CODEWITHSUNDEEP
rubyruby-on-rails-3routessti
Ion the Geek
Ion the Geek

Reputation: 41

Single Table Inheritance and routing in Ruby on Rails 3.0

I am having some trouble getting routing to play nicely with Single Table Inheritance in my Ruby on Rails application. I am using Ruby 1.9.2 and Rails 3.0.6. This is in development so the back-end is SQLite3, in case that makes a difference.

Let's say I have two products, widgets and sprockets. My application keeps track of bug numbers and support case tickets for both the products but the bugs and support tickets themselves are stored in other systems. There are two separate teams that work on these two products.

I have implemented Single Table Inheritance for the two types of bug records because the validation rules for widget bug numbers and sprockets bug numbers are different (the two teams use different bug tracking systems) and there is a possibility that I will have to add further products to the application that behave wildly differently. Using STI gives me the flexibility to implement additional methods and properties as required.

The widgets team only cares about widgets information and the sprockets team only cares about sprockets information. There is a third team that needs to be able to view the information on both the widgets and the sprockets. The widgets team will access the application using the path /widgets and the sprockets team will access the application using the path /sprockets. I set this up in routes.rb using namespaces:

resources :bugs

namespace "widgets" do
  resources :bugs
end

namespace "sprockets" do
  resources :bugs
end

I have set up the following models which work as expected when I fire up irb and use WidgetBug.create() or SprocketBug.create():

bug.rb

class Bug < ActiveRecord::Base
end

widget_bug.rb

class WidgetBug < Bug
  # Some validation rules
end

sprocket_bug.rb

class SprocketBug < Bug
  # Some different validation rules
end

I used scaffolding to create the controller and the view for the bug object, then modified the controller to try to generalize it so it could be used with both widgets bugs and sprockets bugs. For example, the index method looks like this:

  def index
    # The scaffold code lists all bugs, which is not what we want
    # @bugs = Bug.all

    # Only return bugs of the subclass we're looking for
    @bugs = eval("#{params[:controller].classify}.all")

    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render :xml => @bugs }
    end
  end

I then used create() to populate the database with several bugs of each type. Unfortunately when I browse to /widgets/bugs, the bugs for both products appear. After some debugging, I determined that the classify call is returning Widgets::Bugs or Sprockets::Bugs, so when I call all on it, it appears to be running against the superclass instead of running against the subclass.

I've reviewed the routing documentation and done quite a bit of searching on Google but I'm still at a loss as to how I can change the routing or the controller to make this work correctly. Any help would be greatly appreciated.

Upvotes: 4

Views: 3960

Answers (1)

fl00r
fl00r

Reputation: 83680

Checkout this post: STI, one controller

Routes

resources :widgets, :controller => "bugs", :type => "Widget"
resources :sprockets, :controller => "bugs", :type => "Sprocket"
# And I don't know if you need this
resources :bugs, :type => "Bug"

Controller

def index
  @bugs = params[:type].constantize.all
end

UPD

namespace "widgets" do
  resources :bugs, :type => "Widget"
end

namespace "sprockets" do
  resources :bugs, :type => "Sprocket"
end

Upvotes: 5

Related Questions