Hot or Not?

gistfile1.js

$scope.shortenInText = function () {
  var text = $scope.content.text || '';
  var PROTO_PTRN = /^https?:\/\//;
  var tokens = text.split(/\s/);

  _.chain(tokens)
  // get tokens that look like URLs
  .map(function(token) {
    if(PROTO_PTRN.test(token)) {
      return token;
    }
  })
  // remove duplicates
  .unique()
  // remove falsy values
  .compact()
  // make requests
  .map(function (url) {
    return shortenLink(url).then(function (shortLink) {
      return {
        original: url,
        shortLink: shortLink
      };
    });
  })
  // wait for all requests to complete
  .tap(function (promises) {
    return when.all(promises);
  })
  .value()
  // update text content with short links
  .then(function (items) {
    $scope.$apply(function ($s) {
      var text = $s.content.text || '';
      _.each(items, function (item) {
        var ptrn = new RegExp(_.escapeRegExp(item.original), 'g');
        text = text.replace(ptrn, item.shortLink);
      });
      $s.content.text = text;
    });
  });
};