NoMethodError in Users::Sessions#new

Question

I'm a new developer in ROR. I use devise authentication for sign_in or sign_up, it works very well, but when i select data(category or sub_category) from database in app/views/layouts/application.html.erb i get some errors as shown bellow:

NoMethodError in Users::Sessions#new

Showing C:/railsapp/facepro/app/views/layouts/application.html.erb where line #28 raised:

undefined method `each' for nil:NilClass

Extracted source (around line #28):    

 <% @categories.each do |category| %>
    <li><a href="#"><%= category.category_name %></a>
       <ul class="dropdown-menu">

please help me!

score 1 · Accepted Answer · answered Jul 21 '14 at 07:41

The accepted answer should not be accepted - it doesn't fix the core of the problem.

--

Devise

The core of your problem has nothing to do with Devise.

You clue is in the error itself:

Showing C:/railsapp/facepro/app/views/layouts/application.html.erb where line #28

Devise has absolutely no bearing on the application layout - it's only for user authentication. To fix this, you need to ensure you have the @categories variable defined every time you load the application layout

--

ApplicationController

To do this, you'll need to declare that variable each time you load a controller action. As every controller should inherit from the application controller, the way to do this is to use the before_action callback in your app/controllers/application_controller.rb file:

#app/controllers/application_controller.rb
Class ApplicationController < ActionController::Base
    before_action :set_categories

    private

    def set_categories
        @categories = Category.all
    end
end

score 0 · Answer 2 · answered Jul 21 '14 at 04:53

0

Going to guess that you haven't defined @categories in Sessions#new.

In SessionsController you will need something like this:

def new
  @categories = Category.all
  ...
end

answered Jul 21 '14 at 04:53

t56k

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when i create devise authentication it not create SessionsController .so in controller i create file sessions_controller.rb and add def new @categories = Category.all ... end but it still errors – Ma YongChhin Jul 21 '14 at 04:59
`SessionsController` comes with Devise. This might help you: http://stackoverflow.com/questions/13836139/rails-how-to-override-devise-sessionscontroller-to-perform-specific-tasks-when – t56k Jul 21 '14 at 05:03
@categories.each is called in your application.html.erb? – The Lazy Log Jul 21 '14 at 05:53
yes in my application.html.erb i'm select as shown bellow : <% @categories.each do |category| %>
<%= category.category_name %>

Ma YongChhin

Jul 21 '14 at 06:12

NoMethodError in Users::Sessions#new

2 Answers2