inherits-ex

Inherits-Ex

Browser-friendly enhanced inheritance fully compatible with standard node.js inherits and coffee-script.

This package modifies and enhances the standard inherits from node.js util module in node environment. It also has a shim for old browsers with no Object.create support.

Differs from the standard implementation is:

• coffee-script supports
• multi-inheritances(inheritance chain) supports
• inherits at anytime.
  • you can not declare method/property before inherits in the standard way for it will replace the prototype object.
• duplication inheritance check
• more helper functions

The standard inherits implementation is in inherits-ex/lib/inheritsDirectly, of casue it's the coffee-script supports and browser-friendly.

API

inherits(ctor, superCtor|[superCtor, ...])

  var inherits = require('inherits-ex/lib/inherits')

The enhanced inherits implementation.

• coffee-script supports
• multi-inheritances(inheritance chain) supports
• inherits at anytime.
  • you can not declare method/property before inherits in the standard way for it will replace the prototype object.
• duplication inheritance check

usage

assert = require('assert')
inherits = require('inherits-ex/lib/inherits')
isInheritedFrom = require('inherits-ex/lib/isInheritedFrom')
log = console.log.bind console

class Root
  m: -> log('root')

class A
  inherits A, Root
  m: ->
  log('A')
  super

class B
  inherits B, Root
  m: -> log('B')
  super

class MyClass
  # MyClass -> A -> Root
  inherits MyClass, B
  # MyClass -> A -> B -> Root
  inherits MyClass, A

assert.notOk inherits(A, Root) #duplication inheritances prohibited.
assert.ok isInheritedFrom(MyClass, A)
assert.ok isInheritedFrom(MyClass, Root)
assert.ok isInheritedFrom(MyClass, B)

and the following codes do same thing:

class Root
  m: -> log('root')

class A
  m: ->
  log('A')
  super

class B
  m: -> log('B')
  super

class MyClass
  # create inheritances chain:
  # MyClass -> A -> B -> Root
  inherits MyClass, [A, B, Root]

assert.ok isInheritedFrom(MyClass, A)
assert.ok isInheritedFrom(MyClass, Root)
assert.ok isInheritedFrom(MyClass, B)

inheritsDirectly(ctor, superCtor)

  var inheritsDirectly = require('inherits-ex/lib/inheritsDirectly')

The standard inherits implementation in node.js environment with coffee-script supports and browser-friendly.

isInheritedFrom(ctor, superCtor|superCtorName, raiseError=false)

  var isInheritedFrom = require('inherits-ex/lib/isInheritedFrom')

return the superCtor's son if ctor is inherited from superCtor. else return false.

it will use the ctor.name to check whether inherited from superCtorName.

mixin(ctor, superCtor|[superCtor, ...])

  var mixin = require('inherits-ex/lib/mixin')

mixin all superCtors to ctor.

• duplication mixin or inheritance check
• the methods in mixins could super() across mixin classes.

mCallOrder = []
class Root
class C
  m: ->
    mCallOrder.push 'C'
    super
class A
  m: ->
    mCallOrder.push 'A'
class A1
  m: ->
    mCallOrder.push 'A1'
    super
class B
  inherits B, Root
class B1
  m: ->
    mCallOrder.push 'B1'
    super

inherits(C, Root).should.be.equal true, "C should inherits from Root"
inherits(B1, B).should.be.equal true, "B1 should inherits from B"
inherits(A1, A).should.be.equal true, "A1 should inherits from A"
mixin(B1, [A1, C]).should.be.equal true, 'mixin'
o = new B1()
o.m("a", 12) # call chain: B1::m -> C::m -> A1::m -> A::m
A::m.should.have.been.calledOnce
A::m.should.have.been.calledWith "a", 12
mCallOrder.should.be.deep.equal ['B1', 'C', 'A1', 'A']

The inheritance chain: B1 -> MixinCtor_ -> B -> Root All mixins will be added to MixinCtor_.

isMixinedFrom(ctor, superCtor|superCtorName)

  var isMixinedFrom = require('inherits-ex/lib/isMixinedFrom')

createObject(ctor, args...)

the helper function to create object.

  var createObject = require('inherits-ex/lib/createObject')

usage

class RefObject
  constructor: -> @initialize.apply @, arguments
class MyObject
  inherits MyObject, RefObject
  initialize: (@a,@b)->
    super

obj = createObject(MyObject, "a", "b")
#obj = new MyObject("a", "b") # it will have no property a and b.
assert.equal obj.a "a"
assert.equal obj.b "b"

createObjectWith(ctor, [args...])

the helper function to create object.

  var createObjectWith = require('inherits-ex/lib/createObjectWith')