I was wondering if anyone knew of a way to combine the new nested forms in rails 2.3 with a has_many through relationship via checkboxes. Basically I have a page model, a page_category model and a category_items join table. Pages have many page categories through category items. The category_items table is polymorphic so i can use it for other models who need categories (maybe this is overcomplicating everything though?). In a page''s edit form I want to be able to dynamically add new category fields and then associate the new ones I create and the other already created page categories to the current page via checkboxes. Hopefully this makes sense and can actually be done, I''d rather not have to go to another controller/form just to create and edit page categories. class Page < ActiveRecord::Base has_many :category_items, :as => :item, :dependent => :destroy has_many :page_categories, :through => :category_items, :source => :category, :source_type => "PageCategory", :uniq => true accepts_nested_attributes_for :page_categories, :allow_destroy => true, :reject_if => proc { |attrs| attrs.all? { |k, v| v.blank? } } end class PageCategory < ActiveRecord::Base has_many :pages, :through => :category_items, :source => :item, :source_type => ''Page'', :uniq => true end class CategoryItem < ActiveRecord::Base belongs_to :category, :polymorphic => true belongs_to :item, :polymorphic => true end Page Category partial for my page form (hooks into a jquery script to dynamically add/remove page category form fields)... <a href="#" id="page_categories" class="header">Categories<%hidden_field_tag "page[page_category_ids][]", "" %></a> <ul class="submenu"> <%- for category in PageCategory.all -%> <li> <%= check_box_tag "page[page_category_ids][]", category.id, @page.page_categories.include?(category), :class => "checkbox" %> <% f.fields_for category do |category_form| %><%category_form.text_field :title, :style => "width: 200px;", :class => "textfield small formElement" %><% end %> </li> <%- end -%> </ul> Right now, if I try and create or update a page I get the following error... ActiveRecord::UnknownAttributeError in Admin/pagesController#update unknown attribute: page_category RAILS_ROOT: /Users/rajo/Sites/boilerplate Application Trace | Framework Trace | Full Trace /Users/rajo/Sites/boilerplate/vendor/rails/activerecord/lib/ active_record/base.rb:2745:in `attributes='' /Users/rajo/Sites/boilerplate/vendor/rails/activerecord/lib/ active_record/base.rb:2741:in `each'' /Users/rajo/Sites/boilerplate/vendor/rails/activerecord/lib/ active_record/base.rb:2741:in `attributes='' /Users/rajo/Sites/boilerplate/vendor/rails/activerecord/lib/ active_record/base.rb:2627:in `update_attributes'' /Users/rajo/Sites/boilerplate/app/controllers/admin/ pages_controller.rb:107:in `update'' /Users/rajo/Sites/boilerplate/app/controllers/admin/ pages_controller.rb:106:in `update'' Request Parameters: {"commit"=>"Save", "_method"=>"put", "authenticity_token"=>"DvvJPsU9c942x1Ak5wOIm8V4wYv8AClftKJ7ohGqOo0=", "id"=>"about", "page"=>{"name"=>"About", "title"=>"About Us", "body"=>"<p>About this site.</p>", "published"=>"1", "page_category"=>{"title"=>"Default Two"}, "page_category_ids"=>["", "1", "2"], "home"=>"0"}} Show session dump Response Headers: {"Content-Type"=>"", "Cache-Control"=>"no-cache"} Thanks for any help in advance. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---