Module: Doodle::Factory

Defined in:
lib/doodle.rb

Overview

A factory function is a function that has the same name as a class which acts just like class.new. For example:

Cat(:name => 'Ren')

is the same as:

Cat.new(:name => 'Ren')

As the notion of a factory function is somewhat contentious [xref ruby-talk], you need to explicitly ask for them by including Factory in your base class:

class Base < Doodle::Root
  include Factory
end
class Dog < Base
end
stimpy = Dog(:name => 'Stimpy')

etc.

Constant Summary collapse

RX_IDENTIFIER = 
/^[A-Za-z_][A-Za-z_0-9]+\??$/

Class Method Summary collapse

Class Method Details

.factory(konst) ⇒ Object

create a factory function in appropriate module for the specified class



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# File 'lib/doodle.rb', line 870

def factory(konst)
  name = konst.to_s
  names = name.split(/::/)
  name = names.pop
  if names.empty?
    # top level class - should be available to all
    klass = Object
    method_defined = begin
                       method(name)
                       true
                     rescue Object
                       false
                     end
    
    if name =~ Factory::RX_IDENTIFIER && !method_defined && !klass.respond_to?(name) && !eval("respond_to?(:#{name})", TOPLEVEL_BINDING) 
      eval("def #{ name }(*args, &block); ::#{name}.new(*args, &block); end", ::TOPLEVEL_BINDING, __FILE__, __LINE__)
    end
  else
    klass = names.inject(self) {|c, n| c.const_get(n)}
    # todo[check how many times this is being called]
    if name =~ Factory::RX_IDENTIFIER && !klass.respond_to?(name)
      klass.module_eval("def self.#{name}(*args, &block); #{name}.new(*args, &block); end", __FILE__, __LINE__)
    end
  end
end

.included(other) ⇒ Object

inherit the factory function capability



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# File 'lib/doodle.rb', line 897

def included(other)
  super
  # make +factory+ method available
  factory other
end