Mixable.coffee

A Ruby style mixin library for CoffeeScript & Javascript

Basic Usage

Mixable is a simple class that includes two class methods familiar to Rubyists: extend & include. To use Mixable, inherit from it like any other class in CoffeeScript. In the class body you can call extend to add class methods and include to add instance methods:

ClassMethods =
  classMethod: -> "a class method!"
  
InstanceMethods =
  instanceMethod: -> "an instance method!"
  
class Foo extends Mixable
  @extend  ClassMethods
  @include InstanceMethods
  
Foo.classMethod()          # => "a class method!"
new Foo().instanceMethod() # => "an instance method!"

Note: There is no support for super or method lookups. Mixable essentially just copies over properties from one object to another. If you need support for method lookups, look at Classify.

extend

extend(object, mixins...)

Adds the properties of each given mixin to the given object.

Mixin =
  method: -> "a method!"
  
foo = {}
extend foo, Mixin
foo.method() # => "a method!"

This can be used within a class body when you cannot extend the Mixable class.

Mixin =
  method: -> "a class method!"
  
class Foo
  extend @, Mixin
  
Foo.method() # => "a class method!"

If a class is given, its instance properties will be used, (not its class properties). This mimics the behavior of Ruby's mixin system.

class Mixin
  @classMethod: -> "a class method!"
  instanceMethod: -> "an instance method!"
  
class Foo
  extend @, Mixin
  
Foo.classMethod()    # => TypeError: Foo has no method 'classMethod'
Foo.instanceMethod() # => "an instance method!"

---

Mixable.extend(mixins...)

Adds the properties of each given mixin as class properties. Essentially a shortcut for extend @, mixins....

Mixin =
  method: -> "a class method!"
  
class Foo extends Mixable
  @extend Mixin
  
Foo.method() # => "a class method!"

include

include(object, mixins...)

Adds the properties of each given mixin as instance properties. This assumes the object is actually a class, and will throw a TypeError if it does not have a protoype.

Mixin =
  method: -> "an instance method!"
  
class Foo
  include @, Mixin
  
new Foo().method() # => "an instance method!"

If a class is given, its instance properties will be added as instance properties and its class properties will also be added as class properties. Essentially, all of its properties are added. Note: This is very different from how Ruby's mixin system works.

class Mixin
  @classMethod: -> "a class method!"
  instanceMethod: -> "an instance method!"
  
class Foo
  include @, Mixin
  
Foo.classMethod()          # => "a class method!"
new Foo().instanceMethod() # => "an instance method!"

---

Mixable.include(mixins...)

Adds the properties of each given mixin as instance properties. Essentially a shortcut for include @, mixins....

Mixin =
  method: -> "an instance method!"
  
class Foo extends Mixable
  @include Mixin
  
new Foo().method() # => "an instance method!"

---

Copyright (c) 2011 Pete Browne. See LICENSE for details.