when.js

 (function ($, tag) {

      var flickrParams,
        vimeoParams,
        apiCalls = [];

      tag.photosets = null;
      tag.videos = null;

      if(opts.flickr && opts.flickr.api_key && opts.flickr.user_id) {
        flickrParams = {
          api_key: opts.flickr.api_key,
          user_id: opts.flickr.user_id,
          format: 'json',
          nojsoncallback: 1,
          primary_photo_extras: 'url_m'
        };

        apiCalls.push($.ajax({
          url: "/vms/api/flickr/flickr.photosets.getList?" + $.param(flickrParams)
        }).done(function (resp) {
          var ph = JSON.parse(resp);
          tag.photosets = ph.photosets.photoset;
        }));
      }

      if(opts.vimeo && opts.vimeo.token) {
        vimeoParams = {
          Authorization: "Bearer " + opts.vimeo.token
        };

        apiCalls.push($.ajax({
          url: "/vms/api/vimeo/",
          headers: vimeoParams
        }).done(function (resp) {
          var vids = JSON.parse(resp);
          tag.videos = vids.data;
        }))
      }

      if(apiCalls.length) {
        $.when.apply($, apiCalls).done(function() {
          tag.update();
        });
      }

    })(jQuery, this);