undefined method `remember_token=' for #<User:0x0000010b454f50> - ruby-on-rails-4

Question

I'm working through Rails Tutorial and am stuck in Ch 8 -- the bit about login sessions. The error appears when I submit an email/pw combination that should create a new session.
Here's the error:
NoMethodError in SessionsController#create
undefined method `remember_token=' for #<User:0x0000010b454f50>
Extracted source (around line #435):
else
match = match_attribute_method?(method.to_s)
match ? attribute_missing(match, *args, &block) : super
end
end
From there I look under create in the sessions controller. And I try to see where I call the remember_token method.
Sessions controller:
class SessionsController < ApplicationController
def new
end
def create
user = User.find_by(email: params[:session][:email].downcase)
if user && user.authenticate(params[:session][:password])
log_in user
#if 1 then remember, else forget
params[:session][:remember_me] == '1' ? remember(user) : forget(user)
remember user
redirect_to user
else
flash.now[:danger] = 'Invalid email/password combination'
render 'new'
end
end
def destroy
#call log_out helper method
log_out if logged_in?
redirect_to root_url
end
end
I call remember which looks important. Here's the session helper:
module SessionsHelper
#Logs in the given user.
def log_in(user)
session[:user_id] = user.id
end
def remember(user)
#generate a new token and provide the encrypted hash
user.remember
cookies.permanent.signed[:user_id]=user.id
cookies.permanent[:remember_token]=user.remember_token
end
def current_user
#if session user id exists, then set to user_id and then...
if (user_id = session[:user_id])
#set #current_user to the correct user account
#current_user||= User.find_by(id: user_id)
#else, if signed cookie user id exists, set to user_id and then...
elsif (user_id = cookies.signed[:user_id])
#set user to the correct user account and...
user = User.find_by(id: user_id)
#if user is authenticated, then log them in and set #current_user to user
if user && user.authenticated?(cookies[:remember_token])
log_in user
#current_user = user
end
end
end
def logged_in?
!current_user.nil?
end
#Forgets a persistent session
def forget(user)
user.forget
cookies.delete(:user_id)
cookies.delete(:remember_token)
end
def log_out
forget(current_user)
session.delete(:user_id)
#current_user = nil
end
end
That looks like the key -- cookies.permanent[:remember_token]=user.remember_token.
But I don't know how to define the remember_token method. When I go through the tutorial I don't see any methods that describe remember_token. The closest I get is in the user model (method called remember):
class User < ActiveRecord::Base
before_save { self.email = email.downcase }
belongs_to :courses
belongs_to :lessons
validates :first_name, presence: true, length: { maximum: 50 }
validates :last_name, presence: true, length: { maximum: 50 }
validates :email, presence: true, length: { maximum: 255 },
uniqueness: { case_sensitive: false }
has_secure_password
validates :password, length: { minimum: 6}
#Returns the hash digest of the given string
def User.digest(string)
cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
BCrypt::Password.create(string, cost: cost)
BCrypt::Password.create(string, cost: cost)
end
#Returns a random token
def User.new_token
SecureRandom.urlsafe_base64
end
#creates a new token (random string) then encypts it by returning a hash
def remember
self.remember_token = User.new_token
update_attribute(:remember_digest, User.digest(remember_token))
end
#Returns true if the given token matches the digest
def authenticated?(remember_token)
return false if remember_digest.nil?
BCrypt::Password.new(remember_digest).is_password?(remember_token)
end
#forgets a user
def forget
update_attribute(:remember_digest, nil)
end
end
Am I understanding the interplay between the session controller, session helper and the user model? Is the interplay not setup right - and that's throwing the error? I don't understand why it doesn't work...
Background:
The tutorial intentionally avoids putting the remember_token in the database, as a security feature. So that isn't the problem.

Answer 1

The problem was in the sessions controller -- I didn't understand the ternary operator and had repeated a bit of its functionality. Here's the original Create method:
def create
user = User.find_by(email: params[:session][:email].downcase)
if user && user.authenticate(params[:session][:password])
log_in user
#if 1 then remember, else forget
params[:session][:remember_me] == '1' ? remember(user) : forget(user)
remember user
redirect_to user
else
flash.now[:danger] = 'Invalid email/password combination'
render 'new'
end
end
This bit remember user is redundant.
The ternary params[:session][:remember_me] == '1' ? remember(user) : forget(user) means if params[:session][:remember_me] is 1, then remember(user) else forget(user).
By then calling remember user (which is the same as remember(user)) I was executing the same things twice, causing the error.