Add regex filter button for Public/Federated TimeLines

mastodon_universal_regex_filter.js

(function (g) {
  var d = g.document
      filter = prompt('Feed me a filtering regex:'),
      regex = new RegExp(filter, 'gi');
      display = function (value) {
        [].forEach.call(d.querySelectorAll('.status'), function (n) {
          var c, t;
          if (value !== 'block') {
            c = n.querySelector('.status__content');
            t = c.innerText || c.textContent;
            if (t.search(regex) < 0) return;
          }
          n.style.display = value;
        });
      };

  if ((g || {}).__ob) {
    g.__ob.disconnect();
    display('block');
  }

  if (filter === '') return;

  g.__ob = new MutationObserver(function () {
    display('none');
  });

  g.__ob.observe(d.body, {
    attributes: true,
    childList: true,
    characterData: true,
    subtree: true
  });
})(this);