Route alias, is it possible?

Question

I have a Vehicle model:

Routes:

map.resources :vehicles, :has_many => :suppliers

Everything works great, but Vehicle has a boolean attribute is_truck. I want to make an Alias so I can get the same resources filtering only trucks, I tried with:

Routes:

map.trucks '/trucks', :controller => :vehicles, :action => :index, :is_truck => true
map.trucks '/trucks/by_supplier/:supplier', :controller => :vehicles, :action => :index, :is_truck => true

The first one works well, but when I search within a Form the second doesn't work and searches all suppliers.

Controller:

class VehiclesController
   def index
     if params[:supplier]
       @vehicles = Vehicle.all :conditions => { :is_truck => params[:is_truck] }
     else
       @vehicles = Vehicle.all
     end
   end
   ...
end

Search Form:

<% form_for :truck, :url => {:controller => :trucks, :action => :index}, :html => {:method => :get} do |f| %>
  <% f.text_field :search %>
  <% f.submit 'Search Trucks' %>
<% end %>

Is it possible to map.resources as an alias ?

Answer 1

I found a cleaner way to do it, but Search is still broken under a specific supplier:

# Show all vehicles
map.connect '/vehicles/supplier/:supplier', :controller => :vehicles, :action => :index
map.resources :vehicles

# Only show trucks
map.connect '/trucks/supplier/:supplier', :controller => :vehicles, :action => :index, :is_truck => true
map.resources :vehicles, :as => 'trucks', :requirements => { :is_truck => true }

Resource: http://api.rubyonrails.org/classes/ActionController/Resources.html

Answer 2

Just amend your routes in the following way:

map.resources :vehicles, :has_many => :suppliers,
                         :collection => { :trucks => :get }

And check rake routes for the routes this generates. It will allow you to list vehicles which are trucks:

trucks_vehicles GET /vehicles/trucks(.:format)
                    {:controller=>"vehicles", :action=>"trucks"}

So you now just need to add a new action called "trucks" which works similar to "index". Forms should keep track on it's own (via form fields) if you create a truck or another vehicle. Don't try to trick around with rails routing, which usually would mean your app design is flawed which will get you into trouble later.

You may take a look at STI (single table inheritance: one table stores multiple classes of vehicles). Another way would be to create a trucks controller which inherits from the vehicles controllers and overwrites just some methods like so:

class TrucksController < VehiclesController
  def new
    @is_truck = true
    super
  end
  ...
end

or

class TrucksController < VehiclesController
  before_filter :this_is_a_truck
  ...

  private

  def this_is_a_truck
    @is_truck = true
    super
  end
end

Update: Here's another one (given you have a is_truck column):

class TrucksController < VehiclesController
  around_filter :with_truck_scope
  ...

  private

  # Scope every active record access with an is_truck condition
  # you may want to put this directly into the model to get rid of the .send
  # method and directly access "Vehicle.with_truck_scope &block" here
  def with_truck_scope(&block)
    Vehicle.send :with_scope, :find => { :conditions => "is_truck = 1" },
                              :create => { :is_truck => 1 }, &block
  end
end

But I recommend really first to try out going with the :collection and :member parameters of Rails' routing.