Sequential loading with jquery Deferred

gistfile1.js

// a is a jquery collection
// fn is a function that returns a promise

function loadItems(a, fn) {
  var d = $.Deferred();
  var next = d.promise();

  a.each(function () {
    var that = this;
    next = next.pipe(function () {
      return fn(that);
    });
  });

  d.resolve();
  return next;
}