我遇到了某种 nil 错误；这告诉我它正在调用nil，'name'但它没有告诉我在哪里。
这是我的路线：
# Mobile api
map.namespace :mobile_api do |api|
api.resources :updates, :only => [ :index ]
api.resources :checkouts, :collection => { :reading_progress => :put }
end
我正在使用邮递员来调试 api 调用。
这是我用邮递员作为 Raw 发送的数据，JSON 作为PUTurl
发送的数据localhost:3000/mobile_api/checkouts/reading_progress：
{"title":"Awesome post!", "tags": ["blue", "jeans"] }
当我删除 JSON 数据并在没有数据的情况下发出请求时，它会传递给控制器。
class MobileApi::CheckoutsController < ApplicationController
def reading_progress
binding.pry
end
end
一旦我将任何数据添加到邮递员发送，我就会收到此错误：
|ruby-1.8.7-p371| ubuntu-francois in ~/sites/mds
± |old-state ✗| → ./script/server
=> Booting Mongrel
=> Rails 2.3.17 application starting on http://0.0.0.0:3000
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rubyzip2-2.0.2/lib/zip/version.rb:2: warning: already initialized constant VERSION
=> Call with -d to detach
=> Ctrl-C to shutdown server
SQL (0.1ms) SET NAMES 'utf8'
SQL (0.1ms) SET SQL_AUTO_IS_NULL=0
Error occurred while parsing request parameters.
Contents:
{"title":"Awesome post!", "tags": ["blue", "jeans"] }
/!\ FAILSAFE /!\ Mon Jul 15 17:26:37 +0200 2013
Status: 500 Internal Server Error
undefined method `name' for nil:NilClass
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activesupport-2.3.17/lib/active_support/whiny_nil.rb:52:in `method_missing'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activesupport-2.3.17/lib/active_support/xml_mini/rexml.rb:29:in `merge_element!'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activesupport-2.3.17/lib/active_support/xml_mini/rexml.rb:18:in `parse'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activesupport-2.3.17/lib/active_support/xml_mini.rb:12:in `__send__'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activesupport-2.3.17/lib/active_support/xml_mini.rb:12:in `parse'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activesupport-2.3.17/lib/active_support/core_ext/hash/conversions.rb:171:in `from_xml'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/actionpack-2.3.17/lib/action_controller/params_parser.rb:34:in `parse_formatted_parameters'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/actionpack-2.3.17/lib/action_controller/params_parser.rb:11:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/actionpack-2.3.17/lib/action_controller/session/abstract_store.rb:177:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activerecord-2.3.17/lib/active_record/query_cache.rb:29:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activerecord-2.3.17/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in `cache'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activerecord-2.3.17/lib/active_record/query_cache.rb:9:in `cache'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activerecord-2.3.17/lib/active_record/query_cache.rb:28:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/activerecord-2.3.17/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/actionpack-2.3.17/lib/action_controller/failsafe.rb:26:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/lock.rb:11:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/lock.rb:11:in `synchronize'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/lock.rb:11:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/actionpack-2.3.17/lib/action_controller/dispatcher.rb:114:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/actionpack-2.3.17/lib/action_controller/reloader.rb:34:in `run'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/actionpack-2.3.17/lib/action_controller/dispatcher.rb:108:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.17/lib/rails/rack/static.rb:31:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/urlmap.rb:47:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/urlmap.rb:41:in `each'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/urlmap.rb:41:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.17/lib/rails/rack/log_tailer.rb:17:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/content_length.rb:13:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/chunked.rb:15:in `call'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/handler/mongrel.rb:67:in `process'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:159:in `process_client'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:158:in `each'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:158:in `process_client'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `run'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `initialize'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `new'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:285:in `run'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `initialize'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `new'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/mongrel-1.1.5/lib/mongrel.rb:268:in `run'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rack-1.1.6/lib/rack/handler/mongrel.rb:38:in `run'
/home/francois/.rvm/gems/ruby-1.8.7-p371/gems/rails-2.3.17/lib/commands/server.rb:111
./script/server:3:in `require'
./script/server:3
希望你能帮忙。