ruby on rails -我应该如何使这个路由RESTful

出于RESTful的目的，我这样设置路由:

routes.rb

match 'shops/:sort/:genre/:area', :to => 'shops#index'  

但是如果genre是空的呢?它不会重定向到example.com/shops/newest_first//california吗?

如何解决这种路由和参数问题?谁能给我举个例子?

<

视图/strong>

<%= form_tag shops_path, :method => :get do %>
    <%= select_tag :sort, options_from_collection_for_select(Sort.all, 'id', 'name', params[:sort]), :prompt => "Newest first" %>
    <%= select_tag :genre, options_from_collection_for_select(Genre.all, 'id', 'name', params[:genre]), :prompt => "all" %>
    <%= select_tag :area, options_from_collection_for_select(Area.all, 'id', 'name', params[:area]), :prompt => "all" %>
<% end %>

另一个视图

def index
  if !params[:sort].blank?
    @shops = @shops.sort(params[:sort])
  end
  if !params[:area].blank?
    @shops = @shops.where(:area => params[:area])
  end
  .
  .
  .
end