amazon-ecs

amazon-ecs is a generic Ruby wrapper to access Amazon Product Advertising API.

The library wraps around Nokogiri element object. It provides an easy access to the XML response elements and attributes.

The gist is, if the API and the response schema are updated, amazon-ecs library will still work, and you only need to update the xml paths.

Installation

gem install amazon-ecs

Usage

require 'amazon/ecs'

# Default options:
#  options[:version] => "2013-08-01"
#  options[:service] => "AWSECommerceService"
Amazon::Ecs.configure do |options|
  options[:AWS_access_key_id] = '[your access key]'
  options[:AWS_secret_key] = '[you secret key]'
  options[:associate_tag] = '[your associate tag]'
end

# To replace default options
# Amazon::Ecs.options = { ... }

# To override default options
res = Amazon::Ecs.item_search('ruby', {:response_group => 'Medium', :sort => 'salesrank'})

# Search Amazon UK
res = Amazon::Ecs.item_search('ruby', :country => 'uk')

# Search all items, default search index: Books
res = Amazon::Ecs.item_search('ruby', :search_index => 'All')

res.is_valid_request?
res.has_error?
res.error                                 # error message
res.total_pages
res.total_results
res.item_page                             # current page no if :item_page option is provided

# Find elements matching 'Item' in response object
res.items.each do |item|
  # Retrieve string value using XML path
  item.get('ASIN')
  item.get('ItemAttributes/Title')

  # Return Amazon::Element instance
  item_attributes = item.get_element('ItemAttributes')
  item_attributes.get('Title')

  item_attributes.get_unescaped('Title') # unescape HTML entities
  item_attributes.get_array('Author')    # ['Author 1', 'Author 2', ...]
  item_attributes.get('Author')          # 'Author 1'

  # Return a hash object with the element names as the keys
  item.get_hash('SmallImage') # {:url => ..., :width => ..., :height => ...}

  # Return the first matching path
  item_height = item.get_element('ItemDimensions/Height')
  item_height.attributes['Units']        # 'hundredths-inches'

  # There are two ways to find elements:
  # 1) return an array of Amazon::Element
  reviews = item.get_elements('EditorialReview')
  reviews.each do |review|
    el.get('Content')
  end

  # 2) return Nokogiri::XML::NodeSet object or nil if not found
  reviews = item/'EditorialReview'
  reviews.each do |review|
    el = Amazon::Element.new(review)
    el.get('Content')
  end
end

Other Operations

# Item lookup
res = Amazon::Ecs.item_lookup("0974514055")
item = res.get_element("Item")

# Browse node lookup
res = Amazon::Ecs.browse_node_lookup("17")
nodes = res.get_elements("BrowseNode")
nodes.each do |node|
  node.get('Name')
end

# Similarity lookup
Amazon::ECS.similarity_lookup("0974514055")

# Other operation
Amazon::Ecs.send_request(:operation => '[OperationName]', :id => 123)

Refer to Amazon Product Advertising API documentation for more information on the operations and request parameters supported.

Dump and Load

res.marshal_dump         # xml string
res.marshal_load(xml)

Debug

Turn on the debug mode to display API request params, full URL and XML response:

Amazon::Ecs::debug = true

Or you could also set the DEBUG_AMAZON_ECS environment variable to 1.

DEBUG_AMAZON_ECS=1 [command]

License

[The MIT License]