Rails code sample with CouchDB database, INI config files and custom email validation

01_ini_files.rb

# rails initializer to load *.ini into Rails.application.config

Dir.glob(File.join Rails.root, "/config/**/*.ini").each do |file_name|
  config_name = File.basename(file_name, ".ini")
  Rails.application.config.send "#{config_name}=", IniFile.new(file_name).to_struct.send(Rails.env)
end

email_validator.rb

require 'resolv'
require 'mail'

class EmailValidator < ActiveModel::EachValidator

  def validate_each(record, attribute, value)
    
    email = Mail::Address.new(value) rescue nil
    return invalid(record, attribute) unless email.present?

    # verify domain and parsed email address
    return invalid(record, attribute) unless email.domain.present? and email.address == value

    # valid domain must have at least two dot_atom_text elements (domainname.tld)
    domain_tree = email.send :tree # mail gem does not expose the tree method
    return invalid(record, attribute) unless domain_tree.domain.dot_atom_text.elements.size >= 2
    
    # check if the email domain has MX records
    Resolv::DNS.open do |dns|
      mx_records = dns.getresources(email.domain, Resolv::DNS::Resource::IN::MX)
      return invalid(record, attribute) unless mx_records.present?
    end
    
  end

  private

  def invalid(record, attribute)
    record.errors[attribute] << I18n.t('errors.messages.invalid')
  end

end

ini_file.rb

require 'ostruct'
require 'stringio'

class IniFile

  def initialize(stream_or_path)
    @options = {}
    if stream_or_path.respond_to? :read
      read_from_stream(stream_or_path)
    else
      read_from_stream(StringIO.new(File.read(stream_or_path)))
    end  
  end

  def to_hash
    @options
  end
  alias_method :to_h, :to_hash

  def to_struct
    struct = OpenStruct.new
    @options.each do |section,values|
      struct.send("#{section}=", OpenStruct.new(values))
    end
    struct
  end

  private

  def read_from_stream(stream)
    section = :general
    while l = stream.gets
      l.strip!
      next if l.start_with? "#" or l.start_with? ";"
      if l.start_with? "[" and l.end_with? "]"
        section = l[1..-2].to_sym
        @options[section] ||= {}
      else
        key, val = l.split("=", 2)
        next if key.nil? or val.nil?
        key = key.strip.to_sym
        val.strip!
        if @options[section].has_key?(key)
          unless @options[section][key].is_a?(Array)
            @options[section][key] = [@options[section][key]]
          end
          @options[section][key] << val
        else
          @options[section][key] = val
        end
      end
    end
  end

end

if __FILE__ == $0
require 'test/unit'
require 'stringio'

INI_FILE = <<-INI
[example.com]
url=http://localhost:3000

[cluster.example.com]
url=http://localhost:3000
url=http://localhost:3001
url=http://localhost:3002
INI

class TestIniFile < Test::Unit::TestCase
  def setup
    @ini_file = IniFile.new(StringIO.new(INI_FILE))
    @hash = @ini_file.to_h
  end

  def test_parsing_sections_to_hash_keys
    assert_equal [:"example.com", :"cluster.example.com"], @hash.keys
  end

  def test_parsing_sections_to_hash_values
    assert_equal [
      {:url=>"http://localhost:3000"},
      {:url=>["http://localhost:3000", "http://localhost:3001", "http://localhost:3002"]}
    ], @hash.values
  end

  def test_parsing_multiple_values_to_array
    assert_equal [
      "http://localhost:3000",
      "http://localhost:3001",
      "http://localhost:3002"
    ], @hash[:"cluster.example.com"][:url]
  end
end


end

inventory_card.rb

class InventoryCard < CouchRest::Model::Base
  include TenantModel
  include ActiveModel::SerializerSupport
  include TranslatedModel
  include TranslatedParameterizedName

  belongs_to :warehouse, :class_name => "Warehouse", :foreign_key => "warehouse_id"
  belongs_to :supplier,  :class_name => "Supplier",  :foreign_key => "supplier_id"
  belongs_to :vat_rate,  :class_name => "VatRate",   :foreign_key => "vat_rate_id"

  collection_of :categories

  property   :sku, String
  translates :name
  translates :parameterized_name
  translates :description
  property   :active, TrueClass, :default => true
  # 
  # ... other property declarations ...
  #
   timestamps!

   design do
    view :by_tenant_id_and_locale_and_parameterized_name, {
       :map => "
          function(doc) {
             if (doc['type'] == 'InventoryCard' && doc.name_translations && doc.active) {
               for(locale in doc.name_translations) {
                 emit([
                   doc.tenant_id,
                   locale,
                   doc.parameterized_name_translations[locale]
                 ], 1)
               }
             }
           }
       ",
       :reduce => "
          function(keys, values, rereduce) {
            return sum(values);
          }
       "
     }
     
     # ... other view declarations ...
     
  end

  alias_method :to_param, :parameterized_name

end

inventory_cards_controller.rb

class Api::V1::InventoryCardsController < Api::V1::BaseController

  before_action :find_resource, :only => %w{ show update destroy upload_image destroy_image }
  
  # sets HTTP headers for current page, per page and count and also @per_page var
  set_pagination_headers :inventory_cards, 10, :only => %w{ index }

  def index
    @inventory_cards = current_tenant.inventory_cards
      .page(params[:page]).per(@per_page)
    respond_with @inventory_cards.to_a
  end

  def show
    respond_with @inventory_card
  end

  def create
    @inventory_card = InventoryCard.create(
      params[:inventory_card].merge(:user_id => current_user.id, :id => nil)
    )
    respond_with @inventory_card
  end

  def update
    @inventory_card.update_attributes params[:inventory_card]
    respond_with @inventory_card
  end

  def destroy
    respond_with @inventory_card.destroy
  end

  def upload_image
    @inventory_card.add_image(params[:image].tempfile)
    respond_with @inventory_card.images
  end

  def destroy_image
    @inventory_card.delete_image(params[:file_name])
    respond_with @inventory_card.images
  end

  private

  def find_resource
    @inventory_card = InventoryCard.secure_find!(params[:id])
  end

end