Rails STI: ActiveRecord PUT transaction works, but fields don't update?

Question

I am creating an application using STI for the first time and I've stumbled onto a puzzling roadblock.

Given the following two models with inheritance:

User.rb
class User < ActiveRecord::Base
attr_accessible :email, :first_name, :last_name, #more follows


Waiter.rb
class Waiter < User

I made a form on /waiters/users/[:id]/edit that does the following:

<%= simple_form_for @user, 
      :url => { :controller => "admin/waiters/users", :action => "update"} do |f| %>
 <%= f.input :first_name %>
 <%= f.input :last_name %>
 <%= f.input :email %>
 <%= f.input :start_date %>
 <%= f.button :submit, "Save", class: "btn btn-primary"%>
<% end %>

However, pressing submit is putting a post request through but failing to update the actual data. Is it because there's still a wrong route? See the SQL dump below:

Started PUT "/admin/waiters/users/6" for 127.0.0.1 at 2013-02-10 20:45:59 -0800
Processing by Admin::Waiters::UsersController#update as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"6EB82/aWryLgj/tZcvoOWmw98PAPmJYUViAQronv6Fw=", "waiter"=>{"first_name"=>"John", "last_name"=>"Smith", "email"=>"[email protected]"}, "commit"=>"Save", "id"=>"6"}
  User Load (0.6ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 1 LIMIT 1
  Role Load (0.5ms)  SELECT "roles".* FROM "roles" INNER JOIN "user_roles" ON "roles"."id" = "user_roles"."role_id" WHERE "user_roles"."user_id" = 1
  Waiter Load (0.6ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 6 LIMIT 1
   (0.1ms)  BEGIN
  User Exists (0.4ms)  SELECT 1 AS one FROM "users" WHERE ("users"."email" = '[email protected]' AND "users"."id" != 6) LIMIT 1
  CACHE (0.0ms)  SELECT 1 AS one FROM "users" WHERE ("users"."email" = '[email protected]' AND "users"."id" != 6) LIMIT 1
   (2.4ms)  UPDATE "users" SET "perishable_token" = 'FplOAv6d4eOBv0gHW3b', "updated_at" = '2013-02-11 04:45:59.206797' WHERE "users"."id" = 6
   (0.7ms)  COMMIT
Redirected to http://localhost:3000/admin/waiters/users

The controller seems to be redirecting just fine after the update action, but the data isn't saved. What am I missing here? Appreciate the help for a Rails starter.

This is the Users Controller found in controllers/admin/waiters/

 def edit
    form_info
    @user = Waiter.find(params[:id])
  end

  def update
    @user = Waiter.find_by_id(params[:id])
    if @user.update_attributes(params[:user])
      flash[:notice] = "Successfully assigned Waiter."
      redirect_to admin_waiters_users_url()
    else
      form_info
      render :action => 'edit'
    end
  end

Answer 1

The problem is that you are pulling the wrong values from the params hash. Look at the logs:

Parameters: {"utf8"=>"✓", "authenticity_token"=>"6EB82/aWryLgj/tZcvoOWmw98PAPmJYUViAQronv6Fw=", "waiter"=>{"first_name"=>"John", "last_name"=>"Smith", "email"=>"[email protected]"}, "commit"=>"Save", "id"=>"6"}

The updated attributes are hashed through the waiter key. Now look at your update code:

if @user.update_attributes(params[:user])

You are getting params[:user]. Since you are using STI, I assume you want to keep params[:user], so you need to change your form code for the waiter. You should do:

<%= simple_form_for @user, as: :user,
      :url => { :controller => "admin/waiters/users", :action => "update"} do |f| %>