RoR link_to a different file - ruby-on-rails

Question

I made a file in my posts view called lists.html.erb, and it lists all the different posts. In my index.html.erb, it lists up to 5 posts. The button is supposed to link to multiple posts, but I get an error saying that I have an undefined local variable or method. I am trying:
<%= link_to "All Posts", lists_path %>
and
<%= link_to "All Posts", lists %>
For a question
Prefix Verb URI Pattern Controller#Action
new_user_session GET /users/sign_in(.:format) devise/sessions#new
user_session POST /users/sign_in(.:format) devise/sessions#create
destroy_user_session DELETE /users/sign_out(.:format) devise/sessions#destroy
user_password POST /users/password(.:format) devise/passwords#create
new_user_password GET /users/password/new(.:format) devise/passwords#new
edit_user_password GET /users/password/edit(.:format) devise/passwords#edit
PATCH /users/password(.:format) devise/passwords#update
PUT /users/password(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) devise/registrations#cancel
user_registration POST /users(.:format) devise/registrations#create
new_user_registration GET /users/sign_up(.:format) devise/registrations#new
edit_user_registration GET /users/edit(.:format) devise/registrations#edit
PATCH /users(.:format) devise/registrations#update
PUT /users(.:format) devise/registrations#update
DELETE /users(.:format) devise/registrations#destroy
posts GET /posts(.:format) posts#index
POST /posts(.:format) posts#create
new_post GET /posts/new(.:format) posts#new
edit_post GET /posts/:id/edit(.:format) posts#edit
post GET /posts/:id(.:format) posts#show
PATCH /posts/:id(.:format) posts#update
PUT /posts/:id(.:format) posts#update
DELETE /posts/:id(.:format) posts#destroy
root GET / posts#index
GET /*path(.:format) redirect(301, /)
Posts_controller.rb
class PostsController < ApplicationController
before_action :find_post, only: [:show, :edit, :update, :destroy]
def index
#posts = Post.all.order('created_at DESC')
end
def new
#post = Post.new
if #post.save
redirect_to #post
else
render 'new'
end
end
def create
#post = Post.new(post_params)
if #post.save
redirect_to #post, notice: "Post was saved"
else
render 'new', notice: "I could not save the post. Call me for help if it keeps happening"
end
end
def show
##post = Post.find(params[:id])
end
def edit
##post = Post.find(params[:id])
end
def lists
#posts = Post.all.order('created_at DESC')
end
def update
#post = Post.find(params[:id])
if #post.update(params[:post].permit(:title, :body))
redirect_to #post
else
render 'edit'
end
end
def destroy
##post = Post.find(params[:id])
if #post.destroy
redirect_to root_path
else
redirect_to post_path, notice: "I couldn't be deleted for some reason. Try again or contact me"
end
end
private
def post_params
params.require(:post).permit(:title, :body, :image, :slug)
end
def find_post
#post = Post.friendly.find(params[:id])
end
end

Answer 1

You have the method in your controller, but you didn't put the route for it:
def lists
#posts = Post.all.order('created_at DESC')
end
You can add a simple route, like
get 'lists' => 'posts#lists', :as => :lists
And if you run rake routes it will show this new route - lists_path so <%= link_to "All Posts", lists_path %> will work.