Add the ability to create cars and refuels

app/assets/stylesheets/basic.css.scss

@@ -0,0 +1,22 @@
+/* This file is a Sass file (http://sass-lang.com/) which is very
+   similar to CSS3 but it is translated to CSS2 */
+
+#content {
+  width: 800px;
+  margin: 0 auto;
+  padding: 20px 10px;
+}
+
+table {
+  margin: 20px 0;
+  border-collapse: collapse;
+
+  td, th {
+    border: 1px solid #eee;
+    padding: 6px;
+  }
+
+  thead tr {
+    background-color: #ddd;
+  }
+}

app/assets/stylesheets/forms.css.scss

@@ -0,0 +1,52 @@
+form {
+  margin: 0 0 25px 0;
+  font-family: Helvetica;
+
+  fieldset {
+    padding: 10px;
+    border: 1px solid #f1f1f1;
+  }
+
+  legend {
+    padding: 0 8px;
+    font-size: 1.1em;
+    font-weight: bold;
+  }
+
+  label {
+    margin: 0;
+    padding: 0 0 3px 0;
+    font-size: .8em;
+    font-weight: bold;
+    display: block;
+  }
+
+  input, textarea {
+    margin: 0;
+    padding: 0;
+  }
+
+  input[type="text"],
+  input[type="email"],
+  input[type="url"],
+  input[type="password"],
+  textarea {
+    width: 450px;
+    height: 23px;
+    font-size: 16px;
+    border: 1px solid silver;
+  }
+
+  textarea {
+    resize: none;
+    font-size: 12px;
+    height: 130px;
+  }
+
+  input[type="submit"],
+  input[type="button"] {
+    margin: 10px 0 10px 30px;
+    padding: 4px;
+    font-size: 1.2em;
+  }
+}

app/controllers/cars_controller.rb

@@ -1,9 +1,59 @@
 class CarsController < ApplicationController
 
+  ##############################################################################
+  # The following class method tells Rails what formats we can respond
+  # with.  This is necessary to use the `respond_with` helper later.
+  respond_to(:html, :xml, :json)
+
   ##############################################################################
   # Load all cars for the current user.  Rails automatically renders
   # the app/views/cars/index.html.erb file.
   def index
     @cars = current_user.cars.order(:name)
+    respond_with(@cars)
+  end
+
+  ##############################################################################
+  # Normally, if a model had enough information to display on a
+  # dedicated page you would do so here in the show action.  Since a
+  # car only has a name it doesn't make much sense to show that by
+  # itself, so we'll just redirect to the index action.
+  def show
+    redirect_to(cars_path)
+  end
+
+  ##############################################################################
+  # Using `respond_with` below will automatically render
+  # app/views/cars/new.html.erb if the current request wants HTML, or
+  # it can render XML or JSON if that's what the request calls for.
+  def new
+    @car = current_user.cars.new
+    respond_with(@car)
+  end
+
+  ##############################################################################
+  def create
+    @car = current_user.cars.create(params[:car])
+    respond_with(@car)
+  end
+
+  ##############################################################################
+  def edit
+    @car = current_user.cars.find(params[:id])
+    respond_with(@car)
+  end
+
+  ##############################################################################
+  def update
+    @car = current_user.cars.find(params[:id])
+    @car.update_attributes(params[:car])
+    respond_with(@car)
+  end
+
+  ##############################################################################
+  def destroy
+    @car = current_user.cars.find(params[:id])
+    @car.destroy
+    respond_with(@car)
   end
 end

app/controllers/refuels_controller.rb

@@ -0,0 +1,68 @@
+class RefuelsController < ApplicationController
+
+  ##############################################################################
+  # Establish a filter that will run before any of the actions in this
+  # controller run.  Its job will be to create a `@car` instance
+  # variable that we can use to access refuel objects.  The
+  # `fetch_car` method can be found at the bottom of this file.
+  before_filter(:fetch_car)
+
+  ##############################################################################
+  # See the note in cars_controller.rb
+  respond_to(:html, :xml, :json)
+
+  ##############################################################################
+  def index
+    @refuels = @car.refuels.order('refueled_at DESC')
+    respond_with(@car, @refuels) # need @car because this is a nested resource 
+  end
+
+  ##############################################################################
+  def show
+    @refuel = @car.refuels.find(params[:id])
+    respond_with(@car, @refuel)
+  end
+
+  ##############################################################################
+  def new
+    @refuel = @car.refuels.new
+    respond_with(@car, @refuel)
+  end
+
+  ##############################################################################
+  def create
+    @refuel = @car.refuels.create(params[:refuel])
+    respond_with(@car, @refuel)
+  end
+
+  ##############################################################################
+  def edit
+    @refuel = @car.refuels.find(params[:id])
+    respond_with(@car, @refuel)
+  end
+
+  ##############################################################################
+  def update
+    @refuel = @car.refuels.find(params[:id])
+    @refuel.update_attributes(params[:refuel])
+    respond_with(@car, @refuel)
+  end
+
+  ##############################################################################
+  def destroy
+    @refuel = @car.refuels.find(params[:id])
+    @refuel.destroy
+    respond_with(@car, @refuel)
+  end
+
+  ##############################################################################
+  private
+
+  ##############################################################################
+  # Since this controller is a nested resource under the cars
+  # resource, all invocations will include a `:car_id` parameter to
+  # tell us which car we are working with.
+  def fetch_car
+    @car = current_user.cars.find(params[:car_id])
+  end
+end

app/helpers/refuels_helper.rb

@@ -0,0 +1,2 @@
+module RefuelsHelper
+end

app/models/refuel.rb

@@ -27,6 +27,12 @@ class Refuel < ActiveRecord::Base
   ##############################################################################
   belongs_to(:car) # refuel.car
 
