undefined method `errors' for nil:NilClass - Ruby on Rails - ruby-on-rails

Question

I am totally new in the Ruby on Rails. I have tried to show an message while register. Please check my controller and view code -
users_controller.rb
class UsersController < ApplicationController
#before_action :set_user, only: [:show, :edit, :update, :destroy, :success]
def login
render layout: false
end
def register
render layout: false
#user = User.new
end
def create_register
#user = User.new(create_user_params)
#raise #user.inspect
respond_to do |format|
if #user.save
format.html { redirect_to #users, notice: 'Registration was successfully created.' }
format.json { render :success, status: :created, location: #users }
else
format.html { render :register }
format.json { render json: #ruby_win_source.errors, status: :unprocessable_entity }
end
end
end
def success
raise #user.inspect
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(:name, :username, :email, :password, :image, :dob, :photo, :address)
end
end
register.html.erb
<%= form_tag(#user) do |f| %>
<% if #user.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#user.errors.count, "error") %> prohibited this user from being saved:</h2>
<ul>
<% #user.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
routes.rb
get 'register' => 'users#register'
post 'register' => 'users#create_register'
URL - http://localhost:3000/register
While I am loading this page I got this error message -
I searched in google and getting some same issue link. Follow step but my problem still not resolved. Please help me :(

Answer 1

The 2 lines in your register method are reversed. Try this:
def register
#user = User.new
render layout: false
end

Answer 2

In the create_register method you create a new user calling
#user = User.new(create_user_params)
but your strong params method is named user_params. Try changing the above line to
#user = User.new(user_params)

Answer 3

You are trying to run the method errors on a nil class. Very common issue when doing Rails. This line
<%= form_tag(#user) do |f| %>
<% if #user.errors.any? %>
is looking for a #user object. You did try to declare one here:
def register
render layout: false
#user = User.new
end
But based on the error I'm going to presume it failed. Not seeing a migration for the user table I'm guessing you didn't create one? To create a new User object for an active record class you need to run a migration against the database so that there is a table to work with.
http://guides.rubyonrails.org/active_record_migrations.html
I am also not seeing a model here. To user User.new you also need a model.
http://guides.rubyonrails.org/active_record_basics.html
Now there is one other tool that will making working in Rails much, much easier for you.
http://pryrepl.org/
Coolest tool ever. simply install the pry gem, require pry and place a newline with binding.pry wherever you need to pry into the code and you can play around directly with the code. For this instance I would do it like this.
def register
render layout: false
require `pry`; binding.pry;
#user = User.new
end
Then go to the terminal you are running your server and you are inside the code. Then try the failing part of the code. #user = User.new It will give you a much more illuminating error message.