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what did i learn today

In a project we built, we are using que for doing our background-jobs, and there is a very simple (but sufficient) and clean web-ui, called que-web, allowing us to monitor the status of the jobs online.

And normally, you just include it in your project by adding the gem, and then adding the following to your config/routes.rb :

require "que/web"
mount Que::Web => "/que"

But, this is completely open and unauthenticated. So we use devise, and it is really easy to limit a route to authenticated users:

require "que/web"
authenticate :user do 
  mount Que::Web => "/que"
end

At least this limits the accessability to logged in users. But we wanted it to be available only to admin-users. So I thought I had to resort to defining my own constraint-class, as follows

class CanSeeQueConstraint
  def matches?(request)
    # determine if current user is allowed to see que
  end
end

and in the routes write it as follows

require 'can_see_que_constraint'
mount Que::Web, at: '/que', constraints: CanSeeQueConstraint.new 

The problem was: how do I get to the current user, in a constraint class? So I took a peek at how the authenticate block in devise works, and apparently there is an easier option: the authenticate block takes a lambda, where you can test the currently authenticated user. Woah! Just what we need. So we wrote the following to only allow our adminstrators to see/manage our background jobs:

authenticate :user, lambda {|u| u.roles.include?("admin") } do
  mount Que::Web, at: 'que'
end
During the migration of a huge application from rails2 to rails3 I encountered a seriously baflling error. In almost every controller spec, i got the the following error: [ruby] Caught ActionController::RoutingError: No route matches {:controller=>"home"} [/ruby] This got me puzzling. If i ran a single controller-spec it worked, running the whole bunch failed (using rake spec or rspec spec/controllers/**/*_spec.rb). So I posted a question on stackoverflow and on the rspec-mailing-list. When googling, all related issues seemed to be caused by actual errors in config/routes.rb, but my application was working, it was generating all links correctly. It only failed when testing, and only when running the full suite. What i did to solve this, was actually compare the log-files of a single group of working controllers with the total set of controllers. And there it was: the routing table was erased by the first spec i ran. We have a base controller class where the shared behaviour for our API-controllers is placed. To test this controller we create, inside our spec, a new controller-class that derives from that baseclass and add a new route. In rails2 and rspec1 this spec looked as follows (simplified): [ruby] require 'spec_helper' class WsTestController < Ws::BaseController def index end end ActionController::Routing::Routes.draw do |map| map.connect ':controller/:action/:id' map.connect ':controller/:action/:id.:format' end describe WsTestController do context "without authentication" do it("asks for Basic authentication") { get :index response.status.should contain("401") } end context "with authentication" do # .. snipped the rest .. end end [/ruby] Now apparently what happens now, in rails3, is that instead of adding routes, the entire routing table is replaced by these routes. Whoops. So in effect, this was almost the only controller-spec that actually worked. When i disabled this spec, or more specifically the part where the routes are manhandled, all my controller and view specs worked again. So how do you fix this? How can you dynamically add routes in rails3 at runtime? Luckily google found the solution here. So my working spec for rails3/rspec2 looks as follows (and that doesn't interfere with my other specs) : [ruby] require 'spec_helper' class WsTestController < Ws::BaseController def index render :text => 'this worked' end end describe WsTestController do before(:each) do begin _routes = Dpplus::Application.routes _routes.disable_clear_and_finalize = true _routes.clear! Dpplus::Application.routes_reloader.paths.each{ |path| load(path) } _routes.draw do # here you can add any route you want get "ws_test/index" end ActiveSupport.on_load(:action_controller) { _routes.finalize! } ensure _routes.disable_clear_and_finalize = false end end context "without authentication" do it("asks for Basic authentication") { get :index response.status.should contain("401") response.header["WWW-Authenticate"].should contain('Basic') } end context "with authentication" do # ..snipped ... end end [/ruby] Hope this helps :)