index.html.erb

<% @posts.each do |post| %>
    <li>
    	#<%= link_to post.title, (post)  %> 
      <%= link_to 'show', post_path(post) %> 
    </li> <p> Comments (<%= post.comments.size %>) </p>
    <%= truncate post.body, length: 300 %>
  <% end %>
</div>
</div>

posts_controller.rb

class PostsController < ApplicationController
	 include PostsHelper
	 before_action :authenticate_user!

	def index
  		@posts = Post.all
  		#@post = Post.find(params[:id])
	end

	def new
		@post = Post.new
	end

	def show
		@post = Post.find(params[:id])
		@comment = Comment.new
		@comment.post_id = @post.id
		#redirect_to post_path(@comment.post)
	#	@coment.user = current_user.id
	end

	def create
  		@post = Post.new(post_params)
  		@post.save
  		redirect_to post_path(@post)
	end

	def edit
		@post = Post.find(params[:id])
	end

	def update
  		@post = Post.find(params[:id])
  		@post.update(post_params)
  		flash.notice = "Post '#{@post.title}' Updated!"
  		redirect_to post_path(@post)
	end

	def destroy
		@post = Post.find(params[:id])
		
		@post.destroy
		redirect_to posts_path
	end


end