Dependency Injection

bookshelf.rb

class BookShelf
  def initialize(books, magazines, flowers)
    @books     = books
    @magazines = magazines
    @flowers   = flowers
  end
  
  def find(book)
    @books.find(book)
  end
  
  def arrange
    @flowers.arrange
  end
end

classes_to_inject.rb

class Books
  #code
end

class Magazines
  #code
end

class Flowers
  #code
end

how_to_inject_them.rb

my_books = Books.new
my_magazines = Magazines.new
my_flowers = Flowers.new

my_bookshelf = BookShelf.new(my_books, my_magazines, my_flowers)