Question

所有。我正在关注carmen-rails文档，虽然我使用的是rails4，但在选择国家时我无法让州子区域工作。事实上，当离开子区域代码时，我甚至无法导航到该站点。我收到这个错误：

localhost:3000

Processing by OrdersController#new as HTML
  Rendered orders/_subregion_select.html.erb (1.9ms)
  Rendered orders/_form.html.erb (773.3ms)
  Rendered orders/new.html.erb within layouts/application (775.8ms)
Completed 500 Internal Server Error in 784ms

ActionView::Template::Error (undefined method `downcase' for nil:NilClass):
    1: <div id="order_state_wrapper">
    2:   <% parent_region ||= params[:parent_region] %>
    3:   <% country = Carmen::Country.coded(parent_region) %>
    4: 
    5:   <% if country.nil? %>
    6:     <em>Please select a country above</em>
  app/views/orders/_subregion_select.html.erb:3:in `_app_views_orders__subregion_select_html_erb__937058573181156642_69893053026600'
  app/views/orders/_form.html.erb:100:in `block in _app_views_orders__form_html_erb__3775537416523760398_69893046471120'
  app/views/orders/_form.html.erb:1:in `_app_views_orders__form_html_erb__3775537416523760398_69893046471120'
  app/views/orders/new.html.erb:6:in `_app_views_orders_new_html_erb__3931135682021831649_69893046299220'

看起来不像（国家，在这种情况下为“US”）参数从父区域传递，因为它是“nil”。有任何见解让这个工作（我假设使用rails4）？

应用程序/视图/命令/ _form.html.erb

<div class="control-group">
  <div class="field">
    <%= f.label :country, 'Country' %>
    <%= f.country_select :country, priority: %w(US CA), prompt: 'Please select a country' %>
  </div>
  <div class="field">
    <%= f.label :state %><br />
    <%= render partial: 'subregion_select', locals: {parent_region: f.object.country} %>
  </div>
</div>

应用程序/视图/命令/ _subregion_select.html.erb

<div id="order_state_wrapper">
  <% parent_region ||= params[:parent_region] %>
  <% country = Carmen::Country.coded(parent_region) %>
  <% if country.nil? %>
    <em>Please select a country above</em>
  <% elsif country.subregions? %>
    <%= subregion_select(:order, :state, parent_region) %>
  <% else %>
    <%= text_field(:order, :state) %>
  <% end %>
</div>

app / assets / javascripts / orders.js.coffee

# Place all the behaviors and hooks related to the matching controller here.
# All this logic will automatically be available in application.js.
# You can use CoffeeScript in this file: http://coffeescript.org/

$ ->
  $('select#order_country').change (event) ->
    select_wrapper = $('#order_state_wrapper')

    $('select', select_wrapper).attr('disabled', true)

    country = $(this).val()

    url = "/orders/subregion_options?parent_region=#{country}"
    select_wrapper.load(url)

config / routes.rb

get '/orders/subregion_options' => 'orders#subregion_options'

#rake routes

             Prefix      Verb   URI Pattern                          Controller#Action
orders_subregion_options GET    /orders/subregion_options(.:format)  orders#subregion_options

当直接浏览到子区域路线并指定国家/地区时：

http://localhost:3000/orders/subregion_options?parent_region=%22US%22

Started GET "/orders/subregion_options?parent_region=%22US%22" for 192.168.122.1 at 2013-07-08 13:20:21 -0400
Processing by OrdersController#subregion_options as HTML
  Parameters: {"parent_region"=>"\"US\""}
DEPRECATION WARNING: Relation#first with finder options is deprecated. Please build a scope and then call #first on it instead. (called from service at /usr/local/rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/webrick/httpserver.rb:138)
  User Load (0.2ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 1 ORDER BY "users"."id" ASC LIMIT 1
  Rendered orders/_subregion_select.html.erb (0.2ms)
Completed 200 OK in 4ms (Views: 1.3ms | ActiveRecord: 0.2ms)

Answer 1

gem carmen-rails未在http://ready4rails4.net/上注册，在其编写的github页面上

carmen-rails是一个Rails 3插件，它提供了两种新的表单帮助方法：country_select和subregion_select。

加上travis-ci.org https://travis-ci.org/jim/carmen-rails所有版本都使用rails 3.2完成。

我想说宝石可能不是Rails 4准备就绪。

您应该在github页面上打开一个问题。

在查看了你的评论后，我检查了你正在使用的分支，除了分支名称，我没有看到任何与Rails 4相关的提交。

看一下changelog文件（https://github.com/freerunningtechnologies/carmen-rails/blob/master/CHANGELOG.md）让我觉得rails 4的兼容性还没有完成，但也许我错了。

Answer 2

我在Rails 3.2.15应用程序上遇到了同样的错误。为了让它起作用，我不得不对卡门宝石进行一次小改动。按照这些说明你应该是金色的：

在项目根目录的终端中，使用bundle open carmen打开Carmen gem库。
找到文件lib/carmen/querying.rb。
将第15行替换为以下内容：

code = code.try(:downcase) # Codes are all ASCII

我已经向原作者提交了拉取请求，因此很快就会在主分支中修复，但在此之前您可以执行上述操作，或者您可以在gemfile中使用my fork，如下所示：

gem 'carmen', github: 'joshuapinter/carmen'

Answer 3

想出导致错误的事情我也跑了。

<div id="order_state_code_wrapper"> 
  <% parent_region ||= params[:parent_region] %>
  <% unless parent_region.nil? %>
     <% country = Carmen::Country.coded(parent_region) %>
  <% end%>
  <% if country.nil? %>
    <em>Please select a country above</em>
  <% elsif country.subregions? %>
    <%= subregion_select(:order, :state_code, parent_region) %>
  <% else %>
    <%= text_field(:order, :state_code) %>
  <% end %>
</div>

您需要添加此项以删除错误

 <% unless parent_region.nil? %>
     <% country = Carmen::Country.coded(parent_region) %>
  <% end%>

除非在页面加载时第一次使用parent_region是nil那个时间

并从网址和路由中移除 / orders ，因为它没有调用控制器操作subregion_options并使用subregion_options作为id

修改了网址和路由

 url = "/subregion_options?parent_region=#{country}"

 get '/subregion_options' => 'orders#subregion_options'

rails country选择状态子区域在rails4中

3 个答案: