为什么current_page?当我在完全管理的资源上做这件事时，返回“无路由错误”

Question

我有以下路由:

  resources :profiles do
    member do
      patch :speed_rating
      patch :dribbling_rating
      patch :passing_rating
      patch :tackling_rating
      post :favorite
      post :unfavorite
    end
    collection do
      get :autocomplete
    end
  end

生成以下我感兴趣的路由:

# truncated for brevity
profiles_path  GET  /profiles(.:format)  profiles#index
profile_path  GET   /profiles/:id(.:format)  profiles#show

在我的application.html.erb中，我有这个:

    <% if current_page?(controller: "profiles", action: "show")%>
      <div id="page-wrapper" class="gray-bg">
    <% else %>
      <div id="page-wrapper" class="image-bg">
    <% end %>

当我去我的Profiles#Show工作正常，但当我去我的Profiles#Index(又名我的root_path)，我得到别的东西:

Started GET "/" for ::1 at 2016-11-07 16:52:01 -0500
  User Load (1.9ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users"."id" ASC LIMIT $2  [["id", 7], ["LIMIT", 1]]
Processing by ProfilesController#index as HTML
  Role Load (4.8ms)  SELECT "roles".* FROM "roles" INNER JOIN "users_roles" ON "roles"."id" = "users_roles"."role_id" WHERE "users_roles"."user_id" = $1 AND (((roles.name = 'admin') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)))  [["user_id", 7]]
  Role Load (12.9ms)  SELECT "roles".* FROM "roles" INNER JOIN "users_roles" ON "roles"."id" = "users_roles"."role_id" WHERE "users_roles"."user_id" = $1 AND (((roles.name = 'coach') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)))  [["user_id", 7]]
  Role Load (6.7ms)  SELECT "roles".* FROM "roles" INNER JOIN "users_roles" ON "roles"."id" = "users_roles"."role_id" WHERE "users_roles"."user_id" = $1 AND (((roles.name = 'player') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)))  [["user_id", 7]]
   (4.9ms)  SELECT COUNT(*) FROM "roles" INNER JOIN "users_roles" ON "roles"."id" = "users_roles"."role_id" WHERE "users_roles"."user_id" = $1 AND (((roles.name = 'admin') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)) OR ((roles.name = 'coach') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)))  [["user_id", 7]]
  CACHE (0.0ms)  SELECT "roles".* FROM "roles" INNER JOIN "users_roles" ON "roles"."id" = "users_roles"."role_id" WHERE "users_roles"."user_id" = $1 AND (((roles.name = 'player') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)))  [["user_id", 7]]
   (2.6ms)  SELECT COUNT(*) FROM "roles" INNER JOIN "users_roles" ON "roles"."id" = "users_roles"."role_id" WHERE "users_roles"."user_id" = $1 AND (((roles.name = 'coach') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)) OR ((roles.name = 'admin') AND (roles.resource_type IS NULL) AND (roles.resource_id IS NULL)))  [["user_id", 7]]
  Profile Search (23.5ms)  curl http://localhost:9200/profiles_development/_search?pretty -d '{"query":{"match_all":{}},"size":1000,"from":0,"timeout":"11s","_source":false}'
  Tournament Load (2.7ms)  SELECT  "tournaments".* FROM "tournaments" ORDER BY "tournaments"."id" ASC LIMIT $1  [["LIMIT", 1]]
  Rendering profiles/index.html.erb within layouts/application
  Profile Load (1.7ms)  SELECT "profiles".* FROM "profiles" WHERE "profiles"."id" IN (14, 22, 12, 21, 9, 5, 4, 15, 6, 7, 16, 18, 13, 23, 17)
Read fragment views//profiles/14-20161105042425134917/profiles/22-20161106175803133611/profiles/12-20161101225114614189/profiles/21-20161103035514173735/profiles/9-20161104221706306433/profiles/5-20161105043153971213/profiles/4-20161103035528589634/profiles/15-20161029013919242687/profiles/6-20161105043216951643/profiles/7-20161101001052922220/profiles/16-20161029020526832889/profiles/18-20161101223838805685/profiles/13-20161104221749051281/profiles/23-20161104062851335443/profiles/17-20161105043606243802/af785066fd895798884eea54748241db (0.1ms)
  Rendered profiles/index.html.erb within layouts/application (12.5ms)
Completed 500 Internal Server Error in 379ms (ActiveRecord: 36.4ms)

ActionController::UrlGenerationError - No route matches {:action=>"show", :controller=>"profiles"}:

编辑1

为记录，以下工作没有问题:

<% if (controller_name.eql? "profiles") && (action_name.eql? "show") %>

Answer 1

如果你看一下current_page?源代码，你会意识到它使用url_for，它实际上需要有效的选项来构建一个URL，并与你在地址栏看到的URL匹配。

如果没有:id, url_for(controller: "profiles", action: "show")将无法找到该路由。如果您尝试使用current_page?(controller: "profiles", action: "show", id: 1)，您将看到不会引发错误。

current_page不是此任务的最佳选择，因为它旨在测试完美匹配，包括其他查询字符串参数，如:

 # http://www.example.com/shop/checkout?order=desc&page=1
 current_page?(controller: 'shop', action: 'checkout', order: 'desc', page: '1')

在您的特殊情况下，您希望它匹配呈现show动作的任何页面。我认为您在Edit 1中提出的解决方案是合适的。如果您想要清理它，您可以将它封装在自己的helper中。