Undefined method `user_path' in form_for - ruby-on-rails

Question

I have User model and Role model.
class User < ActiveRecord::Base
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
has_one :role
def has_role?(role_name)
self.role == Role.where(name: role_name).first
end
def add_role(role_name)
role = Role.where(name: role_name).first
self.role = role unless role.blank?
end
end
class Role < ActiveRecord::Base
belongs_to :user
end
For now, my app have 2 user roles; Admin & Member.
What I'm trying to do now is, giving ability to the Admin to change the member's role (from Admin to Member OR from Member to Admin) using select tag.
I have this inside my views/users/_form.html.erb
<div class="col-md-4">
<%= form_for(#user) do |f| %>
<% if #user.errors.any? %>
<div id="error_explanation">
<p><%= pluralize(#user.errors.count, "error") %> prohibited this user from being saved:</p>
<ul>
<% #user.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="form-group">
<%= f.label :email %><br>
<%= f.text_field :email, class: "form-control" %>
<%= f.label :role %>
<%= f.select :role_id, options_for_select(Role.all.map{|c| [c.name, c.id]}, f.object.role_id)%>
</div>
<%= f.submit 'Save user', :class => 'btn btn-primary' %>
<%= link_to 'Back', users_path, class: "btn btn-primary" %>
<% end %>
</div>
This is my User controller:
class UsersController < ApplicationController
before_action :authenticate_user!
before_action :set_user, only: [:show, :edit, :update, :destroy]
# GET /users
# GET /users.json
def index
#users = User.all
end
# GET /users/1
# GET /users/1.json
def show
end
# GET /users/1/edit
def edit
end
# PATCH/PUT /users/1
# PATCH/PUT /users/1.json
def update
respond_to do |format|
if #user.update(user_params)
format.html { redirect_to users_path, notice: 'user was successfully updated.' }
format.json { render :show, status: :ok, location: #user }
else
format.html { render :edit }
format.json { render json: #user.errors, status: :unprocessable_entity }
end
end
end
# DELETE /users/1
# DELETE /users/1.json
def destroy
#user.destroy
respond_to do |format|
format.html { redirect_to users_url, notice: 'user was successfully destroyed.' }
format.json { head :no_content }
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_user
#user = User.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def user_params
params.require(:user).permit(:email, :encrypted_password)
end
end
And this is my routes.rb:
Rails.application.routes.draw do
devise_for :users
root "orders#index"
resources :orders
resources :drinks
resources :foods
# link to change foods/drinks status from 0 (processing) to 1 (done)
get '/orders/:id/update_foods_status', to: 'orders#update_foods_status', as: :update_foods_status
get '/orders/:id/update_drinks_status', to: 'orders#update_drinks_status', as: :update_drinks_status
# kitchen foods orders
get 'kitchen_foods', to: 'kitchen_foods#index'
# kitchen drinks orders
get 'kitchen_drinks', to: 'kitchen_drinks#index'
# list of all users
get 'users', to: 'users#index', as: :all_users
# single user
get 'users/:id', to: 'users#show', as: :single_user
# edit user
get 'users/:id/edit', to: 'users#edit', as: :edit_user
end
UPDATE: This is what I get after run rake routes
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
root GET / orders#index
orders GET /orders(.:format) orders#index
POST /orders(.:format) orders#create
new_order GET /orders/new(.:format) orders#new
edit_order GET /orders/:id/edit(.:format) orders#edit
order GET /orders/:id(.:format) orders#show
PATCH /orders/:id(.:format) orders#update
PUT /orders/:id(.:format) orders#update
DELETE /orders/:id(.:format) orders#destroy
drinks GET /drinks(.:format) drinks#index
POST /drinks(.:format) drinks#create
new_drink GET /drinks/new(.:format) drinks#new
edit_drink GET /drinks/:id/edit(.:format) drinks#edit
drink GET /drinks/:id(.:format) drinks#show
PATCH /drinks/:id(.:format) drinks#update
PUT /drinks/:id(.:format) drinks#update
DELETE /drinks/:id(.:format) drinks#destroy
foods GET /foods(.:format) foods#index
POST /foods(.:format) foods#create
new_food GET /foods/new(.:format) foods#new
edit_food GET /foods/:id/edit(.:format) foods#edit
food GET /foods/:id(.:format) foods#show
PATCH /foods/:id(.:format) foods#update
PUT /foods/:id(.:format) foods#update
DELETE /foods/:id(.:format) foods#destroy
update_foods_status GET /orders/:id/update_foods_status(.:format) orders#update_foods_status
update_drinks_status GET /orders/:id/update_drinks_status(.:format) orders#update_drinks_status
kitchen_foods GET /kitchen_foods(.:format) kitchen_foods#index
kitchen_drinks GET /kitchen_drinks(.:format) kitchen_drinks#index
all_users GET /users(.:format) users#index
single_user GET /users/:id(.:format) users#show
edit_user GET /users/:id/edit(.:format) users#edit
My problem:
When I navigate to /users/1/edit, I get this error:
NoMethodError in Users#edit
undefined method `user_path' for #<#<Class:0x007fb702901c88>:0x007fb70098aaf8>
How do I fix this problem?
I found this answer but I couldn't understand it very clearly. Would appreciate a better explaination and answer.
Note: I'm using Devise gem.

Answer 1

You have in your routes file:
devise_for :users
which adds:
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
Now what you want to do is allow admin to edit the users. For this you have defined:
# list of all users
get 'users', to: 'users#index', as: :all_users
# single user
get 'users/:id', to: 'users#show', as: :single_user
# edit user
get 'users/:id/edit', to: 'users#edit', as: :edit_user
which generates:
all_users GET /users(.:format) users#index
single_user GET /users/:id(.:format) users#show
edit_user GET /users/:id/edit(.:format) users#edit
Now in the form you are writing <%= form_for(#user) do |f| %> which by default is searching for user_path. So instead of the different routes you are defining just add:
resources :users
which will generate all the necessary routes you require and map the form to the correct path. This will save a lot of overhead like using only this <%= form_for(#user) do |f| %> will take you to the create action when the user is a new object and it will take you to the update action if the user is a persisted object.
Or if you need to user your routes then you need to do:
<%= form_for(#user, url: edit_user_path, method: :get) do |f| %>
But it always a bad idea to use GET method in form submission. These links might help you:
When should I use GET or POST method? What's the difference between them?
When do you use POST and when do you use GET?
Update:
As you need to assign a single role to the user from multiple it is better to use a select box like this:
f.collection_select(:role_id, Role.all, :id, :name)
Assuming that the user table has attribute role_id and the role table has attribute name. So this will allow you to assign a role to user. What you are printing is user.role which will always print the association instead of the role name.
Hope this helps.

Answer 2

Try using edit_user_path instead of user_path if you want to link to the edit page. If you take a look at your routes.rb file there is no route for user_path.