Agile Web Development with Rails, Edition 5

12.3 Iteration G3: Downloading an eBook 12.1 Iteration G1: Capturing an Order

Demonstrate various respond_to/format options, as well as "through" relations and basic authentication.

Define a "who_bought" member action

edit app/controllers/products_controller.rb

  def who_bought

    @product = Product.find(params[:id])

    @latest_order = @product.orders.order(:updated_at).last

    if stale?(@latest_order)

      respond_to do |format|

        format.atom

      end

    end

  end

Define an Atom view (using the Atom builder)

edit app/views/products/who_bought.atom.builder

atom_feed do |feed|

  feed.title "Who bought #{@product.title}"

  feed.updated @latest_order.try(:updated_at) 

  @product.orders.each do |order|

    feed.entry(order) do |entry|

      entry.title "Order #{order.id}"

      entry.summary type: 'xhtml' do |xhtml|

        xhtml.p "Shipped to #{order.address}"

        xhtml.table do

          xhtml.tr do

            xhtml.th 'Product'

            xhtml.th 'Quantity'

            xhtml.th 'Total Price'

          end

          order.line_items.each do |item|

            xhtml.tr do

              xhtml.td item.product.title

              xhtml.td item.quantity

              xhtml.td number_to_currency item.total_price

            end

          end

          xhtml.tr do

            xhtml.th 'total', colspan: 2

            xhtml.th number_to_currency \

              order.line_items.map(&:total_price).sum

          end

        end

        xhtml.p "Paid by #{order.pay_type}"

      end

      entry.author do |author|

        author.name order.name

        author.email order.email

      end

    end

  end

end

Add "orders" to the Product class

edit app/models/product.rb

class Product < ApplicationRecord

  has_many :line_items

  has_many :orders, through: :line_items

  #...

end

Add to the routes

edit config/routes.rb

Fetch the Atom feed

curl --max-time 15 --silent --user dave:secret http://localhost:3000/products/2/who_bought.atom

<?xml version="1.0" encoding="UTF-8"?>

<feed xml:lang="en-US" xmlns="http://www.w3.org/2005/Atom">

  <id>tag:localhost,2005:/products/2/who_bought</id>

  <link rel="alternate" type="text/html" href="http://localhost:3000"/>

  <link rel="self" type="application/atom+xml" href="http://localhost:3000/products/2/who_bought.atom"/>

  <title>Who bought CoffeeScript</title>

  <updated>2016-03-07T14:42:45Z</updated>

  <entry>

    <id>tag:localhost,2005:Order/1</id>

    <published>2016-03-07T14:42:45Z</published>

    <updated>2016-03-07T14:42:45Z</updated>

    <link rel="alternate" type="text/html" href="http://localhost:3000/orders/1"/>

    <title>Order 1</title>

    <summary type="xhtml">

      <div xmlns="http://www.w3.org/1999/xhtml">

        <p>Shipped to 123 Main St</p>

        <table>

          <tr>

            <th>Product</th>

            <th>Quantity</th>

            <th>Total Price</th>

          </tr>

          <tr>

            <td>CoffeeScript</td>

            <td>1</td>

            <td>$36.00</td>

          </tr>

          <tr>

            <th colspan="2">total</th>

            <th>$36.00</th>

          </tr>

        </table>

        <p>Paid by Check</p>

      </div>

    </summary>

    <author>

      <name>Dave Thomas</name>

      <email>customer@example.com</email>

    </author>

  </entry>

</feed>

Look at the headers

curl --max-time 15 --silent --dump - --output /dev/null --user dave:secret http://localhost:3000/products/2/who_bought.atom

HTTP/1.1 200 OK

X-Frame-Options: SAMEORIGIN

X-XSS-Protection: 1; mode=block

X-Content-Type-Options: nosniff

ETag: W/"3bd6a7698e95ecce37f82e18bc63d336"

Last-Modified: Mon, 07 Mar 2016 14:42:45 GMT

Content-Type: application/atom+xml; charset=utf-8

Cache-Control: max-age=0, private, must-revalidate

X-Request-Id: 722807ee-da14-4e99-8774-84c8af7216f0

X-Runtime: 0.009286

Transfer-Encoding: chunked

curl --max-time 15 --silent --dump - --output /dev/null --user dave:secret http://localhost:3000/products/2/who_bought.atom -H 'If-None-Match: W/"3bd6a7698e95ecce37f82e18bc63d336"'

HTTP/1.1 304 Not Modified

X-Frame-Options: SAMEORIGIN

X-XSS-Protection: 1; mode=block

X-Content-Type-Options: nosniff

ETag: W/"3bd6a7698e95ecce37f82e18bc63d336"

Last-Modified: Mon, 07 Mar 2016 14:42:45 GMT

Cache-Control: max-age=0, private, must-revalidate

X-Request-Id: a8a810e2-64d4-4750-95aa-b7c532b60c71

X-Runtime: 0.003937

curl --max-time 15 --silent --dump - --output /dev/null --user dave:secret http://localhost:3000/products/2/who_bought.atom -H 'If-Modified-Since: Mon, 07 Mar 2016 14:42:45 GMT'

HTTP/1.1 304 Not Modified

X-Frame-Options: SAMEORIGIN

X-XSS-Protection: 1; mode=block

X-Content-Type-Options: nosniff

ETag: W/"3bd6a7698e95ecce37f82e18bc63d336"

Last-Modified: Mon, 07 Mar 2016 14:42:45 GMT

Cache-Control: max-age=0, private, must-revalidate

X-Request-Id: 5c4ebde3-7954-4206-8187-3920d4989059

X-Runtime: 0.009131

12.3 Iteration G3: Downloading an eBook 12.1 Iteration G1: Capturing an Order