event.rb

class Event < Ohm::Model

  reference :user, lambda { |id| User.find(id)}
  reference :item, lambda { |id| Item.find(id)}
  reference :transaction, lambda { |id|Transaction.find(id)}
  
  
  attribute :kind
  attribute :text
  attribute :created_at
  
  index :user_id
  index :item_id
  index :transaction_id
  index :created_at
  
  KINDS = %w[registration creation reception delivery]
  
  def validate
    assert_present :kind
    #KINDS = %w[registration creation reception delivery]
    assert KINDS.include?(self.kind), [:kind, :not_valid]
    #cheap before_create hook
    self.created_at = Time.now
  end
  

end