gtm video tracker

gtm_video_tracker.html

<script type="text/javascript">
// This code loads the IFrame Player API code asynchronously.
(function GtmVideoTracker(){
    var tag = document.createElement('script');
    var firstScriptTag = document.getElementsByTagName('script')[0];
    window.GTMplayers = window.GTMplayers || [];

    tag.src = "https://www.youtube.com/iframe_api";
    firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);

    // Optional: Enable JS API if it is not already on the URL
    for(var p = document.getElementsByTagName('iframe'), i = p.length, r = /youtube\.com\/embed/; i--;) {
        if (r.test(p[i].src)) {
            if (p[i].src.indexOf('enablejsapi') === -1) {
                p[i].src += (p[i].src.indexOf('?') === -1 ? '?' : '&') + 'enablejsapi=1';
            }
        }
    }

    window.onYouTubeIframeAPIReady = window.onYouTubeIframeAPIReady || function() {
        for(var p = document.getElementsByTagName('iframe'), i = p.length, r = /youtube\.com\/embed/; i--;) {
            if (r.test(p[i].src)) {
                window.GTMplayers.push(new YT.Player(p[i], {
                    events: {
                        'onReady': onPlayerReady,
                        'onStateChange': onPlayerStateChange
                    }
                }));
            }
        }
    };

    window.onPlayerReady = window.onYouTubeIframeAPIReady || function(){
        window.playerReady = true;
    };

    /**
     // The API calls this function when the player's state changes.
     window.onPlayerStateChange = window.onPlayerStateChange || function (event) {
// do stuff here
}
             */
})();

</script>
<script src="//dpp750yjcl65g.cloudfront.net/analyticsengine/dist/video/beta/youtube-raw.js"></script>
        <script>
        (function(w,n,a){w[n]=w[n]||function(){return(w[n][a]=w[n][a]||[]).push(arguments)}}(window, 'videoTracking', 'c'));

if (typeof window.videoTracking == 'function') {
window.videoTracking(function(tracking) {

    //tracking.progress(10, 'percent');
    tracking.datalayer('dataLayer');

    var z = setInterval(function() {
        if (window.GTMplayers) {

            if (window.playerReady) {
                clearInterval(z);
                for(i = 0, len = window.GTMplayers.length; i < len; i++) {
                    tracking.player(window.GTMplayers[i]);
                }
            }
        } else if (window.players) {
            if (jQuery('.video-disabled').length < 1) {
                clearInterval(z);
                for(var _player in window.players) {
                    var obj = window.players[_player];
                    tracking.player(obj);
                }
            }


        }

    }, 300);
});
</script>

Here's a brief refactoring showing how I'd write the second bit as a function that immediately executes:

(function videoTracking($, tracking){
    var z = null;
    tracking.datalayer('dataLayer');
    z = setInterval(function() {
        if (window.GTMplayers) {
            if (window.playerReady) {
                clearInterval(z);
                for(i = 0, len = window.GTMplayers.length; i < len; i++) {
                    tracking.player(window.GTMplayers[i]);
                }
            }
        } else if (window.players) {
            if ($('.video-disabled').length < 1) {
                clearInterval(z);
                for(var _player in window.players) {
                    var obj = window.players[_player];
                    tracking.player(obj);
                }
            }
        }
    }, 300);
})(jQuery, tracking);