Array sortBy

Powerful mechanism to sort arrays or array of objects by one or more properties. You can also specify a custom comparer function.

By default it has support for some accented characters (see mapAccents).

Content

1. Getting started
2. Including the library
3. Examples

Getting started

To include this library into your package manager with npm or yarn

# with npm
$ npm install array-sort-by

# with yarn
$ yarn add array-sort-by

The sortBy function has the following signature:

/**
 * @param  {Array} array: the list of elements to sort
 * @param  {Function} parser: transforms each item and specifies the sorting mode
 * @return {Array}
 */
sortBy(array: Array) : Array
sortBy(array: Array, parser: Function) : Array

If the parameter parser is not provided, then the array is sorted using the default implementation of Array.prototype.sort().

Otherwise, the parameter parser is a function that transforms each element being iterated and sets the sorting rules: ascending or descending. Here you can specify the way of sorting by multiple properties.

The parser callback has the following signature:

/**
 * @param  {Any} item: the element being iterated over the list
 * @param  {Number} index: the index of the element in the list
 * @return {Any}
 */
parser(item: Any, index: Number) : Any
parser(item: Any) : Any

See examples in the section Examples

mapAccents

A new static method mapAccents has been added to the sortBy function. This method allows to register a map of accented characters in order to sort the string accordingly.

Signature:

/**
 * @param {String} accents: a string with accented characters
 * @param {String} replacements: a string with the replacement for each accent
 */
sortBy.mapAccents(accents: String, replacements: String) : void

Problem solved: when you try to order strings with non ASCII characters like this: ['é', 'a', 'ú', 'c'], you will obtain strange results after sorting the array: ['c', 'e', 'á', 'ú']. That happens because by default the method Array.prototype.sort() does not work correctly with accented characters.

But the static method mapAccents comes to the rescue, because it has an internal mapping with some accented characters and their replacements:

// accents
"ÂâÀàÁáÄäÃãÅåÊêÈèÉéËëÎîÌìÍíÏïÔôÒòÓóÖöÕõÛûÙùÚúÜüÑñÝýÿ",
"AaAaAaAaAaAaEeEeEeEeIiIiIiIiOoOoOoOoOoUuUuUuUuNnYyy"
// replacements

You also may extend the accented characters and register a new set of special characters with their respective replacements:

// register special characters
sortBy.mapAccents(
  'ª@$',
  'aas',
);

const arr = ['$impson', 'Cªl@bazä', 'M@ría', 'Cal@bªzA'];
sortBy(arr);
/**
 * expected:
 * ["Cªl@bazä", "Cal@bªzA", "M@ría", "$impson"]
 *
 * translated as:
 * ["CALABAZA", "CALABAZA", "MARIA", "SIMPSON"]
 */

sortBy(arr, item => `DESC:${item}`);
/**
 * expected:
 * ["$impson", "M@ría", "Cal@bªzA", "Cªl@bazä"]
 *
 * translated as:
 * ["SIMPSON", "MARIA", "CALABAZA", "CALABAZA"]
 */

In the example above, after calling sortBy.mapAccents() we extended the internal mapping, by adding the new accents and their replacements at the beginning of the mapping, honoring the user mapping first:

// accents: added "ª@$"
"ª@$ÂâÀàÁáÄäÃãÅåÊêÈèÉéËëÎîÌìÍíÏïÔôÒòÓóÖöÕõÛûÙùÚúÜüÑñÝýÿ"
"aasAaAaAaAaAaAaEeEeEeEeIiIiIiIiOoOoOoOoOoUuUuUuUuNnYyy"
// replacements

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Including the library

array-sort-by can be included directly from a CDN in your site:

<!-- from unpkg.com -->
<script src="https://unpkg.com/array-sort-by/dist/sort-by.min.js"></script>
<!-- from unpkg.com, including polyfills -->
<script src="https://unpkg.com/array-sort-by/dist/sort-by-full.min.js"></script>

<!-- from rawgit.com -->
<script src="https://cdn.rawgit.com/jherax/array-sort-by/1.2.1/dist/sort-by.min.js"></script>
<!-- from rawgit.com, including polyfills -->
<script src="https://cdn.rawgit.com/jherax/array-sort-by/1.2.1/dist/sort-by-full.min.js"></script>

In the above case, the function sortBy is included as global object in the browser.

As sortBy is built as UMD (Universal Module Definition), it can be included from module loaders such as CommonJS, ES2015 Imports or AMD RequireJS.

