| /** |
| * Lo-Dash 2.4.1 (Custom Build) <http://lodash.com/> |
| * Build: `lodash modularize modern exports="node" -o ./modern/` |
| * Copyright 2012-2013 The Dojo Foundation <http://dojofoundation.org/> |
| * Based on Underscore.js 1.5.2 <http://underscorejs.org/LICENSE> |
| * Copyright 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors |
| * Available under MIT license <http://lodash.com/license> |
| */ |
| var compareAscending = require('../internals/compareAscending'), |
| createCallback = require('../functions/createCallback'), |
| forEach = require('./forEach'), |
| getArray = require('../internals/getArray'), |
| getObject = require('../internals/getObject'), |
| isArray = require('../objects/isArray'), |
| map = require('./map'), |
| releaseArray = require('../internals/releaseArray'), |
| releaseObject = require('../internals/releaseObject'); |
| |
| /** |
| * Creates an array of elements, sorted in ascending order by the results of |
| * running each element in a collection through the callback. This method |
| * performs a stable sort, that is, it will preserve the original sort order |
| * of equal elements. The callback is bound to `thisArg` and invoked with |
| * three arguments; (value, index|key, collection). |
| * |
| * If a property name is provided for `callback` the created "_.pluck" style |
| * callback will return the property value of the given element. |
| * |
| * If an array of property names is provided for `callback` the collection |
| * will be sorted by each property value. |
| * |
| * If an object is provided for `callback` the created "_.where" style callback |
| * will return `true` for elements that have the properties of the given object, |
| * else `false`. |
| * |
| * @static |
| * @memberOf _ |
| * @category Collections |
| * @param {Array|Object|string} collection The collection to iterate over. |
| * @param {Array|Function|Object|string} [callback=identity] The function called |
| * per iteration. If a property name or object is provided it will be used |
| * to create a "_.pluck" or "_.where" style callback, respectively. |
| * @param {*} [thisArg] The `this` binding of `callback`. |
| * @returns {Array} Returns a new array of sorted elements. |
| * @example |
| * |
| * _.sortBy([1, 2, 3], function(num) { return Math.sin(num); }); |
| * // => [3, 1, 2] |
| * |
| * _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math); |
| * // => [3, 1, 2] |
| * |
| * var characters = [ |
| * { 'name': 'barney', 'age': 36 }, |
| * { 'name': 'fred', 'age': 40 }, |
| * { 'name': 'barney', 'age': 26 }, |
| * { 'name': 'fred', 'age': 30 } |
| * ]; |
| * |
| * // using "_.pluck" callback shorthand |
| * _.map(_.sortBy(characters, 'age'), _.values); |
| * // => [['barney', 26], ['fred', 30], ['barney', 36], ['fred', 40]] |
| * |
| * // sorting by multiple properties |
| * _.map(_.sortBy(characters, ['name', 'age']), _.values); |
| * // = > [['barney', 26], ['barney', 36], ['fred', 30], ['fred', 40]] |
| */ |
| function sortBy(collection, callback, thisArg) { |
| var index = -1, |
| isArr = isArray(callback), |
| length = collection ? collection.length : 0, |
| result = Array(typeof length == 'number' ? length : 0); |
| |
| if (!isArr) { |
| callback = createCallback(callback, thisArg, 3); |
| } |
| forEach(collection, function(value, key, collection) { |
| var object = result[++index] = getObject(); |
| if (isArr) { |
| object.criteria = map(callback, function(key) { return value[key]; }); |
| } else { |
| (object.criteria = getArray())[0] = callback(value, key, collection); |
| } |
| object.index = index; |
| object.value = value; |
| }); |
| |
| length = result.length; |
| result.sort(compareAscending); |
| while (length--) { |
| var object = result[length]; |
| result[length] = object.value; |
| if (!isArr) { |
| releaseArray(object.criteria); |
| } |
| releaseObject(object); |
| } |
| return result; |
| } |
| |
| module.exports = sortBy; |