Code snippet for dynamic model definition within a specific module.

const_missing.rb

# class Post < ActiveRecord::Base
#   #code
# end
#
# class Backend::Post < Post   # we don't want to define it in each model file.
# end

module Backend
  def self.const_missing(klass)
    klass = klass.to_s
    
    if Backend.const_defined?(klass)
      const_get(klass)
    else
      const_set(klass, ActiveRecord.const_get(klass))
    end

  end
end

#  Backend::Post
#  #=> Post
#
# Backend::Foo
# #=> NameError: uninitialized constant Backend::Foo