Userscript: MVGroup Downloads All Magnets Button (Forums)

// ==UserScript==
// @name         MVGroup Magnets
// @version      6.7.4
// @author       emy
// @match        http://forums.mvgroup.org/index.php?showtopic=*
// @require      https://code.jquery.com/jquery-3.2.1.min.js
// ==/UserScript==

$magnet_list = [];

function constructButton($torrent_list)
{
  $button_html = '<div id="magnet-dl-all">Download All Magnets (' + $magnet_list.length + ')</div>';

  $frame = '<iframe style="display:none" name="magnetframe"></iframe>';

  $(document).find('iframe').prev().after($frame + $button_html);

  $(document).find('#magnet-dl-all').css({
    'display' : 'inline-block',
    'background-color' : '#c93030',
    'padding' : '5px',
    'color' : 'white',
    'border-radius' : '3px',
    'cursor' : 'pointer',
    'font-weight' : 'bold',
  });
}

function fetchMagnetUrls($torrent_list)
{
  $torrent_list.find(".magnetlink").each(function()
  {
    $magnet_url = $(this).attr('href');
    $magnet_list[$magnet_list.length] = $magnet_url;
  });

  if($magnet_list.length > 0)
  {
    constructButton($torrent_list);
  }
}

function waitForTorrentList()
{
  if($(document).find('iframe').contents().find('#torrentlist').length >= 1)
  {
    fetchMagnetUrls($(document).find('iframe').contents().find('#torrentlist'));
  } else {
    setTimeout(waitForTorrentList, 1000);
  }
}

$(document).ready(function()
{
  waitForTorrentList();

  $(document).on('click', '#magnet-dl-all', function()
  {
    jQuery.each($magnet_list, function(index, item)
    {
      window.open(item, 'magnetframe');
    });
  });

  $(document).on('mouseenter', '#magnet-dl-all', function()
  {
    $(this).css('background-color', 'rgb(221, 29, 29)');
  });

  $(document).on('mouseleave', '#magnet-dl-all', function()
  {
    $(this).css('background-color', '#c93030');
  });
});