Question

I understand how to turn :controller, :action, :etc into a URL. I’m looking to do the reverse, how can the action that the rails router will call be found from the URL?

Answer 1

someone else might have a shorter way to do this, but if you are just evaluating a URL, then you go to the ActionController::Routing::RouteSet class

for a config.routes.rb

map.resources :sessions

the code to find is:

ActionController::Routing::Routes.recognize_path('/sessions/new', {:method => :get})
#=> {:controller => 'sessions', :action => 'new'}

Right:

ActionController::Routing::Routes.recognize_path('/sessions/1/edit', {:method => :get})
#=> {:controller => 'sessions', :action => 'edit', :id => 1}

Wrong – without the method being explicitly added, it will default match to /:controller/:action/:id:

ActionController::Routing::Routes.recognize_path('/sessions/1/edit')
#=> {:controller => 'sessions', :action => '1', :id => 'edit'}

If you are within the action and would like to know, it is quite a bit easier by calling params[:action]

everything you ever wanted to know about routeset can be found here: http://caboo.se/doc//classes/ActionController/Routing/RouteSet.html#M004878

Hope this helps!