module ActiveAdmin::ViewHelpers::DisplayHelper

def association_methods_for(resource) 

def association_methods_for(resource)
  return [] unless resource.class.respond_to? :reflect_on_all_associations
  resource.class.reflect_on_all_associations.map(&:name)
end

def display_name(resource)

See the setting in `application.rb` for the list of methods and their priority.
Attempts to call any known display name methods on the resource. 
def display_name(resource)
  render_in_context resource, display_name_method_for(resource) if resource
end

def display_name_method_for(resource)

If no methods are available and we're about to use the Kernel's `to_s`, provide our own.
To prevent conflicts, we exclude any methods that happen to be associations.
Looks up and caches the first available display name method. 
def display_name_method_for(resource)
  @@display_name_methods_cache ||= {}
  @@display_name_methods_cache[resource.class] ||= begin
    methods = active_admin_application.display_name_methods - association_methods_for(resource)
    method  = methods.detect{ |method| resource.respond_to? method }
    if method != :to_s || resource.method(method).source_location
      method
    else
      DISPLAY_NAME_FALLBACK
    end
  end
end

def pretty_format(object)

Attempts to create a human-readable string for any object 
def pretty_format(object)
  case object
  when String, Numeric, Arbre::Element
    object.to_s
  when Date, Time
    localize object, format: :long
  else
    if defined?(::ActiveRecord) && object.is_a?(ActiveRecord::Base) ||
       defined?(::Mongoid)      && object.class.include?(Mongoid::Document)
      auto_link object
    else
      display_name object
    end
  end
end