Array show and edit Rails Admin

Create file config/initializers/rails_admin_pg_arrays.rb

Include this code

class RailsAdminPgArray < RailsAdmin::Config::Fields::Base
  register_instance_option :formatted_value do
    unless value.blank?
      value.join(',')
    end
  end
end

class RailsAdminPgStringArray < RailsAdminPgArray
  def parse_input(params)
    if params[name].is_a?(::String)
      params[name] = params[name].split(',')
    end
  end
end

class RailsAdminPgIntArray < RailsAdminPgArray
  def parse_input(params)
    if params[name].is_a?(::String)
      params[name] = params[name].split(',').collect{|x| x.to_i}
    end
  end
end

RailsAdmin::Config::Fields::Types::register(:pg_string_array, RailsAdminPgStringArray)
RailsAdmin::Config::Fields::Types::register(:pg_int_array, RailsAdminPgIntArray)


Configure de field in config/initializer/rails_admin.rb like this

config.model 'User' do |config|
    configure :emails, :pg_string_array
end