre><code>player-3.stopVideo()
  </code></pre>
  
  <p>and player-3 has not received an onPlayerReady event, I get an "unknown Method stopVideo()"-Exception.</p>