Advanced Coffeescript Mixins

gistfile1.coffee

window.include = (obj) ->
  console.log @
  @::[key] = value for key, value of obj; @

Module = {}
Module.Foo = (_super) ->
  overwriteMethod: -> "Foo"
  extendMethod: -> "Foo"
  fooMethod: -> @
  boundFooMethod: => @

class Baz

class Bar extends Baz
  include: (module, _super) ->
    for key, value of module.call(@, _super)
      @[key] = value unless @[key]?
    return @
  
  constructor: ->
    @include Module.Foo, Bar.__super__
    super

  overwriteMethod: -> "Bar"
  extendMethod: -> Module.Foo().extendMethod() + "Bar"
  barMethod: -> @
  boundBarMethod: => @

console.log "---"
b = new Bar
console.log "b = new Bar --->", b
console.log "b.overwriteMethod() --->", b.overwriteMethod()
console.log "b.extendMethod() --->", b.extendMethod()
console.log "---"
console.log "b.barMethod() --->", b.barMethod()
console.log "b.boundBarMethod() --->", b.boundBarMethod()
console.log "b.fooMethod() --->", b.fooMethod()
console.log "b.boundFooMethod() --->", b.boundFooMethod()
console.log "---"
console.log "b.barMethod.apply(null) --->", b.barMethod.apply(null)
console.log "b.boundBarMethod.apply(null) --->", b.boundBarMethod.apply(null)
console.log "b.fooMethod.apply(null) --->", b.fooMethod.apply(null)
console.log "b.boundFooMethod.apply(null) --->", b.boundFooMethod.apply(null)

gistfile2.txt

_extends = (child, parent) ->
  for key of parent
    if {}.hasOwnProperty.call(parent, key) then child[key] = parent[key]
  child::[key] = parent::[key] for key of parent.prototype
  child.__super__ = parent.prototype
  return child

class window.Foo
  overwriteMethod: -> "Foo"
  extendMethod: -> "Foo"
  fooMethod: -> @
  boundFooMethod: => @

class window.Baz

class window.Bar extends Baz
  @include: (module) ->
    _extends(@, module)
    _extends(module, _super)

  @include Foo

  overwriteMethod: -> "Bar"
  extendMethod: -> super + "Bar"
  barMethod: -> @
  boundBarMethod: => @

console.log "---"
window.b = new Bar
console.log "b = new Bar --->", b
console.log "b.overwriteMethod() --->", b.overwriteMethod()
console.log "b.extendMethod() --->", b.extendMethod()
console.log "---"
console.log "b.barMethod() --->", b.barMethod()
console.log "b.boundBarMethod() --->", b.boundBarMethod()
console.log "b.fooMethod() --->", b.fooMethod()
console.log "b.boundFooMethod() --->", b.boundFooMethod()
console.log "---"
console.log "b.barMethod.apply(null) --->", b.barMethod.apply(null)
console.log "b.boundBarMethod.apply(null) --->", b.boundBarMethod.apply(null)
console.log "b.fooMethod.apply(null) --->", b.fooMethod.apply(null)
console.log "b.boundFooMethod.apply(null) --->", b.boundFooMethod.apply(null)

gistfile3.txt

_ = {}
_.isFunction = (obj) -> typeof obj is 'function'
_.extend = (obj, args...) ->
  for source in args
    obj[prop] = source[prop] for prop of source if source?
  return obj

class window.Foo
  overwriteMethod: -> "Foo"
  extendMethod: -> "Foo"
  fooMethod: -> @
  boundFooMethod: => @

class window.Baz
  bazMethod: -> "Baz"

class window.Bar extends Baz
  @include: (mixin) ->
    if not mixin
      return throw 'Supplied mixin was not found'

    if not _
      return throw 'Underscore was not found'

    mixin = mixin.prototype if _.isFunction(mixin)

    # Make a copy of the superclass with the same constructor and use it
    # instead of adding functions directly to the superclass.
    if @.__super__
      tmpSuper = _.extend({}, @.__super__)
      tmpSuper.constructor = @.__super__.constructor

    @.__super__ = tmpSuper || {}

    # Copy function over to prototype and the new intermediate superclass.
    for methodName, funct of mixin when methodName not in ['included']
      @.__super__[methodName] = funct

      if not @prototype.hasOwnProperty(methodName)
        @prototype[methodName] = funct

    mixin.included?.apply(this)
    this

  @include Foo

  overwriteMethod: -> "Bar"
  extendMethod: -> super + "Bar"
  barMethod: -> @
  boundBarMethod: => @

console.log "---"
window.b = new Bar
console.log "b = new Bar --->", b
console.log "b.overwriteMethod() --->", b.overwriteMethod()
console.log "b.extendMethod() --->", b.extendMethod()
console.log "---"
console.log "b.barMethod() --->", b.barMethod()
console.log "b.boundBarMethod() --->", b.boundBarMethod()
console.log "b.fooMethod() --->", b.fooMethod()
console.log "b.boundFooMethod() --->", b.boundFooMethod()
console.log "b.bazMethod() --->", b.bazMethod()
console.log "---"
console.log "b.barMethod.apply(null) --->", b.barMethod.apply(null)
console.log "b.boundBarMethod.apply(null) --->", b.boundBarMethod.apply(null)
console.log "b.fooMethod.apply(null) --->", b.fooMethod.apply(null)
console.log "b.boundFooMethod.apply(null) --->", b.boundFooMethod.apply(null)