Question

I’m trying to make use of both :only and :include options in to_xml call in a Rails app. Here’s the code:

current_user.to_xml(
  :include => :subscription,
  :only => [:email, :username]
)

The result of this is somthing like:

<?xml version="1.0" encoding="UTF-8"?>
<user>
  <username>cristi</username>
  <email>[e-mail]</email>
  <subscription>
  </subscription>
</user>

The problem is that subscription has more fields, which are not included. I assume its because of the :only option.

Is there a way to overcome this (show all fields in the subsscription element), without using :except as an option in to_xml ?

I am using Rails 3.

Answer 1

Yes, you can. It works perfectly for me.

>> u = User.first
>> puts u.to_xml(:only => %w( id name ))
<?xml version="1.0" encoding="UTF-8"?>
<user>
  <name>Simone Carletti</name>
  <id type="integer">1</id>
</user>

>> puts u.to_xml(:only => %w( id name ), :include => :domains)
<?xml version="1.0" encoding="UTF-8"?>
<user>
  <name>Simone Carletti</name>
  <id type="integer">1</id>
  <domains type="array">
    <domain>
      <name>...</name>
      <id type="integer">0</id>
    </domain>
    <domain>
      <name>...</name>
      <id type="integer">0</id>
    </domain>
  </domains>
</user>

Make sure the :subscription association is correct. If it’s a one-to-many association, you need to use the pluralized version :subscriptions.