Rails 3.1 select can have object as value

Is it possibel to give select a complete Object as value.

Code:

Models app/models/pc.rb

class Pc < Device
  has_many :gendevs
  accepts_nested_attributes_for :gendevs, :reject_if => lambda { |a| a[:name].blank? },:allow_destroy => true
end   

app/models/gendev.rb

class Gendev < Device
  belongs_to :pc
end

(Gendevs are something like scanners, cardreaders etc). Given Gendevs are available in Database, I wanna have a nested select, giving me the attributes of an object.

View:

app/views/pcs/_form.html.erb

....
<% f.fields_for :gendevs do |gd开发者_JAVA技巧builder| %>
<%= gdbuilder.select :gendevs, @gendevs.map { |g| [g.name + '/' + g.kind,g] } %>
<% end %>

This is not working, so my question is, how can i do this. Is there a way to serialize the params of g, or how can i do this?

Use g.id instead of g.

<% f.fields_for :gendevs do |gdbuilder| %>
<%= gdbuilder.select :gendevs, @gendevs.collect { |g| [g.name + '/' + g.kind, g.id] } %>
<% end %>