CoffeeScript Mixins

This package allows you to include other classes (or an object with functions) into a CoffeeScript class.

This allows for better code reuse in classes where you're already using inheritance or would just like to share functionality in modules.

View Demo

Usage

You'll need to require and bootstrap the mixins before any of your CoffeeScript class definitions.

Node

mixins = require 'coffeescript-mixins'
mixins.bootstrap() # Mixes in include on Function

Web

window.CoffeeScriptMixins.bootstrap();

After this initial setup you can utilize the @include method in any of your CoffeeScript classes.

Examples

Declaring a Mixin

You can create a mixin like any other CoffeeScript class. Give it some methods, utilize inheritance, or include another mixin.

# Typical mixin
class Mixin
  sharedMethod: ->
    return 'Hey!'

# With inheritance
class CoolMixin extends Mixin
  coolMethod: ->
    return 'Heya!'

# With other mixins
class MultiMixin
  @include CoolMixin

Including a mixin

You can include a mixin into a CoffeeScript class using the include class method.

class A
  @include Mixin

a = new A()
a.sharedMethod() # Hey!

Overriding Mixed In Functions

You can override mixed in functions and declare your own behavior:

class Mixin
  sharedMethod: ->
    console.log 'Cool…'

class A
  @include Mixin

  sharedMethod: ->
    # please don't console.log in my code.

You can also use super to call up to the mixed in function.

class Mixin
  sharedMethod: ->
    console.log 'Cool...'

class A
  @include Mixin

  sharedMethod: ->
    console.log 'Really...'
    super

###
Outputs:
  Really…
  Cool…
###
a = new A()
a.sharedMethod()

Notes

A mixed in function will take precedence over an inherited function, like so:

class Mixin
  sharedMethod: ->
    console.log 'Cool...'

class A
  sharedMethod: ->
    console.log 'Hey...'

class B extends A
  @include Mixin

###
Outputs:
  Cool...
###
b = new B()
b.sharedMethod()

Calling super in an override will not call up to the inherited class but will instead call up to the mixed in class:

class Mixin
  sharedMethod: ->
    console.log 'Cool...'

class A
  sharedMethod: ->
    console.log 'Hey...'

class B extends A
  @include Mixin

  sharedMethod: ->
    super

###
Outputs:
  Cool...
###
b = new B()
b.sharedMethod()