index.html

<!DOCTYPE html>
<html style="background-color:#DDD; margin: 1em auto 1em; font-size: 26px; line-height: 39px; max-width: 1260px;">
  <head>
    <base target="_top">
    <title>YouTube Playlist for Subscriptions</title>
  </head>
  <body>
<script>
function copy_function(event) {
  var copyTextarea = document.querySelector('.js-copytextarea');
  copyTextarea.select();

  try {
    var successful = document.execCommand('copy');
    var msg = successful ? 'successful' : 'unsuccessful';
    console.log('Copying text command was ' + msg);
  } catch (err) {
    console.log('Oops, unable to copy');
  }
};
</script>

  <textarea style="width: 1px; height: 1px; padding: 0px; border: 0px;"
            class="js-copytextarea">javascript:(function() { if (confirm('Remove all watched videos?')) {var i = window.setInterval(function() {var closeButton = document.querySelector('.watched-badge'); if (closeButton) { closeButton.parentElement.parentElement.parentElement.parentElement.querySelector('.pl-video-edit-remove').click(); } else { window.clearInterval(i); }}, 500);}})();</textarea>

    <center>
    <a target="_blank" onClick="copy_function();" href="https://www.youtube.com/playlist?list=<?= playlist(data, sheetID); ?>">Open Youtube Playlist!</a>
    </center>
    <br>
    <br>
    <iframe id="ytplayer" type="text/html" width="1260" height="695" src='https://www.youtube.com/embed?listType=playlist&list=<?= playlist(data, sheetID); ?>' frameborder="0" allowfullscreen></iframe>
    <br>
    <!---
    <iframe id="playlist" width="0" height="0" src='https://www.youtube.com/playlist?list=<?= playlist(data, sheetID); ?>' frameborder="0" allowfullscreen></iframe>
    <input type="button" value="Copy function to clipboard." onClick="copy_function();">
    --->
  </body>
</html>