x.js

gistfile1.js

/*
 * items -- array of objects with a 'location' field
 * userPrefs -- array of user-specified location labels, in user-specified order
 */
function sortByLocation(items, userPrefs) {
  return sortBy(items, userPrefs, 'location');
}

function sortBy(items, userPrefs, column) {
  items.sort(function(a,b) {
    var aIdx = userPrefs.indexOf(a[column]),
        bIdx = userPrefs.indexOf(b[column]);

    if (aIdx == -1) {
      aIdx = 1000000;
    }
    if (bIdx == -1) {
      bIdx = 1000000;
    }
    return (aIdx - bIdx);
  });
  return items;
}