composition

over

inheritance

object

class

ES6

But do we want to use it?

Inheritance

Composition

But inheritance

works pretty well

in your example!

OK, but

what happens if...

Engine

Amphicar

Tire

Mirror

Break

Seat

So how can I use

composition in Javascript?

With pure Javascript

(by Eric Elliott)

What's a stamp?

[A] composable factory function [...] that returns object instances[...].

https://github.com/stampit-org/stamp-specification

Installation

$ npm install stampit

Let's build a stamp

var stampit = require('stampit');

        stampit()

                .refs()

               .props()

.init()

.methods()

.static()

Add instance safe,

deeply merged properties to 

the objects created from the stamp

        stampit()

                .refs()

               .props()

.init()

.methods()

.static()

Add properties which are passed 

by reference to the objects

created from the stamp

        stampit()

                .refs()

               .props()

.init()

.methods()

.static()

Add private data

and privileged methods to 

the objects created from the stamp

        stampit()

                .refs()

               .props()

.init()

.methods()

.static()

Add public methods to 

the objects created from the stamp

        stampit()

                .refs()

               .props()

.init()

.methods()

.static()

Add methods to the stamp, 

but not to the objects

created from the stamp

DEMO

Additional facts

• also available for react
  https://github.com/stampit-org/react-stamp
   

• can convert javascript constructor functions
  with convertConstructor()
   

• created as example for the book
  'Programming Javascript Applications'
  (see http://bit.ly/pjsa-free-ebook)

I wanna tinker too

WISHIN' YA

GR8 FUN