to_xml associations and :only

[Marcelo Barbudas]

Hi,

A call to to_xml(:only => [:field], :include => :association]) will
filter the association result too(the resulting association will only
have :field).

Is there a way around this?

I want to specify different filters for the main object and the
association.

--
M.

[Robert Zotter]

Marcelo

Unfortunately like you mentioned when you use the :only options it
will filter through all the associations as well. You can get around
this by passing a proc to_xml that appends the associations to the
builder. For example we will take the ever so popular example of a
User having many Posts.

class User
has_many :posts
end

class Post
belongs_to :user
end

user = User.first
posts = user.posts
post_proc = lambda do |options|
options[:builder] << posts.to_xml(:skip_instruct => true)
end

user.to_xml(:only => :first_name, :procs => post_proc)

Make sure you have the :skip_instruct => true option when you are
creating the xml for your associations so it does not add the XML
declaration <?xml version="1.0 ... >

Cheers.

--
Robert Zotter
Zapient, LLC
Ruby on Rails Development and Consulting

http://www.zapient.com
http://www.fromjavatoruby.com