Question

This is a helper function I define for creating properties in my classes:

###
# defines a property on an object/class
# modified from https://gist.github.com/746380
###
Object::public = (name, options = {}) ->
  options['default'] ?= null
  variable = options['default']
  getter = if typeof options['get'] is 'function' then options['get'] else -> variable
  setter = if typeof options['set'] is 'function' then options['set'] else (value) ->  variable = value

  config = {}
  config['get'] = getter if options['get']
  config['set'] = setter if options['set']
  config['configurable'] = no
  config['enumerable'] = yes

  Object.defineProperty @prototype, name, config

Inside a file I have the two classes below, Folds and _Folds, the latter being hidden with only the former exported (namespaced) to the global.

###
  Public exported fetcher for fold factory,
  being the only way through which to create folds.
###
class Folds
  _instance = undefined

  # static fetch property method
  @public 'Factory',
    get: -> _instance ?= new _Folds

###
  Encapsuled singleton factory for one-stop fold creation
###
class _Folds
  constructor: ->

  create: -> new Fold

Then when I try this, it returns false. Why?

console.log 'Factory' of Folds

The following is returning “function Folds() {}”

console.log Folds

I can’t call Folds.Factory.create() because Folds.Factory is undefined.

Answer 1

CoffeeScript’s in is for arrays (and array-like objects); of compiles to JavaScript’s in. So what you want is

console.log 'Factory' of Folds

That’s not the core problem, though: The core problem is that the public method you’re using actually defines a property with the given name on the class’ prototype, as the line

Object.defineProperty @prototype, name, config

tells us. So what you really want is

console.log 'Factory' of Folds.prototype  # should be true

which means that the Factory method will be available as a property of every Folds instance.