NinSheetMusic MIDI player

nsm_player.user.js

// ==UserScript==
// @name     NinSheetMusic MIDI player
// @version  1
// @grant    none
// @include  https://www.ninsheetmusic.org/browse/series/*
// ==/UserScript==


function injectJs(url, callback) {
    script = document.createElement('script');
    script.type = 'text/javascript';
    script.async = true;
    script.onload = callback;
    script.src = url;
    document.getElementsByTagName('head')[0].appendChild(script);
}

injectJs('https://www.midijs.net/lib/midi.js', function() {
	injectJs('https://code.jquery.com/jquery-3.3.1.slim.min.js', function() {
    unsafeWindow.eval(`
        $('.content tbody tr td[width]:last-child').each(function(idx, elem) {
          var td = $(this);
          var href = td.children('a').attr('href');

          td.after(
            $('<td>').append(
              $('<a>').css('cursor', 'pointer').html('▶').click(function() {
                MIDIjs.play(href);
              })
            )
          ).after(
            $('<td>').append(
              $('<a>').css('cursor', 'pointer').html('⏸').click(function() { MIDIjs.stop() })
            )
          );
        });
        console.log('loaded script');
        `);
  })
});