var baseCallback = require('../internal/baseCallback'), baseMap = require('../internal/baseMap'), baseSortBy = require('../internal/baseSortBy'), compareAscending = require('../internal/compareAscending'), isIterateeCall = require('../internal/isIterateeCall'); /** * Creates an array of elements, sorted in ascending order by the results of * running each element in a collection through `iteratee`. This method performs * a stable sort, that is, it preserves the original sort order of equal elements. * The `iteratee` is bound to `thisArg` and invoked with three arguments: * (value, index|key, collection). * * If a property name is provided for `iteratee` the created `_.property` * style callback returns the property value of the given element. * * If a value is also provided for `thisArg` the created `_.matchesProperty` * style callback returns `true` for elements that have a matching property * value, else `false`. * * If an object is provided for `iteratee` the created `_.matches` style * callback returns `true` for elements that have the properties of the given * object, else `false`. * * @static * @memberOf _ * @category Collection * @param {Array|Object|string} collection The collection to iterate over. * @param {Function|Object|string} [iteratee=_.identity] The function invoked * per iteration. * @param {*} [thisArg] The `this` binding of `iteratee`. * @returns {Array} Returns the new sorted array. * @example * * _.sortBy([1, 2, 3], function(n) { * return Math.sin(n); * }); * // => [3, 1, 2] * * _.sortBy([1, 2, 3], function(n) { * return this.sin(n); * }, Math); * // => [3, 1, 2] * * var users = [ * { 'user': 'fred' }, * { 'user': 'pebbles' }, * { 'user': 'barney' } * ]; * * // using the `_.property` callback shorthand * _.pluck(_.sortBy(users, 'user'), 'user'); * // => ['barney', 'fred', 'pebbles'] */ function sortBy(collection, iteratee, thisArg) { if (collection == null) { return []; } if (thisArg && isIterateeCall(collection, iteratee, thisArg)) { iteratee = undefined; } var index = -1; iteratee = baseCallback(iteratee, thisArg, 3); var result = baseMap(collection, function(value, key, collection) { return { 'criteria': iteratee(value, key, collection), 'index': ++index, 'value': value }; }); return baseSortBy(result, compareAscending); } module.exports = sortBy;