_fixed.txt

OK, I figured it out. Dumb mistake: to create an optional format like
you see in `rake routes` as:
classify_user_asset GET    /users/:user_id/assets/:id/edit/
class(.:format) {:action=>"classify", :controller=>"assets"}

you would write:
map.with_options :controller => 'assets', :conditions => {:method
=> :get} do |assets|
  assets.classify_user_asset '/users/:user_id/assets/:id/edit/
class.:format', :action => 'classify'
end

I was writing:
map.with_options :controller => 'assets', :conditions => {:method
=> :get} do |assets|
  assets.classify_user_asset '/users/:user_id/assets/:id/edit/
class(.:format)', :action => 'classify'
end

because that is what I saw in `rake routes`.

Sorry for the n00b question, but I am glad I figured this out.

Yours,
trv 

assets_controller.rb

class AssetsController < ApplicationController
  #GET users/1/assets
  def index
    @new_asset = @user.assets.new
    @assets = @user.assets
  end

  # GET /users/1/assets/edit/class
  def edit_class    
  end
end

index.html.haml

#assets-to-process.yui-g
  - field_set_tag 'Assets to Process' do
    - @assets.each do |asset|
      = "My Asset"
      = link_to 'Classify', user_classify_asset_path(@user.id), :class => 'classify-button'

routes.rb

ActionController::Routing::Routes.draw do |map|
  # Map users and assets
  map.resources :users, :only => [:show, :edit, :update] do |users|
    users.resources :assets, :except => [:edit, :update]

    # This is splitting up the edit RESTful action into three parts: classify, metadatize, and route
    users.with_options :controller => 'assets', :conditions => {:method => :get} do |assets|
      assets.classify_asset   '/assets/:id/edit/class.:format',    :action => 'edit_class'
      assets.metadatize_asset '/assets/:id/edit/metadata.:format', :action => 'edit_metadata'
      assets.route_asset      '/assets/:id/edit/route.:format',    :action => 'edit_route'
    end
    
    # This is splitting up the update RESTful action into three parts: classify, metadatize, and route
    users.with_options :controller => 'assets', :conditions => {:method => :put} do |assets|
      assets.connect '/assets/:id/class.:format',    :action => 'update_class'
      assets.connect '/assets/:id/metadata.:format', :action => 'update_metadata'
      assets.connect '/assets/:id/route.:format',    :action => 'update_route'
    end
  end

  # Map login and logout
  map.resource  :user_session, :only => [:new, :create, :destroy]

  # Map the root url to the login page
  map.root :controller => "user_sessions", :action => "new", :conditions => {:method => :get}
end