Structure based on friendly_id

index.html.erb

<h1>Places</h1>
<ul>
  <% @places.each do |place| %>
    <li><%= link_to place.name, [:new, place, :ticket] %></li>
  <% end %>
</ul>

===========================================================================

<h1><%= "New Ticket for %s" % @place.name %></h1>
<%= form_for [@place, @ticket] do |f| %>
  <p>
    <%= f.label :ticket_type_id %>
    <%= f.collection_select :ticket_type_id, TicketType.all, :id, :name %>
  </p>
  <p><%= f.submit %></p>
<% end %>

===========================================================================

<h1><%= 'Ticket #%d' % @ticket.id %></h1>
<p>Place: <b><%= @ticket.place_name %></b></p>
<p>Type: <b><%= @ticket.ticket_type_name %></b></p>

place.rb

class Place < ActiveRecord::Base
  has_many :tickets
  attr_accessible :name
  extend FriendlyId
  friendly_id :name, use: :slugged
end

places_controller.rb

class PlacesController < ApplicationController
  def index
    @places = Place.all
  end
end

rake_routes.sh

   place_tickets POST /places/:place_id/tickets(.:format)     tickets#create
new_place_ticket GET  /places/:place_id/tickets/new(.:format) tickets#new
          places GET  /places(.:format)                       places#index
          ticket GET  /tickets/:id(.:format)                  tickets#show
            root      /                                       places#index

routes.rb

Fabianoalmeida::Application.routes.draw do
  resources :places, only: [:index] do
    resources :tickets, only: [:new, :create]
  end
  resources :tickets, only: [:show]
  root :to => 'places#index'
end

schema.rb

ActiveRecord::Schema.define(:version => 20121206233226) do

  create_table "places", :force => true do |t|
    t.string   "name"
    t.string   "slug"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

  add_index "places", ["slug"], :name => "index_places_on_slug"

  create_table "ticket_types", :force => true do |t|
    t.string   "name"
    t.string   "slug"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

  add_index "ticket_types", ["slug"], :name => "index_ticket_types_on_slug"

  create_table "tickets", :force => true do |t|
    t.integer  "place_id"
    t.integer  "ticket_type_id"
    t.datetime "created_at",     :null => false
    t.datetime "updated_at",     :null => false
  end

  add_index "tickets", ["place_id"], :name => "index_tickets_on_place_id"
  add_index "tickets", ["ticket_type_id"], :name => "index_tickets_on_ticket_type_id"

end

spec.rb

require 'test_helper'

class PlacesControllerTest < ActionController::TestCase
  test "should get index" do
    get :index
    assert_response :success
    assert_not_nil assigns(:places)
  end
end

class TicketsControllerTest < ActionController::TestCase
  test "should get new with place" do
    get :new, place_id: places(:one)
    assert_response :success
    assert_not_nil assigns(:ticket)
    assert_equal places(:one), assigns(:ticket).place
  end

  test "should create with place" do
    post :create, place_id: places(:one), ticket: { ticket_type_id: ticket_types(:one) }
    assert_redirected_to assigns(:ticket)
    assert_equal places(:one), assigns(:ticket).place
  end

  test "should get show" do
    get :show, id: tickets(:one)
    assert_response :success
    assert_equal tickets(:one), assigns(:ticket)
  end
end

ticket.rb

class Ticket < ActiveRecord::Base
  belongs_to :place
  belongs_to :ticket_type
  attr_accessible :ticket_type_id
  delegate :name, to: :place, prefix: true
  delegate :name, to: :ticket_type, prefix: true
end

ticket_type.rb

class TicketType < ActiveRecord::Base
  has_many :tickets
  attr_accessible :name
  extend FriendlyId
  friendly_id :name, use: :slugged
end

tickets_controller.rb

class TicketsController < ApplicationController
  before_filter :find_place, only: [:new, :create]

  def new
    @ticket = @place.tickets.build
  end

  def create
    @ticket = @place.tickets.build(params[:ticket])
    if @ticket.save
      redirect_to @ticket, notice: "Successfully created ticket."
    else
      render action: "new"
    end
  end

  def show
    @ticket = Ticket.find(params[:id])
  end

  private

  def find_place
    @place = Place.find(params[:place_id])
  end
end