gistfile1.rb

class PostsController < ApplicationController

  before_action :load_post, only: [:edit, :show, :update, :destroy]

  def index
    load_posts
  end

  def new
    build_post
  end

  def create
    build_post
    save_post or render 'new'
  end

  def edit
    load_post
    build_post
  end

  def show
    load_post
  end

  def update
    load_post
    build_post
    save_post or render 'edit'
  end

  def destroy
    load_post
    @post.destroy
    redirect_to posts_path
  end

  private

  def post_params
  end

  def load_posts
    @posts ||= post_scope.to_a
  end

  def build_post
    @post ||= post_scope.build
    @post.attributes = post_params
  end

  def save_post
    if @post.save
      redirect_to @post
    else
      render 'new'
    end
  end

  def load_post
    if params[:id].present?
      post_scope.find(params[:id]) rescue ActiveRecord::RecordNotFound
    else
      Post.none
    end
  end

  def post_scope
    Post.all
  end
end