posts_controller.rb

class PostsController < ApplicationController
  before_action :set_posts, only: [:index]
  before_action :set_new_post, only: [:new, :create]
  before_action :set_post, only: [:show, :edit, :update, :destroy]

  def new; end
  def show; end
  def edit; end
  def index; end

  def create
    @post.attributes = post_params

    if @post.save
      redirect_to @post
    else
      render :new
    end
  end

  def update
    if @post.update_attributes(post_params)
      redirect_to @post
    else
      render :edit
    end
  end

  def destroy
    @post.destroy!
    redirect_to :index
  end

  private

  def set_new_post
    @post = Post.new
  end

  def set_post
    @post = posts.find(params[:id])
  end

  def set_posts
    @posts = current_user.posts
  end

  def post_params
    @post_params ||= params.require(:post).permit(:title, :body)
  end
end