gistfile1.txt

javascript:

/* You are granted a license to use, reproduce and create derivative works of this document. */

var isDirectiveMetadata = {viewport: true, referrer: true};
var isDirectiveLink = {stylesheet: true, shortcut: true, prerender: true, prefetch: true};

function collectMetadata () {
  var result = [];

  var els = document.querySelectorAll ('meta[name], meta[property]');
  for (var i = 0; i < els.length; i++) {
    var el = els[i];
    if (el.name) {
      var name = el.name.replace (/[A-Z]+/g, function (v) { return v.toLowerCase () });
      if (isDirectiveMetadata[name]) continue;
      result.push ({type: 'metadata', name: name, value: el.content});
    }
    if (el.hasAttribute ('property')) {
      result.push ({type: 'ogp', name: el.getAttribute ('property'), value: el.content});
    }
  }

  var els = document.querySelectorAll ('link[rel]');
  for (var i = 0; i < els.length; i++) {
    var el = els[i];
    var hasAlternate;
    var hasStylesheet;
    var rels = el.rel.replace (/[A-Z]+/g, function (v) { return v.toLowerCase () }).split (/[\x09\x0A\x0C\x0D\x20]+/).filter (function (v) {
      if (v === 'alternate') hasAlternate = true;
      if (v === 'stylesheet') hasStylesheet = true;
      return !isDirectiveLink[v];
    });
    if (rels.length === 0) continue;
    if (hasAlternate && hasStylesheet && rels.length === 1) continue;
    for (var j = 0; j < rels.length; j++) {
      result.push ({type: 'link', name: rels[j], value: el.href});
    }
  }

  return result.sort (function (a, b) { return a.name > b.name ? 1 : -1 });
} // collectMetadata

var meta = collectMetadata ();
console.log (meta);
showMetadata (meta);

function showMetadata (metas) {
  var container = document.createElement ('aside');
  container.innerHTML = '<style scoped>.meta-list { background: white; color: black; display: block; position: relative; float: none; border: 2px blue solid; padding: 0.5em; font-size: 1rem; font-style: normal; font-weight: normal; text-align: left; z-index: 21000000; }</style><table class=meta-list></table>';
  var listEl = container.lastChild;

  for (var i = 0; i < metas.length; i++) {
    var meta = metas[i];
    var li = document.createElement ('tr');
    li.innerHTML = '<th><code></code> (<span></span>)<td>';
    li.firstChild.firstChild.textContent = meta.name;
    li.firstChild.lastElementChild.textContent = meta.type;
    li.lastChild.textContent = meta.value;
    listEl.appendChild (li);
  }

  document.body.appendChild (container);
  container.scrollIntoView ();
} // showMetadata