Videoplayer require js module to leverage Youtube api

Videoplayer require js module

/*
  Videoplayer

  Author:     Stephen Zsolnai (http://www.zolla.co.uk)
  Decription: Youtube api video module. 
              This module will wait for the global callback from Youtube API if it is requested.
              That is the trigger to set up the necessary video players.
              Events will be fired to send tracking data and the video data is pulled from embedded iframes like so:

              <iframe id="competitionVideo" 
              class="js-player" 
              data-id="9wsnelEA3ME" 
              data-title="The title of the video" 
              type="text/html" 
              width="640" 
              height="390" 
              data-trigger-link="watchVideo"
              src="http://www.youtube.com/embed/9wsnelEA3ME?enablejsapi=1"
              frameborder="0"></iframe>

--------------------------------------------------------------------------*/
  


define([
    'jquery',
    'modules/gatracking'
], function ($, tracking) {
  'use strict';
  var videoPlayers = [];
  


  //video player instance.
  var Player = function($target) {
    this.player = new YT.Player($target[0], {
      events: {
        'onReady': onPlayerReady.bind(this),
        'onStateChange': onPlayerStateChange.bind(this)
      }
    });
    this.title = $target.data('title');
    this.id = $target.data('id');
    this.$triggerLink = $('#' + $target.data('triggerLink'));

    //Play related youtube video on trigger click.
    if (this.$triggerLink.length) {
      this.$triggerLink.on('click', function(e) {
        e.preventDefault();
        this.player.playVideo();
      }.bind(this));
    }
  }

  var onPlayerReady = function() {
      //nothing needs doing here as yet...
    },
    onPlayerStateChange = function(event) {
      if (event.data === YT.PlayerState.PLAYING) {
        tracking.sendEvent('video', 'play', this.title + '(' + this.id + ')');
      }
      if (event.data === YT.PlayerState.PAUSED) {
        tracking.sendEvent('video', 'pause', this.title);
      }
    }
  ;


  //Global entry point for API
  window.onYouTubeIframeAPIReady = function() {
    var $player = $('.js-player');
    if ($player.length) {
      $player.each(function() {
        videoPlayers.push(new Player($(this)));
      });
    }
  }

  var VideoPlayer = {
    activate: function() {
      //Load in the youtube api if a player exists on the page.
      //Thje rest of the module is initialised on the Youtube api callback once it has loaded.
      var $player = $('.js-player');
      if ($player.length) {
        // 2. This code loads the IFrame Player API code asynchronously.
        var tag = document.createElement('script');
        tag.src = "https://www.youtube.com/iframe_api";
        var firstScriptTag = document.getElementsByTagName('script')[0];
        firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
      }
    }
  };
  return VideoPlayer;


});