has many through button

I'm working on three files to get a button working:

http://strawr.googlecode.com/svn/trunk/app/controllers/
categories_controller.rb

http://strawr.googlecode.com/svn/trunk/app/helpers/application_helper.rb

http://strawr.googlecode.com/svn/trunk/app/views/feeds/show.rhtml

so that when navigating to http://localhost:3000/feeds/show/2 there's a
drop down list of all Category objects (this works). I want to be able
to click on the "record" button so that it captures the feed_id, in this
case "2", and also the category_id from the drop-down list.

Currently clicking on this button as described will generate:

ActiveRecord::RecordNotFound in FeedsController#record

Couldn't find Feed without an ID

RAILS_ROOT: ./script/../config/..
Application Trace | Framework Trace | Full Trace

/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/active_record/
base.rb:1012:in `find_from_ids'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/active_record/
base.rb:419:in `find'
/home/thufir/Desktop/strawr/app/controllers/feeds_controller.rb:54:in
`record'

/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/active_record/
base.rb:1012:in `find_from_ids'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/active_record/
base.rb:419:in `find'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:1101:in `send'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:1101:in `perform_action_without_filters'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
filters.rb:696:in `call_filters'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
filters.rb:688:in `perform_action_without_benchmark'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
benchmarking.rb:66:in `perform_action_without_rescue'
/usr/lib/ruby/1.8/benchmark.rb:293:in `measure'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
benchmarking.rb:66:in `perform_action_without_rescue'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
rescue.rb:83:in `perform_action'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:435:in `send'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:435:in `process_without_filters'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
filters.rb:684:in `process_without_session_management_support'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
session_management.rb:114:in `process'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:334:in `process'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/dispatcher.rb:41:in `dispatch'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/webrick_server.rb:113:in
`handle_dispatch'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/webrick_server.rb:79:in
`service'
/usr/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
/usr/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
/usr/lib/ruby/1.8/webrick/server.rb:162:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
/usr/lib/ruby/1.8/webrick/server.rb:95:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:92:in `each'
/usr/lib/ruby/1.8/webrick/server.rb:92:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:23:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:82:in `start'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/webrick_server.rb:63:in
`dispatch'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/commands/servers/webrick.rb:59
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/
dependencies.rb:495:in `require'
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/
dependencies.rb:342:in `new_constants_in'
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/
dependencies.rb:495:in `require'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/commands/server.rb:39
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
script/server:3

/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/active_record/
base.rb:1012:in `find_from_ids'
/usr/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/active_record/
base.rb:419:in `find'
/home/thufir/Desktop/strawr/app/controllers/feeds_controller.rb:54:in
`record'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:1101:in `send'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:1101:in `perform_action_without_filters'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
filters.rb:696:in `call_filters'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
filters.rb:688:in `perform_action_without_benchmark'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
benchmarking.rb:66:in `perform_action_without_rescue'
/usr/lib/ruby/1.8/benchmark.rb:293:in `measure'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
benchmarking.rb:66:in `perform_action_without_rescue'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
rescue.rb:83:in `perform_action'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:435:in `send'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:435:in `process_without_filters'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
filters.rb:684:in `process_without_session_management_support'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
session_management.rb:114:in `process'
/usr/lib/ruby/gems/1.8/gems/actionpack-1.13.5/lib/action_controller/
base.rb:334:in `process'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/dispatcher.rb:41:in `dispatch'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/webrick_server.rb:113:in
`handle_dispatch'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/webrick_server.rb:79:in
`service'
/usr/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
/usr/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
/usr/lib/ruby/1.8/webrick/server.rb:162:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
/usr/lib/ruby/1.8/webrick/server.rb:95:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:92:in `each'
/usr/lib/ruby/1.8/webrick/server.rb:92:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:23:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:82:in `start'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/webrick_server.rb:63:in
`dispatch'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/commands/servers/webrick.rb:59
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/
dependencies.rb:495:in `require'
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/
dependencies.rb:342:in `new_constants_in'
/usr/lib/ruby/gems/1.8/gems/activesupport-1.4.4/lib/active_support/
dependencies.rb:495:in `require'
/usr/lib/ruby/gems/1.8/gems/rails-1.2.5/lib/commands/server.rb:39
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`gem_original_require'
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require'
script/server:3

Request

Parameters: None

Show session dump

Please ignore my previous post, I've gone in a totally different
direction.

While the follow tutorial is certainly dated, it's precisely what I want
to do:

"2. View
To allow our web visitors to relate an expense with many tags, we are
going to use multiple checkboxes. This is how it will look."
http://jrhicks.net/96

For my project, it's relating a feed with many tags; otherwise I'm aiming
for exactly what's described in the PDF of the above link.

So, I used svn to roll back a bit and start over. Here's where I'm at:

NoMethodError in Feeds#edit

Showing app/views/feeds/_form.rhtml where line #9 raised:

You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.each

Extracted source (around line #9):

http://strawr.googlecode.com/svn/trunk/app/views/feeds/_form.rhtml

Prior to editing _form.rhmtl the basic CRUD actions for the db were
vanilla, but worked.

thanks,

Thufir