CommonJS

var sortBy = require('array-sort-by');

ES2015 Imports

import sortBy from 'array-sort-by';

AMD

// using RequireJS
requirejs.config({
  paths: {
    // remove the extension .js
    'array-sort-by': '<PATH>/sort-by.min'
  }
});
require(['array-sort-by'], function(sortBy) {
  sortBy(someArray);
});

See an example with RequireJS here: http://jsfiddle.net/FdKTn/75/

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Examples

Default sorting (ASC)

let arr = [10, 8, 5, 3, 0, 7, 4, 5, 1];
sortBy(arr);

/**
 * expected:
 * [0, 1, 3, 4, 5, 5, 7, 8, 10]
 */

Sorting DESC: numbers

let arr = [5, 1, 8, 0, 3, 7, 10, 4, 3, 8];
sortBy(arr, n => -n);

/**
 * expected:
 * [10, 8, 8, 7, 5, 4, 3, 3, 1, 0]
 */

Sorting DESC: date-strings as Date

let arr = ['1983/03/06', '1980/12/24', '1985/08/31', '1983/03/05'];
sortBy(arr, (s) => -new Date(s));

/**
 * expected:
 * ["1985/08/31", "1983/03/06", "1983/03/05", "1980/12/24"]
 */

Sorting DESC: strings

Because we use the minus (-) symbol to specify a descending order, it would produce a NaN value if used with a String value. So the flag "desc:" (not case sensitive) is prefixed to the string value in the parser callback.

var arr = ['único', 'cosas', 'Árbol', 'fútbol', 'algo'];

sortBy(arr, item => 'desc:' + item);
/**
 * expected:
 * ["único", "fútbol", "cosas", "Árbol", "algo"]
 */

// sorting ASC: accented words
sortBy(arr);
/**
 * expected:
 * ["algo", "Árbol", "cosas", "fútbol", "único"]
 */

Sorting ASC: accented words by @text

var arr = [
  { id: 10, text: 'Woche' },
  { id: 20, text: 'wöchentlich' },
  { id: 30, text: 'wäre' }
];

sortBy(arr, item => item.text);

/**
 * expected:
 * [
 *   { id: 30, text: "wäre" },
 *   { id: 10, text: "Woche" },
 *   { id: 20, text: "wöchentlich" }
 * ]
 */

Sorting DESC by @id, after ASC by @dob (as Date)

let arr = [
  { id: 8, dob: '1985/08/31' },
  { id: 2, dob: '1980/12/24' },
  { id: 5, dob: '1983/03/06' },
  { id: 8, dob: '1983/03/06' }
];

sortBy(arr, (o) => [-o.id, new Date(o.dob)]);

/**
 * expected:
 * [
 *   { id: 8, dob: "1983/03/06" },
 *   { id: 8, dob: "1985/08/31" },
 *   { id: 5, dob: "1983/03/06" },
 *   { id: 2, dob: "1980/12/24" }
 * ]
 */

Sorting DESC by @name

let arr = [
  { id: 4, name: 'Pedro' },
  { id: 6, name: 'Lucía' },
  { id: 7, name: 'paco' },
  { id: 3, name: 'luis' }
];

sortBy(arr, item => `DESC:${item.name}`);

/**
 * expected:
 * [
 *   { id: 4, name: "Pedro" },
 *   { id: 7, name: "paco" },
 *   { id: 3, name: "luis" },
 *   { id: 6, name: "Lucía" }
 * ]
 */

Sorting ASC by @name, after DESC by @age, after ASC by @id

let arr = [
  { id: 9, age: 26, name: 'pedro' },
  { id: 6, age: 21, name: 'Pedro' },
  { id: 7, age: 26, name: 'Maria' },
  { id: 2, age: 26, name: 'maría' }
];

sortBy(arr, item => [item.name, -item.age, item.id]);

/**
 * expected:
 * [
 *   { id: 2, age: 26, name: "maría" },
 *   { id: 7, age: 26, name: "Maria" },
 *   { id: 9, age: 26, name: "pedro" },
 *   { id: 6, age: 21, name: "Pedro" }
 * ]
 */

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Versioning

This projects adopts the Semantic Versioning (SemVer) guidelines:

<MAJOR>.<MINOR>.<PATCH>

Given a version number MAJOR.MINOR.PATCH, increment the:

1. MAJOR version when you make incompatible API changes.
2. MINOR version when you add functionality in a backwards-compatible manner.
3. PATCH version when you make backwards-compatible bug fixes.

Issues

To report an issue and keep traceability of bug-fixes, please report to:

• https://github.com/jherax/array-sort-by/issues

License

This project has been released under the ISC license. This license applies ONLY to the source of this repository and does not extend to any other distribution, or any other 3rd party libraries used in a repository. See LICENSE file for more information.