Optimization #2 - Controller Callbacks

app/controllers/posts_controller.rb

 class PostsController < ApplicationController
+  before_action :set_post, only: [:show, :destroy, :edit, :update]
   def index
   	@posts = Post.all
   end
 
   def show
-  	@post = Post.find_by(id: params[:id])
   end
 
   def new
@@ -22,22 +22,14 @@ class PostsController < ApplicationController
   end
 
   def destroy
-  	@post = Post.find_by(id: params[:id])
-  	if @post.present?
 		@post.destroy
-  		alert = "You have successfully deleted a post."
-  	else
-  		alert = "Post not found."
-  	end
-  	redirect_to posts_path, alert: alert
+  	redirect_to posts_path, alert: "You have successfully deleted a post."
   end
 
   def edit
-  	@post = Post.find_by(id: params[:id])
   end
 
   def update
-  	@post = Post.find_by(id: params[:id])
   	if @post.update(post_params)
   		redirect_to posts_path, notice: "You have successfully updated a post."
   	else
@@ -49,4 +41,9 @@ class PostsController < ApplicationController
   	def post_params
   		params.require(:post).permit!
   	end
+
+    def set_post
+      @post = Post.find_by(id: params[:id])
+      redirect_to posts_path, alert: "Post not found" if @post.nil?
+    end
 end