Question

Weird problem I’ve been stuck on for several hours now:

I’m writing a simple user login using Rails 3, where a user logs in with their email and password. In my User model, I’m trying to find the correct User object by their email, then continue to see if they’ve entered the correct password.

When I try to find the User from the rails console

>> User.find_by_email("[e-mail]")

I get the desired result – the correct User object is returned

  User Load (0.7ms)  SELECT `users`.* FROM `users` WHERE `users`.`email` = '[e-mail]' LIMIT 1  
=> #<User id: 21, first_name: "Test", last_name: "Man", hashed_password: "ca630762c6dce11af5a9923c7955131f8d6f7a16", cell_phone_number: nil, email: "[e-mail]", created_at: "2012-12-13 14:35:38", updated_at: "2012-12-13 14:35:38", salt: nil, is_admin: false>

But when I put the following piece of code in the model/user.rb file, I get a weird result

user = User.find_by_email("[e-mail]")
puts "******** user = #{user}"

Outputs the following:

******** user = #<User:0x10b7b82c8>

When I try to use this user variable, it errors out and says that the variable or method “user” is unknown

Here is the the output from the log file:

Started POST "/users/login_attempt" for 127.0.0.1 at Thu Dec 13 08:40:47 -0600 2012
                            Processing by UsersController#login_attempt as HTML
                              Parameters: {"password"=>"[FILTERED]", "utf8"=>"", "email"=>"asdf", "authenticity_token"=>"4xeLxpSb4GidsHUIe4b55LhOVJtDEiv5UaQYU9aBv5k=", "commit"=>"Log In"}
                              User Load (0.4ms)  SELECT `users`.* FROM `users` WHERE `users`.`email` = '[e-mail]' LIMIT 1

Here’s a few things that I’ve tried…

1. the the mysql query above definitely works. I’ve copied it into mysql and it got the correct user back.

2. I’ve tried find(id) which also doesn’t work. Returns a similar User:0x10b7b82c8

Overall, I can’t understand why the console would give a different result than the model code itself.

Any have any idea why I’m getting such a strange result returned from find_by?

Thanks a lot!

Edit: Here’s additional code since Frederick mentioned there wasn’t enough to find the problem.

From controllers/users_controller.rb

class UsersController < ApplicationController


  def login
  end

  def login_attempt

    authorized_user = User.authenticate(params[:email], params[:password])

      redirect_to({:controller => 'records', :action => 'list'} )

  end



  def new
@user = User.new
  end 

  def create
@user = User.new(params[:user])

    if @user.save
      redirect_to({:controller => 'records', :action => 'list'} )

    else
      render('new')
end

end



end

from models/user.rb

require 'digest/sha1'

class User < ActiveRecord::Base

attr_accessible :password, :password_confirmation, :email, :email_confirmation, :first_name, :last_name

attr_accessor :password


before_save :create_hashed_password
after_save :clear_password

# only on create, so other attributes of this user can be changed

#create method to authenticate login credentials
def self.authenticate(email,password)

  user = User.find_by_email("[e-mail]")

  puts "******** user = #{user}"

end

#method to check provided password against password stored in db

 def password_match?(password="")

     newuser.hashed_password == hash_password(password)

 end


#hash_password adds salt to password and encrypts it
def self.hash_password(password="")
    salted_pw = password + PW_SALT
    hashed_pw = Digest::SHA1.hexdigest(salted_pw)       
end

  private

  def create_hashed_password
    # Whenever :password has a value hashing is needed
    unless password.blank?
     # self.hashed_password = User.hash_password(password)
     self.hashed_password = User.hash_password(password)
    end
  end

  def clear_password
    # for security and b/c hashing is not needed
    self.password = nil
  end




end

Answer 1

A method returns the result of the last expression in it. In the case of your authenticate method that last expression is the call to puts, which always returns nil, so

authorized_user = User.authenticate(params[:email], params[:password])

is setting authorized_user to nil rather than the user retrieved from the database.