Automagic creation of computed properties from enumerable chains.

Enumerology is a bunch of useful Computed Property macros for working on enumerables.

Best I give you an example, eh?

var Movie = Em.Object.extend({
      castNames: Enumerology.create('cast').mapBy('name').sort().finalize(),
      characterNames: Enumerology.create('cast').mapBy('character').sort().finalize()
    });

var bttf = Movie.create({
      cast: [
        Em.Object.create({name: 'Michael J. Fox', character: 'Marty McFly'}),
        Em.Object.create({name: 'Christopher Lloyd', character: 'Doc Emmett Brown'}),
        Em.Object.create({name: 'Claudia Wells', character: 'Jennifer Parker'}),
      ]
    });

bttf.get('castNames')      // => ["Christopher Lloyd", "Claudia Wells", "Michael J. Fox"]
bttf.get('characterNames') // => ["Doc Emmett Brown", "Jennifer Parker", "Marty McFly"]

Download the production version or the development version.

In your web page:

<script src="dist/ember-enumerology.min.js"></script>

In order to create an Enumerology-created computed property you call Enumerology.create and pass as an argument the name of the collection property to depend on (the part you would stick in the property() call in a normal computed property)

You can then chain on as many transformations as you like (eg map or uniq) and then call finalize() on the end of the chain to create and return the computed property.

For example:

Ember.Object.extend({
  fruit: ['apple', 'apple', 'banana', 'pear'],
  uniqueFruitCount: Enumerology.create('fruit').uniq().length().finalize()
})

Enumerology supports a bunch of methods, which it calls "transforms" that can be applied to an enumerable. Most can be chained, although it obviously makes no sense to try and map the result of a method which returns an object, instead of an array (like first or any).

see: Ember.Enumerable#any

see: Ember.Enumerable#anyBy

see: Ember.Enumerable#compact

Removes any elements where a named property is empty, null or undefined.

• key - The name of the property to use for emptiness test.

see: Ember.Enumerable#contains

Returns true if the collection contains zero elements.

Shorthand for compactBy(key).empty()

• key - The name of the property to filter on.

see: Ember.Enumerable#every

see: Ember.Enumerable#everyBy

see: Ember.Enumerable#filter

see: Ember.Enumerable#filterBy

see: Ember.Enumerable#find

see: Ember.Enumerable#findBy

Returns the first element of the collection.

see: Ember.Enumerable#invoke

alias for empty

alias for emptyBy

Join a collection of strings with a given separator.

• separator - A string to use as the separator for each element. Defaults to ' '

Returns the last element of the collection.

Returns the number of elements in the collection.

see: Ember.Enumerable#map

see: Ember.Enumerable#mapBy

Returns true of the collection has one or more elements in it.

Shorthand for compactBy(key).nonEmpty()

• key - The name of the property to filter on.

see: Ember.Enumerable#reduce

see: Ember.Enumerable#reject

see: Ember.Enumerable#rejectBy

see: Array#reverse

note: Enumerology never mutates the original collection, so a new copy of the array is created before being passed into reverse.

see: Ember.Enumerable#setEach

note: Ember's setEach method doesn't return the original collection, however Enumerology's does to enable chaining.

see: Array#slice

see: Array#sort

notes:

• Enumerology never mutates the original collection, so a new copy of the array is created before being passed into sort.
• By default JavaScript sorts collections "lexigraphically", ie in alphabetical order (if no compareFunction is provided).

see also: sortNumerically

Sorts a collection of objects by the value of a named property.

• key - the property name to sort on.
• compareFunction - a function to define a custom sort operation. See: Array#sort

notes:

• Enumerology never mutates the original collection, so a new copy of the array is created before being passed into sortBy.
• By default JavaScript sorts collections "lexigraphically", ie in alphabetical order (if no compareFunction is provided).

see also: sortNumericallyBy

Sorts a collection of objects numerically (instead of lexigraphically, as JavaScript does by default).

see: Array#sort

Sorts a collection of objects numerically by the value of a named property.

• key the property name to sort on.

Take the first n elements from the collection.

• howMany - the number of elements to select from the collection.

Convert a collection of strings into a sentence.

• conjunction - The word to use to separate the last element of the list. Defaults to 'and'.
• oxfordComma - Boolean. Whether or not to put a comma immediately before the conjunction. Defaults to false.

see: Ember.Enumerable#uniq

see: Ember.Enumerable#without

Copyright (c) 2013 Resistor Ltd. Licensed under the MIT license.