function getTweets(id) {
  try {
    var widget, json, tweets, regex, tweet, list, time, url, when, rss, heading, title, link;

    title = 'Twitter RSS Feed :: ' + id;
    link = 'http://www.labnol.org/#' + id;

    // This the ID of your Twitter widget
    url = 'http://cdn.syndication.twimg.com/widgets/timelines/' + id;

    widget = UrlFetchApp.fetch(url);
    json = Utilities.jsonParse(widget);

    // If the Twitter widget doesn't exist, do nothing
    if (!json.body) {
      return;
    }

    // Remove all whitespaces from the Twitter's JSON response
    tweets = json.body.replace(/\s+/g, ' ');

    // Get the Feed Title and URL from the response heading (H1)
    regex = new RegExp(/<h1[^>]*>(.*?)<\/h1>/gi);

    if ((heading = regex.exec(tweets)) !== null) {
      regex = RegExp(/href="(.*?)"/gi);
      link = regex.exec(heading[1])[1];

      regex = RegExp(/title="(.*?)"/gi);
      if ((title = regex.exec(heading[1])) !== null) {
        title = title[1];
      }
    }

    rss = '<?xml version="1.0"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">';
    rss += ' <channel><title>' + title + '</title>';
    rss += ' <link>' + link + '</link>';
    rss += ' <atom:link href="http://www.labnol.org/#' + id + '" rel="self" type="application/rss+xml" />';
    rss +=
      ' <description>' +
      title +
      ' :: RSS Feed for Twitter widget #' +
      id +
      ' generated by Google Scripts.</description>';

    regex = RegExp(/<ol[^>]*>(.*?)<\/ol>/gi);

    if ((list = regex.exec(tweets)) !== null) {
      // Remove all the extra classes, DIV tags, SPAN tags from the tweets.
      list = list[1]
        .replace(/<div class=\"(header|footer|detail-expander|retweet-credit)[^>]*>(.*?)<\/div>/gi, '')
        .replace(/<time[^>]*>(.*?)<\/time>/gi, '')
        .replace(
          /data-tweet-id=".*?"|class=".*?"|rel=".*?"|title=".*?"|target=".*?"|data-expanded-url=".*?"|data-query-source=".*?"|dir=".*?"|data-pre-embedded=".*?"/gi,
          ''
        );

      regex = RegExp(/<li[^>]*>(.*?)<\/li>/gi);

      while ((tweets = regex.exec(list)) !== null) {
        tweet = tweets[1]
          .replace(/&nbsp;/g, ' ')
          .replace(/\s+/g, ' ')
          .replace(/<\s*(div|span|b|p)[^>]*>/gi, '')
          .replace(/<\s*\/\s*(div|span|b|p)[^>]*>/gi, '');

        // Extract the Date and Time of the tweet
        time = RegExp(/<a\s+href="(.*)"\s+data-datetime="(.*)"\s*><\/a>/gi);

        if ((time = time.exec(tweet)) !== null) {
          url = time[1];
          when = time[2];
          tweet = tweet.replace(/<a[^>]*>\s*<\/a>/gi, '');

          rss += '<item>';
          rss += ' <title>' + url.split('/')[3] + ': ' + tweet + '</title>';
          rss += ' <pubDate>' + when.replace('T', ' ') + '</pubDate>';
          rss += ' <guid>' + url + '</guid>';
          rss += ' <link>' + url + '</link>';
          rss += ' <description>' + tweet + '</description>';
          rss += '</item>';
        }
      }
    }

    rss += '</channel></rss>';
    return rss;
  } catch (e) {
    Logger.log(e.toString());
  }
}

function doGet(e) {
  var cache = CacheService.getPublicCache();
  var id = 'twitter' + e.queryString;
  var rss = cache.get(id);

  if (!rss) {
    rss = getTweets(e.queryString);
    cache.put(id, rss, 120); // Expire RSS Feed in 2 minutes
  }

  // Use the HTML Service in Google Apps Script to serve Twitter RSS Feeds
  return ContentService.createTextOutput(rss).setMimeType(ContentService.MimeType.RSS);
}