Rails slug for ancestry model

I have ancestry for my category model. Im using slug gem. Currently i have following:

class Category < ActiveRecord::Base
  slug :name
end


class CategoriesController < ApplicationController
  inherit_resources
  defaults :finder => :find_by_slug
  def show
    @category = Category.fin开发者_C百科d_by_slug(params['category_id'])
    show!
  end
end

  match "categories/:category_id" => 'categories#show', :as => :category

This works fine, but i want to show parent/children path instead of /children

if my category have parent. How to reach this?

For example i have BMW category and x5 as subcategory. I have now this links: /categories/bmw for bmw and /categories/x5 for x5. i need this link categories/bmw/x5 instead of subcategory

You can nest your matchstatement in your parent resource like this (in Rails 3 at least):

resources :things do
  match "categories/:category_id" => 'categories#show', :as => :category
end

This should create a route like /things/:thing_id/categories/:category_id

match "categories/:category_id" => 'categories#show', :as => :category_short
match "categories/:category/:category_id" => 'categories#show', :as => :category_long

  def category_path(category)
    unless category.is_root?
      category_long_path category.parent, category
    else
      category_short_path category
    end
  end