Simple controller

books_controller.rb

# This is generated using toy_scaffold,
# and is meant for learning purposes only.
# It aims for more clarity for beginners, therefore
# sacrifices some best practices and DRY principle.

class BooksController < ApplicationController
  # GET /books
  # View file is at app/views/books/index.html.erb
  def index
    @books = Book.all
  end

  # GET /books/1
  # View file is at app/views/books/show.html.erb
  def show
    @book = Book.find(params[:id])
  end

  # GET /books/new
  # View file is at app/views/books/new.html.erb
  def new
    @book = Book.new
  end

  # GET /books/1/edit
  # View file is at app/views/books/edit.html.erb
  def edit
    @book = Book.find(params[:id])
  end

  # POST /books
  def create
    @book = Book.new(book_params)

    if @book.save
      redirect_to @book, notice: 'Book was successfully created.'
    else
      render :new
    end
  end

  # PATCH/PUT /books/1
  def update
    @book = Book.find(params[:id])

    if @book.update(book_params)
      redirect_to @book, notice: 'Book was successfully updated.'
    else
      render :edit
    end
  end

  # DELETE /books/1
  def destroy
    @book = Book.find(params[:id])

    @book.destroy
    redirect_to books_url, notice: 'Book was successfully destroyed.'
  end

  private

    # Only allow a trusted parameter "white list" through.
    def book_params
      params.require(:book).permit(:title)
    end
end