Method: Class#preallocate

Defined in:

lib/core/facets/class/preallocate.rb

#preallocate(aspect) ⇒ Object

Designate aspect modules to be added to a object at instantiation.

class Firetruck
  def put_out_fire(option)
    "Put out #{option}"
  end
end

module FastFiretruck
  def put_out_fire(option)
    super("very #{option}!")
  end
end

Firetruck.preallocate(FastFiretruck)

ft = Firetruck.new
ft.put_out_fire('fast') #=> "Put out very fast!"

This method is very similar to the idea of #prepend, but it has some limitations in that it works by overriding #new and #allocate and extends an object with the aspect modules on instantiation. A true #prepend implementation would not have to do this –but would be a natural part of the class heirarchy instead. For this reason, this method has been named #preallocate, rather than #prepend.

NOTE: This method is not a common core extension and is not loaded automatically when using require 'facets'.

CREDIT: Trans

Uncommon:

• require ‘facets/class/preallocate’

# File 'lib/core/facets/class/preallocate.rb', line 37

def preallocate(aspect)
  _new      = method(:new)
  _allocate = method(:allocate)
  (class << self; self; end).class_eval do
    define_method(:new) do |*args|
      o = _new.call(*args)
      o.extend aspect
      o
    end
    define_method(:allocate) do |*args|
      o = _allocate.call(*args)
      o.extend aspect
      o
    end
  end
end