Rails開発を面白くするアクションコントローラーの5大機能とルーティングの基本：開発現場でちゃんと使えるRails 4入門（7）（3/3 ページ）

def book_pdf
  @book = Book.find(params[:id])
  send_file @book.pdf_path,
                 filename: @book.title,
                 type: ‘application/pdf’
                 disposition: ‘inline’
end

def book_pdf
  @book = Book.find(params[:id])
  send_data @book.body,
                 filename: @book.title,
                 type: ‘application/text’
end

resources :books
 
# rake routes コマンドの実行結果
    books GET    /books(.:format)          books#index
          POST   /books(.:format)          books#create
 new_book GET    /books/new(.:format)      books#new
edit_book GET    /books/:id/edit(.:format) books#edit
     book GET    /books/:id(.:format)      books#show
          PATCH  /books/:id(.:format)      books#update
          PUT    /books/:id(.:format)      books#update
          DELETE /books/:id(.:format)      books#destroy

resources :books, only: %i(index)
resources :users, except: %i(index new create edit update destroy)
 
# rake routes コマンドの実行結果
books GET    /books(.:format)          books#index
 user GET /users/:id(.:format) users#show

resources :users, except: %i(index new create edit update destroy) do
  get ‘booking’, on: :collection
  post 'message', on: :member
  resources :books, only: %i(index)
end
 
# rake routes コマンドの実行結果
booking_users GET  /users/booking(.:format)        users#booking
 message_user POST /users/:id/message(.:format)    users#message
   user_books GET  /users/:user_id/books(.:format) books#index
         user GET  /users/:id(.:format)            users#show

resources :users, except: %i(index new create edit update destroy) do
  collection do
    get ‘booking’
  end
  
  member do
    post 'message', on: :member
  end
  
  resources :books, only: %i(index)
end

namespace :admin do
  resources :books
end
 
# rake routes コマンドの実行結果
admin_books GET  /admin/books(.:format)          admin/books#index
 
（以下略）

root “books#index”