custom_open_struct.rb

require 'ostruct'
require 'pp'

class NewStruct < OpenStruct
  
  def self.new(hash)
    if hash.nil? || hash.empty?
      return nil
    else
      super(hash)
    end
  end
  
end

class InitStruct < OpenStruct
  
  def initialize(hash)
    if hash.nil? || hash.empty?
      return nil
    else
      super(hash)
    end
  end
  
end

puts "Instantiating OpenStruct..."
empty_struct = OpenStruct.new({})
pp empty_struct # returns an empty OpenStruct object

puts "Instantiating NewStruct..."
new_empty_struct = NewStruct.new({})
pp new_empty_struct # returns nil, the desired behavior

puts "Instantiating InitStruct..."
init_empty_struct = InitStruct.new({})
pp init_empty_struct # throws an exception