Example RailsAdmin configuration with a nested resource.

image.rb

# app/models/image.rb

class Image < ActiveRecord::Base

  belongs_to :term

  def serializable_hash(options = nil)
    hash = super
    hash.delete_if { |k, v| v.blank? }
    hash.delete('filename')
    hash['file_path'] = self.filename.present? ? self.filename.url.split('/').last(2).join('/') : nil
    hash.except('created_at', 'updated_at')
  end
  
end

rails_admin.rb

# config/initializers/rails_admin.rb

RailsAdmin.config do |config|

  ### snip
  
  config.audit_with :history, 'User'
  
  ### snip

end

term.rb

# app/models/term.rb

class Term < ActiveRecord::Base

  has_many :images, :order => 'preferred DESC', :dependent => :destroy
  accepts_nested_attributes_for :images, :allow_destroy => true

  def serializable_hash(options = nil)
    hash = super
    hash['title'] ||= "#{self.note_2} #{self.note_1}"
    hash.delete('audio')
    hash['audio_path'] = self.audio.present? ? self.audio.url.split('/').last(2).join('/') : nil
    hash.except('slug', 'created_at', 'updated_at', 'audio_notes', 'image_notes', 'note_1', 'note_2')
  end

end

user.rb

# app/models/user.rb

class User < ActiveRecord::Base
  devise :database_authenticatable, 
         :recoverable, :rememberable, :trackable, :validatable
end