[ruby-on-rails] How can I find out the current route in Rails?

I need to know the current route in a filter in Rails. How can I find out what it is?

I'm doing REST resources, and see no named routes.

I'll assume you mean the URI:

class BankController < ActionController::Base
  before_filter :pre_process 

  def index
    # do something
  end

  private
    def pre_process
      logger.debug("The URL" + request.url)
    end
end

As per your comment below, if you need the name of the controller, you can simply do this:

  private
    def pre_process
      self.controller_name        #  Will return "order"
      self.controller_class_name  # Will return "OrderController"
    end

You can do request.env['REQUEST_URI'] to see the full requested URI.. it will output something like below

http://localhost:3000/client/1/users/1?name=test

You can do this:

def active_action?(controller)
   'active' if controller.remove('/') == controller_name
end

Now, you can use like this:

<%= link_to users_path, class: "some-class #{active_action? users_path}" %>

Based on @AmNaN suggestion (more details):

class ApplicationController < ActionController::Base

 def current_controller?(names)
  names.include?(params[:controller]) unless params[:controller].blank? || false
 end

 helper_method :current_controller?

end

Now you can call it e.g. in a navigation layout for marking list items as active:

<ul class="nav nav-tabs">
  <li role="presentation" class="<%= current_controller?('items') ? 'active' : '' %>">
    <%= link_to user_items_path(current_user) do %>
      <i class="fa fa-cloud-upload"></i>
    <% end %>
  </li>
  <li role="presentation" class="<%= current_controller?('users') ? 'active' : '' %>">
    <%= link_to users_path do %>
      <i class="fa fa-newspaper-o"></i>
    <% end %>
  </li>
  <li role="presentation" class="<%= current_controller?('alerts') ? 'active' : '' %>">
    <%= link_to alerts_path do %>
      <i class="fa fa-bell-o"></i>
    <% end %>
  </li>
</ul>

For the users and alerts routes, current_page? would be enough:

 current_page?(users_path)
 current_page?(alerts_path)

But with nested routes and request for all actions of a controller (comparable with items), current_controller? was the better method for me:

 resources :users do 
  resources :items
 end

The first menu entry is that way active for the following routes:

   /users/x/items        #index
   /users/x/items/x      #show
   /users/x/items/new    #new
   /users/x/items/x/edit #edit

Simplest solution I can come up with in 2015 (verified using Rails 4, but should also work using Rails 3)

request.url
# => "http://localhost:3000/lists/7/items"
request.path
# => "/lists/7/items"

If you are trying to special case something in a view, you can use current_page? as in:

<% if current_page?(:controller => 'users', :action => 'index') %>

...or an action and id...

<% if current_page?(:controller => 'users', :action => 'show', :id => 1) %>

...or a named route...

<% if current_page?(users_path) %>

...and

<% if current_page?(user_path(1)) %>

Because current_page? requires both a controller and action, when I care about just the controller I make a current_controller? method in ApplicationController:

  def current_controller?(names)
    names.include?(current_controller)
  end

And use it like this:

<% if current_controller?('users') %>

...which also works with multiple controller names...

<% if current_controller?(['users', 'comments']) %>

In rails 3 you can access the Rack::Mount::RouteSet object via the Rails.application.routes object, then call recognize on it directly

route, match, params = Rails.application.routes.set.recognize(controller.request)

that gets the first (best) match, the following block form loops over the matching routes:

Rails.application.routes.set.recognize(controller.request) do |r, m, p|
  ... do something here ...
end

once you have the route, you can get the route name via route.name. If you need to get the route name for a particular URL, not the current request path, then you'll need to mock up a fake request object to pass down to rack, check out ActionController::Routing::Routes.recognize_path to see how they're doing it.

Should you also need the parameters:

current_fullpath = request.env['ORIGINAL_FULLPATH']
# If you are browsing http://example.com/my/test/path?param_n=N 
# then current_fullpath will point to "/my/test/path?param_n=N"

And remember you can always call <%= debug request.env %> in a view to see all the available options.

You can do this

Rails.application.routes.recognize_path "/your/path"

It works for me in rails 3.1.0.rc4

Or, more elegantly: request.path_info

Source:
Request Rack Documentation

You can see all routes via rake:routes (this might help you).

I find that the the approved answer, request.env['PATH_INFO'], works for getting the base URL, but this does not always contain the full path if you have nested routes. You can use request.env['HTTP_REFERER'] to get the full path and then see if it matches a given route:

request.env['HTTP_REFERER'].match?(my_cool_path)

request.url

request.path #to get path except the base url