multisort

Multitest

A small library for sorting arrays by multiple criteria.

Installation

npm install multisort --save

bower install multisort --save

Basic Usage

var input = [
  {firstName: "Kate", lastName: "Bush"},
  {firstName: "George", lastName: "Bush", suffix: "Junior"},
  {firstName: "George", lastName: "Orwell"},
  {firstName: "George", lastName: "Bush", suffix: "Senior"},
];
 
var criteria = [
  'firstName',
  '~lastName.length',
  'suffix.charAt(1)'
];
 
multisort(inputArray, criteria)
 
// input is now sorted by firstName (ascending), then lastName.length (descending),
// and finally suffix.charAt, called with 1 as the argument:
// [
//  {firstName: "George", lastName: "Orwell"},
//  {firstName: "George", lastName: "Bush", suffix: "Senior"},
//  {firstName: "George", lastName: "Bush", suffix: "Junior"},
//  {firstName: "Kate", lastName: "Bush"},
// ];

var input = [8, 7, 6, 5, 4, 3, 2, 1];
 
var criteria = [
  function(a) {return a % 2},
  function(a) {return a % 3},
  function(a) {return a}
];
 
multisort(input, criteria);
 
// input is now:
// [6, 4, 2, 8, 3, 1, 7, 5]

Partial Application

// Passing a single argument makes a sorting function that can then be applied to lists.
var sortByMod2AndMod3 = multisort([
  function(a) {return a % 2},
  function(a) {return a % 3},
  function(a) {return a}
]);
 
var input1 = [8, 7, 6, 5, 4, 3, 2, 1];
sortByMod2AndMod3(input1);
// input1 is [6, 4, 2, 8, 3, 1, 7, 5]
 
var input2 = [1, 5, 10, 25, 50, 100];
sortByMod2AndMod3(input2);
// input2 is [10, 100, 50, 1, 25, 5]

Features

Criteria types:

• Function: Applies the given function to each element, and the return values are sorted in ascending order, using < and >.
• String: Picks out the property indicated by the string, and sorts in ascending order, using < and >. Nested properties can be accessed with dot syntax, as in "property.subproperty.subsubproperty"
• !String or ~String: As above, but sorted in descending order. This works with the functional and existential operators below.
• String(arg1, arg2...): As above, but calls the indicated property as a function with the given arguments. Arguments are split by commas, trimmed, and parsed with JSON.parse.
• String?: As above, tests whether the property is null or undefined. Items without the property are sorted before items with it.

Tests

npm test

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code.

Release History

• 0.1.0 Initial release