coalwater · May 9, 2015 11:25
diff --git a/null_book.rb b/null_book.rb
 class NullBook
  def title
    'No book exists'
  end
 end
diff --git a/order_class.rb b/order_class.rb
 class Order
  def book
    @book
  end
 end
diff --git a/order_view.rb b/order_view.rb
 @orders.each do |order|
  order.book.title
 end
diff --git a/order_view_patched.rb b/order_view_patched.rb
 @orders.each do |order|
  if @order.book.nil?
    'No Book exists'
  else
    order.book.title
  end
 end
diff --git a/order_with_nullbook.rb b/order_with_nullbook.rb
 class Order
  def book
    @book || NullBook.new
  end
 end
	@orders.each do \|order\|
	if @order.book.nil?
	'No Book exists'
	else
	order.book.title
	end
	end