+  ##############################################################################
+  # A scope is a way to give a name to database query so it can be
+  # accessed by other models, controllers, and views.  You can see
+  # this being used in app/views/cars/index.html.erb.
+  scope(:most_recent, order('refueled_at DESC').limit(1))
+
   ##############################################################################
   # This method is used to find a refuel that occurred just prior to
   # this one.  We'll use this later to calculate MPG and distance
@@ -42,6 +48,18 @@ def following
     car.refuels.where('refueled_at > ?', refueled_at).order('refueled_at').first
   end
 
+  ##############################################################################
+  def formatted_mpg
+    "%.2f" % [mpg || 0.0]
+  end
+
+  ##############################################################################
+  def cost_per_mile
+    if other = preceding
+      preceding.price / distance
+    end
+  end
+
   ##############################################################################
   private
 

app/views/cars/_form.html.erb

@@ -0,0 +1,17 @@
+<%= form_for(@car) do |form| %>
+  <fieldset>
+    <legend><%= @title %></legend>
+
+    <%# Error messages would go here %>
+
+    <p>
+      <%= form.label(:name) %>
+      <%= form.text_field(:name) %>
+    </p>
+
+    <p>
+      <%= button_to_function('Cancel', "window.location='#{cars_path}'") %>
+      <%= form.submit %>
+    </p>
+  </fieldset>
+<% end %>

app/views/cars/edit.html.erb

@@ -0,0 +1,2 @@
+<% @title = 'Edit Car' %>
+<%= render('form') %>

app/views/cars/index.html.erb

@@ -1,4 +1,5 @@
-<% @title = 'Cars' %>
+<% @title = 'Your Cars' %>
+<h1><%= @title %></h1>
 
 <% if @cars.empty? %>
   <p>
@@ -11,14 +12,32 @@
   <thead>
     <tr>
       <th>Name</th>
+      <th>Last MPG</th>
+      <th>Cost Per Mile</th>
+      <th></th>
+      <th></th>
+      <th></th>
     </tr>
   </thead>
 
   <tbody>
     <% @cars.each do |car| %>
+      <% refuel = car.refuels.most_recent.first %>
+
       <tr>
-        <td><%= car.name %></td>
+        <td><%= link_to(car.name, edit_car_path(car)) %></td>
+        <td><%= refuel && refuel.formatted_mpg %></td>
+        <td><%= refuel && refuel.cost_per_mile.try(:format) %></td>
+        <td><%= link_to('Refuel', new_car_refuel_path(car)) %></td>
+        <td><%= link_to('History', car_refuels_path(car)) %></td>
+        <td><%= link_to('Delete', car_path(car), :method => :delete, :confirm => 'Are you sure?') %></td>
       </tr>
     <% end %>
   </tbody>
 </table>
+
+<% if !@cars.empty? %>
+  <%= link_to('Create a new car', new_car_path) %><br/>
+<% end %>
+
+<%= link_to('Log out', logout_path) %>

app/views/cars/new.html.erb

@@ -0,0 +1,3 @@
+<% @title = 'New Car' %>
+<%# The following line renders app/views/cars/_form.html.erb %>
+<%= render('form') %>

app/views/layouts/application.html.erb

@@ -1,14 +1,16 @@
 <!DOCTYPE html>
 <html>
-<head>
-  <title>Example</title>
-  <%= stylesheet_link_tag    "application" %>
-  <%= javascript_include_tag "application" %>
-  <%= csrf_meta_tags %>
-</head>
-<body>
-
-<%= yield %>
-
-</body>
+  <head>
+    <title><%= @title %></title>
+    <%= stylesheet_link_tag    "application" %>
+    <%= javascript_include_tag "application" %>
+    <%= csrf_meta_tags %>
+  </head>
+  <body>
+    <div id="content">
+      <% if flash.notice %><div class="notice"><%= flash.notice %></div><% end %>
+      <% if flash.alert  %><div class="alert" ><%= flash.alert  %></div><% end %>
+      <%= yield %>
+    </div>
+  </body>
 </html>

app/views/refuels/_form.html.erb

@@ -0,0 +1,32 @@
+<%= form_for([@car, @refuel]) do |form| %>
+  <fieldset>
+    <legend><%= @title %></legend>
+
+    <%# Error messages would go here %>
+
+    <p>
+      <%= form.label(:refueled_at, 'Refuel Date') %>
+      <%= form.datetime_select(:refueled_at) %>
+    </p>
+
+    <p>
+      <%= form.label(:odometer, 'Current Odometer Reading') %>
+      <%= form.number_field(:odometer) %>
+    </p>
+
+    <p>
+      <%= form.label(:gallons, 'Number of Gallons for This Refuel') %>
+      <%= form.number_field(:gallons) %>
+    </p>
+
+    <p>
+      <%= form.label(:price, 'Total Cost of This Refuel') %>
+      <%= form.number_field(:price) %>
+    </p>
+
+    <p>
+      <%= button_to_function('Cancel', "window.location='#{cars_path}'") %>
+      <%= form.submit %>
+    </p>
+  </fieldset>
+<% end %>

app/views/refuels/edit.html.erb

@@ -0,0 +1,2 @@
+<% @title = 'Edit Refuel Record For Your ' + @car.name %>
+<%= render('form') %>