你可以这样做:

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

现在，你可以这样用:

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

要查找URI:

current_uri = request.env['PATH_INFO']
# If you are browsing http://example.com/my/test/path, 
# then above line will yield current_uri as "/my/test/path"

找到路径，即控制器，动作和参数:

path = ActionController::Routing::Routes.recognize_path "/your/path/here/"

# ...or newer Rails versions:
#
path = Rails.application.routes.recognize_path('/your/path/here')

controller = path[:controller]
action = path[:action]
# You will most certainly know that params are available in 'params' hash

你可以通过rake:routes看到所有的路由(这可能对你有帮助)。

我能在2015年提出的最简单的解决方案(使用Rails 4验证，但也应该使用Rails 3)

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

你可以这样做

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

它在rails 3.1.0.rc4中为我工作

或者更优雅地说:request.path_info

来源: 请求机架文档