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
• static inheritance
• 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
• Es6 Class supports
• 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[], staticInherit = true)

• staticInherit (boolean): whether static inheritance,defaults to true.

  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
• add the super_ property(the super ctor) to the ctor.
• add the __super__ property(the super's prototype) to the ctor for the coffeeScirpt super keyword.
• add the Class property(point to the current class) to the object's prototype.
  • just be care: the ctor may not be the current class.

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
  @static: 1
  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)
assert.equal MyClass.static, 1

inheritsDirectly(ctor, superCtor, staticInherit = true)

• staticInherit (boolean): whether static inheritance,defaults to true.

  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[], options:{ filter: number|function})

Mixin the methods and properties of the SuperCtor: Clone(Copy) all superCtor's properties(methods) to ctor.

• options:
  • filter: defaults to 0.
    • 0: copy all properties(methods)
    • 1: raise error if found a method using super
    • 2: skip these methods which using super
    • string[]: only name in the array of string will be copied.
    • function(name, value){return value} the callback function of filter.
      • name: the property name
      • value: the property value.

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

mixin all superCtors to ctor.

• duplication mixin or inheritance check
• NOTE::the methods in mixins using super() will jump to the old class(not stay on the class).
• The mixined properties(methods) are cloned(copied) from superCtors(includes the static members)
• The all mixined properties(methods) are the first parent's ctor(MixinCtor_)
  • eg, ctor -> MixinCtor_ -> original parents

## Coffee@2.x
mCallOrder = []
class Root

class C extends Root
  m: ->
    mCallOrder.push 'C'
    super

class A
  m: ->
    mCallOrder.push 'A'

class A1 extends A
  m: ->
    mCallOrder.push 'A1'
    super

class B
  inherits B, Root

class B1 extends B
  m: ->
    mCallOrder.push 'B1'
    super

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

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

isMixinedFrom(ctor, superCtor|superCtorName)

check the ctor whether is mixined from superCtor.

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

createCtor(name, args, body)

Create a constructor(class) dynamically.

• name(string): the class name
• args(any[]): the optional constructor's args.
• body(string): the optional constructor function body.

  const createClass = require('inherits-ex/lib/createCtor')
  const MyClass = createClass('MyClass', ['a', 'b'], 'this.sum = a + b');
  var my = new MyClass(1, 2);
  console.log(my.sum);

createObject(ctor, args...)

The helper function to create the object dynamically.

  var createObject = require('inherits-ex/lib/createObject')
  class MyClass {
    constructor(a,b) {
      this.sum = a + b;
    }
  }
  var o = creatObject(MyClass, 1, 2)
  console.log(o.sum)

NOTE: DO NOT SUPPORT ES6 Class

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 the object dynamically.

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

NOTE: DO NOT SUPPORT ES6 Class

createFunction(name, [args,] body[, scope[, values]])

• arguments:
  • name (String): the function name
  • args (Array): the function argument list. it's optional.
  • body (String): the function body.
  • ``scope` (Object|Array): the optional function scope.
    • ignore the values if it's an object.
    • the value is requierd if it's an array. It's the key's name list
  • value (Array): the optional function scope's value list. only for the scope is the Array.

The helper function to create the function dynamically.

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

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"