Vacuum

0 - Intro.md

Vacuum with Rails

Goal: Displaying products from the Amazon Product Advertising API.

Status:

WORKING

1 - main_controller.rb

class MainController < ApplicationController
  def index
    request = Vacuum.new('GB')
    
    request.configure(
      aws_access_key_id: '',
      aws_secret_access_key: '',
      associate_tag: ''
    )
    
    params = {
      'SearchIndex' => 'All',
      'Keywords'=> 'women',
      'ResponseGroup' => "ItemAttributes,Images"
    }

    raw_products = request.item_search(query: params)
    hashed_products = raw_products.to_h

    @products = []
    
    hashed_products['ItemSearchResponse']['Items']['Item'].each do |item|
      product = OpenStruct.new
      product.name = item['ItemAttributes']['Title']
      product.url = item['DetailPageURL']
      product.image_url = item['LargeImage']['URL']
      
      @products << product 
    end
  end
end

2 - index.html.erb

<h1>Products from the Amazon API</h1>
<% if @products.any? %>
  <% @products.each do |product| %>
    <div class="product">
      <%= link_to image_tag(product.image_url), product.url %>
      <%= link_to product.name, product.url %>
    </div>
  <% end %>
<% end %>

i don't think that porting it to asin will help you in any way. if you feel like spending some time on digging into it you can see a working demo here: http://asin.herokuapp.com/

Appreciate that @phoet, thanks a lot :)

@frankie-loves-jesus,

Would it be possible to tuck away Amazon API keys and values somewhere...

Build the request in a private method or, if you're so inclined, extract to a class.

To parse the response, you have a few options. If you just want to transform the hash to a Ruby-esque data container, throw it into Rash. Or write a small parser using Nokogiri or Ox. Latter will be more performant, if that matters.

If you ask me the controller is completely the wrong place for the API request stuff. Think about how you'd want to issue these API requests in you controller and then build the code to do just that. Like:

(consider this to be pseudo code. never ran. never tested.)

class MainController < ApplicationController
  def index
    ThirdPartyProducts.fetch 'Books', 'Ruby on Rails'
  end
end

class ThirdPartyProducts
  def self.fetch category, topic
    AmazonProducts.fetch(category, topic) + 
    SomeOtherStore.fetch(category, topic)
  end
end

class ThirdPartyProducts::AmazonProducts
  ACCESS_KEY_ID: 'ABCDEFGHIJKLMNOPQRST',
  SECRET_ACCESS_KEY: '<long messy key>',
  ASSOCIATE_TAG: 'lipsum-20'
  # or better yet, put these in environment variables
  # and read the using env['ACCESS_KEY_ID'] as
  # proposed in the vacuum Readme

  def self.fetch category, topic
    # all your product fetching logic here
  end
end

This is better because:

• Controllers aren't as easy to test as simple classes.
• Someone reading your controller code later just wants to know what you are doing in the controller action. Not how you are doing this. Try to keep the number of levels of abstractions within one method small. Again increases testability and readability.

Niko.