Example displaying eager loading with perpetuity-postgres for https://github.com/jgaskins/perpetuity-postgres/issues/18

customer_accounts.rb

require 'perpetuity/postgres'
require 'securerandom'
require 'pp'

Perpetuity.data_source 'postgres://localhost/customer_stuff'

module Customer
  class User
    attr_accessor :name, :email, :api_key, :accounts

    def initialize attributes={}
      @name = attributes[:name]
      @email = attributes[:email]
      @api_key = attributes[:api_key]
      @accounts = attributes.fetch(:accounts) { [] }
    end
  end

  class Account
    attr_accessor :oauth_token, :provider

    def initialize attributes={}
      @oauth_token = attributes[:oauth_token]
      @provider = attributes[:provider]
    end
  end
end

Perpetuity.generate_mapper_for Customer::User do
  attribute :name, type: String
  attribute :email, type: String
  attribute :api_key, type: String
  attribute :accounts
  index :api_key
end

Perpetuity.generate_mapper_for Customer::Account do
  attribute :oauth_token, type: String
  attribute :provider, type: String

  index :oauth_token
end

account = Customer::Account.new(oauth_token: SecureRandom.hex,
                                provider: 'linkedtwitface')

me = Customer::User.new(name: 'Jamie',
                        email: 'jgaskins@gmail.com',
                        api_key: SecureRandom.hex,
                        accounts: [account])

user_mapper = Perpetuity[Customer::User]

id = user_mapper.insert(me)

retrieved_user = user_mapper.find(id)
user_mapper.load_association! retrieved_user, :accounts

pp retrieved_user
# #<Customer::User:0x007f92f82ea788
#  @accounts=
#   [#<Customer::Account:0x007f92f82e8f28
#     @id="6a0c96d2-0f13-4daf-a946-695059384f29",
#     @oauth_token="e8650ccd5960a26cf0785d9a40273e36",
#     @provider="linkedtwitface">],
#  @api_key="e1fa7b308d610a33bb9bdba9c6f7373a",
#  @email="jgaskins@gmail.com",
#  @id="8186c56c-d5db-4c3d-85d0-39e9bd362fcf",
#  @name="Jamie">