Enumerator fun

event.rb

require "active_support/all"

class Event

  STATES = %w(active archived)

  def self.types(&block)
    return to_enum(__callee__) unless block

    types = {
      entity_address: [
        "verified_for_billing",
        "verified_for_care",
        "verified_for_records",
        "verified_for_serve"
      ],
      order: [
        "case_number_empty",
        "case_number_set"
      ]
    }

    types.each do |k, v|
      v.each do |t|
        yield k,t
      end
    end
  end

  def self.types_for(model)
    model = model.to_s.underscore.to_sym
    types.select { |k, t| k == model }
  end

  types.each do |model, type|
    define_singleton_method "#{model}_#{type}" do
      puts "events.event_type = ?", "#{model}.#{type}"
    end
  end

  attr_accessor :item_type

  def initialize(type=nil)
    @item_type = type
  end

  # Validation options for event type based on item type.
  def event_type_options
    event_types = self.class.types_for(item_type)
    event_types.map { |model, type| "#{model}.#{type}" }
  end

end


e = Event.new
puts e.event_type_options.inspect
# => []

e1 = Event.new("EntityAddress")
puts e1.event_type_options.inspect
# => ["entity_address.verified_for_billing", "entity_address.verified_for_care", "entity_address.verified_for_records", "entity_address.verified_for_serve"]

Event.entity_address_verified_for_billing
# => events.event_type = ?
# => entity_address.verified_for_billing

Event.order_case_number_empty
# => events.event_type = ?
# => order.case_number_empty

I like what you've done with self.types, certainly addresses the smell I had in my event_type_options.

Also, take a look at the Issue model in that project. It's a related example that used arrays to define the types and had a slightly cleaner options method than the Event model called for.

Will do.