rails + devise + cancancan + rolify - Unable to view user info in a User index view

Question

My objective is to have a User Admin menu option in the navbar that is enabled if the current user is an admin user. The admin user can select this and will be routed to the users_path which in rails routes is:

users GET /users(.:format) users#index

Within app/views/users/index.html.erb is a table which displays username and email currently. The end objective is to also have an admin checkbox so an admin user can check this against a user to change the role to 'admin' once submitted for that user. Basically a User Administration page to administer other users.

However, at the moment the table just has username and email fields in the table. The problem is that no data can be seen in this table. It is blank. BUT when I use debug I can see all the data in the debug panel when the page loads. user index page with table empty but debug panel populated with user data

Here is how it is currently setup:

1) routes.rb:

devise_for :users resources :users, only: [:index]

2) users_controller.rb

class UsersController < ApplicationController
  load_and_authorize_resource
  def index
    @users = User.all
  end
end

3) index.html.erb

<table id="user_list" class="display table table-striped table-sm table-hover" cellspacing="0" width="100%" >
  <thead>
     <tr>
       <th>Username</th>
       <th>Email</th>
      </tr>
   </thead>
   <tbody>
     <% @users.each do |user| %>
       <tr>
         <td><%= user.username%></td>
         <td><%= user.email %></td>
       </tr>
     <% end %>
   </tbody>
</table>

4) user model:

class User < ApplicationRecord
  rolify
  devise :database_authenticatable, :rememberable, :trackable, :registerable
  attr_accessor :username, :email, :password, :password_confirmation, :remember_me, :firstname, :lastname
  after_create :assign_default_role
  def assign_default_role
    self.add_role(:user) if self.roles.blank?
  end
end

5) application_controller.rb

class ApplicationController < ActionController::Base
  protect_from_forgery with: :exception
  before_action :authenticate_user!
  protected
  def configure_permitted_parameters
    added_attrs = %i[username email password password_confirmation remember_me]
    devise_parameter_sanitizer.permit :sign_in, keys: added_attrs
  end
end

6) cancan ability class

class Ability
  include CanCan::Ability
  def initialize(user)
    if user.has_role? :admin
      can :manage, :all
    else
      can :read, :all
    end
  end
end

Any ideas what is preventing the user data to display in the index.html.erb?

Try using the debugging tools pry or byebug to inspect the @users variable. What does @users.size give you for example? — max
@users.size returns 3, as there are three user rows in the db. I am using Rails debug helper and this pulls the data into the debug panel on the page. I just cant populate the username and email fields in the table with the corresponding data — wbanguna

wbanguna wbanguna · Accepted Answer · 2017-06-20T10:27:45

found the problem. I was using attr_accessor in the user model and strong parameters in the user_controller.

attr_accessor is deprecated and replaced by strong paramaters in Rails 4. You do not require both. After removing attr_accessor the data populated the table in the user index view.

rails + devise + cancancan + rolify - Unable to view user info in a User index view

1 Answers