Easily retrieve a list of all Models in your Ruby on Rails application

active_record_model_discovery.rb

module ModelDiscovery
  def self.models_hash
    @active_record_classes ||= valid_active_record_classes.index_by do |model|
      model.table_name
    end
  end

  def self.model_file_names
    @model_file_names ||= Dir['app/models/*.rb'].map {|f|
      File.basename(f, '.*')
    }
  end

  def self.model_classes
    @model_classes ||= model_file_names.map {|f|
      f.camelize.constantize rescue nil
    }.compact
  end

  def self.valid_active_record_classes
    @valid_active_record_classes ||= (model_classes.delete_if do |model|
      !model.respond_to?(:table_exists?) || !model.table_exists?
    end - models_to_exclude)
  end

  def self.models_to_exclude
    []
  end
end

def self.all_models
  ModelDiscovery.models_hash
end