Create Session in Rails 3.1 Hartl Tutorial - ruby-on-rails

Question

This question is admittedly long. So I appreciate any support from the rubytutorial community. I am in Chapter 9, attempting to create a session for a logged-in user.
I've done the tutorial already in < Rails 3.1. Since I am now using Rails 3.1, I headed on over to Chapter 13 and linked to the (very good) Railscasts (#270) on the subject. I was able to rewrite my user sign up pretty easily thanks to has_secure_password.
When I try to log in with a user in the database I see this in the console):
No route matches {:action=>"show", :controller=>"users"}
Seems like I need to create a route and it should work. But if that is the case, why can I go 'users/1' and the view appear? I am using the route user_path(#user), #user in my sessions and users controllers (below).
Here is what I did.
Pass a form to the Session controller new action (note: I use form_tag and not form_for)
<%= form_tag sessions_path do %>
<div class="field">
<%= label_tag :email %><br />
<%= text_field_tag :email, params[:email] %>
</div>
<div class="field">
<%= label_tag :password %><br />
<%= password_field_tag :password %>
</div>
<div class="actions">
<%= submit_tag "Sign In" %>
</div>
<% end %>
Then, create action in sessions_controller.rb
def create
#Assign object by email attribute
user = User.find_by_email(params[:email])
# User is present and has access, must be true otherwise nil object
if user && user.authenticate(params[:password])
session[:user_id] = user.id
RIGHT HERE IS THE PROBLEM
redirect_to user_path(#user), :notice => "Logged in!"
else
#Use flash.now on render not flash[]
flash.now.alert = "Invalid email or password"
render "new"
end
end
And finally Create action for users_controller.rb, which works fine.
def create
#user = User.new(params[:user])
if #user.save
flash[:success] = "Welcome to the Sample App!"
redirect_to #user
else
render "new"
#user.password.clear
#user.password_confirmation.clear
end
end
Leaving my User model:
attr_accessible :name, :email, :password, :password_confirmation
email_regex = /\A[\w+\-.]+#[a-z\d\-.]+\.[a-z]+\z/i
has_secure_password
Oh and here is my current routes.rb file
resources :users
resources :sessions, only: [:create, :new, :destroy]
root to: "pages#home"
match "/about", to: "pages#about"
match "/contact", to: "pages#contact"
match "/help", to: "pages#help"
match "/signup", to: "users#new"
match "/signin", to: "sessions#new"
match "/signout", to: "sessions#destroy"
And finally my output when I run rake routes:
users GET /users(.:format) {:action=>"index", :controller=>"users"}
POST /users(.:format) {:action=>"create", :controller=>"users"}
new_user GET /users/new(.:format) {:action=>"new", :controller=>"users"}
edit_user GET /users/:id/edit(.:format) {:action=>"edit", :controller=>"users"}
user GET /users/:id(.:format) {:action=>"show", :controller=>"users"}
PUT /users/:id(.:format) {:action=>"update", :controller=>"users"}
DELETE /users/:id(.:format) {:action=>"destroy", :controller=>"users"}
sessions POST /sessions(.:format) {:action=>"create", :controller=>"sessions"}
new_session GET /sessions/new(.:format) {:action=>"new", :controller=>"sessions"}
session DELETE /sessions/:id(.:format) {:action=>"destroy", :controller=>"sessions"}
root / {:controller=>"pages", :action=>"home"}
about /about(.:format) {:controller=>"pages", :action=>"about"}
contact /contact(.:format) {:controller=>"pages", :action=>"contact"}
help /help(.:format) {:controller=>"pages", :action=>"help"}
signup /signup(.:format) {:controller=>"users", :action=>"new"}
signin /signin(.:format) {:controller=>"sessions", :action=>"new"}
signout /signout(.:format) {:controller=>"sessions", :action=>"destroy"}

Answer 1

It's your redirect_to #user and/or user_path(#user) lines. They generate requests to /users/:id, which apparently isn't in your routes.rb.

Answer 2

#user is nil in your example - you're assigning to user. What rails is telling you in a not very helpful way is that it can't route to :controller => 'users', :action => 'show' without a user.