correct_user而不使用current_user？

Question

我希望沒有登錄的人能夠看到演示頁面。現在他們得到current_user的NoMethodError錯誤。

def show 
    @correct_user = current_user.challenges.find_by(id: params[:id]) 
end 

sessions_helper

# Returns the current logged-in user (if any). 
    def current_user 
    if (user_id = session[:user_id]) 
     @current_user ||= User.find_by(id: user_id) 
    elsif (user_id = cookies.signed[:user_id]) 
     user = User.find_by(id: user_id) 
     if user && user.authenticated?(:remember, cookies[:remember_token]) 
     log_in user 
     @current_user = user 
     end 
    end 
    end 

我使用@correct_user，因爲我只是想顯示某些東西來挑戰的創造者：

<% if @correct_user %> 
    # show stuff to user who made challenge 
<% else %> 
    # show to everyone else, which would mean logged in users and non logged in users 
<% end %> 

我怎樣才能讓非登錄用戶可以看到顯示頁面，除了在@correct_user之內？

Answer 1

if current_user 
    @correct_user = current_user.challenges.find_by(id: params[:id]) 
else 
    @correct_user = nil 
end 

Answer 2

很可能current_user更多的是返回nil，因此所面臨的挑戰的方法不能運行，讓您NoMethodError

Answer 3

上current_user如果current_user是null會導致你的錯誤調用.challenges。

def show 
    if current_user 
    @correct_user = current_user.challenges.find_by(id: params[:id]) 
    end 
end 

Answer 4

這應該有助於檢測current_user是否正確。

class UsersController < ApplicationController  
    before_action :set_challenge, only: :show 
    before_action :check_user, only: :show 

    private 

    def set_ challenge 
    @challenge = Challenge.find(params[:id]) 
    end 


    def check_user 
     if current_user.id != @challenge.user_id 
     redirect_to root_url, alert: "Sorry, You are not allowed to be here, Bye Bye))" 
     end 
    end 
end