with_options demo

with_options_demo.rb

## Classic
accepts_nested_attributes_for :addresses, reject_if: :all_blank, allow_destroy: true
accepts_nested_attributes_for :client_detail, reject_if: :all_blank, allow_destroy: true

## with_options
with_options reject_if: :all_blank, allow_destroy: true do |u|
  u.accepts_nested_attributes_for :addresses
  u.accepts_nested_attributes_for :client_detail
end

## If the last arg is a hash, the options are merged into said hash
with_options presence: true do |u|
  u.validates :name
  u.validates :client_detail,     if: :client?
  u.validates :specialist_detail, if: :specialist?
end