Ruby on rails - 在创建 session 并重定向主页后用户为零

Question

I am building a rails app.

• I am using devise to handle authentication
• If the user is an admin, he or she should be able to see a link in the navbar that redirects to the whole list of profiles (for testing purposes)

    <% if !user_signed_in? %>
        <li class="nav-item">
          <%= link_to "Sign up", new_user_registration_path, class: "nav-link" %>
        </li>
        <li class="nav-item">
          <%= link_to "Log in", new_user_session_path, class: "nav-link" %>
        </li>
      <% else %>
        <li class="nav-item">
          <%= link_to "Log out", destroy_user_session_path, method: :delete,  class: "nav-link" %>
        </li>
        <% if !@user.nil? && @user.admin? %>
          <li class="nav-item">
            <%= link_to "See all profiles", profiles_path, class: "nav-link" %>
          </li>
        <% end %>
        <li class="nav-item">
          <%= link_to "My profile", user_profile_path(current_user, current_user.user_profile), class: "nav-link" %>
        </li>
    <% end %>

• However, said link only shows after going inside the my profile link. I did a raise in the UserProfiles controller to see what's going on and apparently the user is nil in the homepage even after logging in, hence the reason why the see all profiles link is not appearing

• My guess is that I am missing an instance variable that provides the user id somewhere, (pages controller perhaps?) I don't have a users controller or user sessions controller yet. Basically, I don't understand why is the user nil after logging in and why is the log out link showing up without a user?

UserProfiles controller

class UserProfilesController < ApplicationController
  before_action :set_user, only: [:index, :show]
  
  def index
    @user_profiles = UserProfile.all
  end

  def show
    @user_profile = UserProfile.find(params[:id])
    @user_profile.user = @user
  end
  
  private
  
  def set_user
    @user = current_user
  end
end

Thanks for your help

Answer 1

You are not passing @user from the controller so cannot use in the view .

You should change your code to

<% if !@user_profile.user.nil? && @user_profile.user.admin? %>
   <li class="nav-item">
      <%= link_to "See all profiles", profiles_path, class: "nav-link" %>
    </li>
<% end %>