lodash/sortBy.js

define(['./_baseFlatten', './_baseOrderBy', './isArray', './_isFlattenableIteratee', './_isIterateeCall', './rest'], function(baseFlatten, baseOrderBy, isArray, isFlattenableIteratee, isIterateeCall, rest) {

  /**
   * Creates an array of elements, sorted in ascending order by the results of
   * running each element in a collection thru each iteratee. This method
   * performs a stable sort, that is, it preserves the original sort order of
   * equal elements. The iteratees are invoked with one argument: (value).
   *
   * @static
   * @memberOf _
   * @since 0.1.0
   * @category Collection
   * @param {Array|Object} collection The collection to iterate over.
   * @param {...(Array|Array[]|Function|Function[]|Object|Object[]|string|string[])}
   *  [iteratees=[_.identity]] The iteratees to sort by.
   * @returns {Array} Returns the new sorted array.
   * @example
   *
   * var users = [
   *   { 'user': 'fred',   'age': 48 },
   *   { 'user': 'barney', 'age': 36 },
   *   { 'user': 'fred',   'age': 40 },
   *   { 'user': 'barney', 'age': 34 }
   * ];
   *
   * _.sortBy(users, function(o) { return o.user; });
   * // => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]
   *
   * _.sortBy(users, ['user', 'age']);
   * // => objects for [['barney', 34], ['barney', 36], ['fred', 40], ['fred', 48]]
   *
   * _.sortBy(users, 'user', function(o) {
   *   return Math.floor(o.age / 10);
   * });
   * // => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]
   */
  var sortBy = rest(function(collection, iteratees) {
    if (collection == null) {
      return [];
    }
    var length = iteratees.length;
    if (length > 1 && isIterateeCall(collection, iteratees[0], iteratees[1])) {
      iteratees = [];
    } else if (length > 2 && isIterateeCall(iteratees[0], iteratees[1], iteratees[2])) {
      iteratees = [iteratees[0]];
    }
    iteratees = (iteratees.length == 1 && isArray(iteratees[0]))
      ? iteratees[0]
      : baseFlatten(iteratees, 1, isFlattenableIteratee);

    return baseOrderBy(collection, iteratees, []);
  });

  return sortBy;
});