I have an User model (ActiveRecord). It has many Addresses
(ActiveRecord) and one CreditCard (ActiveModel)
When I submit my nested form the CreditCard validations did not fire.
So… in my User model I added this so the credit card validations
would get called.
def before_validation
credit_card.valid? unless credit_card.nil?
return true
end
This worked great. the missing credit card fields were highlighted
and everything… except
@user.errors.full_messages only contained errors for the user and
addresses.
So I updated my before_validation call again
def before_validation
credit_card.valid? unless credit_card.nil?
credit_card.errors.each{|k,v|
errors[“credit_card.#{k}”] = v
}
return true
end
Now everything is cool except the ugly error messages that nested
forms give you.
I chop off the credit card and addresses prefix when displaying them
<% @user.errors.full_messages.each do |msg| %>
<%
message = msg.gsub(/Credit card /, '').capitalize
message = message.gsub(/Addresses /, '').capitalize
%>
<li><%= message %></li>
<% end %>
This seems like a lot of work and I suspect there is a 1 liner I’m
missing that will make this all automatic.
Something like this in my user model.
has_one_virtual :credit_card
Does such a thing exist? I hope so 
================== Code snippets ====================
==== User model ====
class User < ActiveRecord::Base
acts_as_authentic
has_many :addresses
accepts_nested_attributes_for :addresses
validates :credit_card, :presence => true
attr_accessor :email_confirmation, :credit_card
validates_confirmation_of :email, :message => “should match
confirmation”
def credit_card_attributes=(attributes)
self.credit_card = CreditCard.new(attributes)
end
def before_validation
credit_card.valid? unless credit_card.nil?
credit_card.errors.each{|k,v|
errors[“credit_card.#{k}”] = v
}
return true
end
end
==credit_card=================
class CreditCard
include ActiveModel::Validations
include ActiveModel::AttributeMethods
include ActiveModel::Callbacks
include ActiveModel::Conversion
extend ActiveModel::Naming
belongs_to :user
attr_accessor :card_type, :card_number, :card_verification,
:card_expires_on, :agree
validates :card_type, :presence => true
validates :card_number, :presence => true
validates :card_verification, :presence => true
validates :card_expires_on, :presence => true
validates :agree, :presence => true
def initialize(attributes = {})
expire_date = {}
attributes.each do |name, value|
if name.include?(‘card_expires_on’)
expire_date[name] = value
else
send("#{name}=", value)
end
end
# yeah, this is a total mess. Can ActiveModel handle this?
ymd = expire_date.map(&:last).map(&:to_i)
begin
send(“card_expires_on=”, Time.zone.local(ymd[2], ymd[1],1))
unless ymd[1].blank? || ymd[2].blank?
rescue
end
end
def persisted?
false
end
end