使用Rails 3和REST API的ActiveResource时出错(Error using ActiveResource with Rails 3 and REST API)

我有一个REST API，我试图使用Rails 3.0.1访问，返回：

<Sessions> <Session> <Title>This is a sample title</Title> ...Misc </Session> <Session> <Title>Another Title</Title> ...Misc </Session> </Sessions>

我已经设置了我的session.rb类：

class Session < ActiveResource::Base self.site = "http://example.com/rest" end

将返回XML的网址是http://example.com/rest/sessions 。

然后我有一个控制器，定义如下：

class HomeController < ApplicationController def index Session.all end end

我的观点index.html.erb定义如下：

<h1>List Sessions</h1> <% @sessions.each do |session| %> <div><%= session.title %></div> <% end %>

当我尝试查看此页面时，出现以下错误：

HomeController #index中的NoMethodError

undefined method `collect!' for #<Hash:0x00000105178af8>

可能导致此问题的原因是什么？ 我可以很好地访问网址（甚至使用http://example.com/rest/sessions.xml ）。 有没有办法调试ActiveResource来查看里面发生了什么？

编辑

这是堆栈跟踪：

activeresource (3.0.1) lib/active_resource/base.rb:885:in `instantiate_collection' activeresource (3.0.1) lib/active_resource/base.rb:857:in `find_every' activeresource (3.0.1) lib/active_resource/base.rb:777:in `find' activeresource (3.0.1) lib/active_resource/base.rb:803:in `all' app/controllers/home_controller.rb:4:in `index' actionpack (3.0.1) lib/action_controller/metal/implicit_render.rb:4:in `send_action' actionpack (3.0.1) lib/abstract_controller/base.rb:150:in `process_action' actionpack (3.0.1) lib/action_controller/metal/rendering.rb:11:in `process_action' actionpack (3.0.1) lib/abstract_controller/callbacks.rb:18:in `block in process_action' activesupport (3.0.1) lib/active_support/callbacks.rb:435:in `_run__140584718597918073__process_action__4423897468290757938__callbacks' activesupport (3.0.1) lib/active_support/callbacks.rb:409:in `_run_process_action_callbacks' activesupport (3.0.1) lib/active_support/callbacks.rb:93:in `run_callbacks' actionpack (3.0.1) lib/abstract_controller/callbacks.rb:17:in `process_action' actionpack (3.0.1) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' activesupport (3.0.1) lib/active_support/notifications.rb:52:in `block in instrument' activesupport (3.0.1) lib/active_support/notifications/instrumenter.rb:21:in `instrument' activesupport (3.0.1) lib/active_support/notifications.rb:52:in `instrument' actionpack (3.0.1) lib/action_controller/metal/instrumentation.rb:29:in `process_action' actionpack (3.0.1) lib/action_controller/metal/rescue.rb:17:in `process_action' actionpack (3.0.1) lib/abstract_controller/base.rb:119:in `process' actionpack (3.0.1) lib/abstract_controller/rendering.rb:40:in `process' actionpack (3.0.1) lib/action_controller/metal.rb:133:in `dispatch' actionpack (3.0.1) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' actionpack (3.0.1) lib/action_controller/metal.rb:173:in `block in action' actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:62:in `call' actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:62:in `dispatch' actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:27:in `call' rack-mount (0.6.13) lib/rack/mount/route_set.rb:148:in `block in call' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:93:in `block in recognize' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:68:in `optimized_each' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:92:in `recognize' rack-mount (0.6.13) lib/rack/mount/route_set.rb:139:in `call' actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:492:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/head.rb:14:in `call' rack (1.2.1) lib/rack/methodoverride.rb:24:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/params_parser.rb:21:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/flash.rb:182:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/session/abstract_store.rb:149:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/cookies.rb:287:in `call' activerecord (3.0.1) lib/active_record/query_cache.rb:32:in `block in call' activerecord (3.0.1) lib/active_record/connection_adapters/abstract/query_cache.rb:28:in `cache' activerecord (3.0.1) lib/active_record/query_cache.rb:12:in `cache' activerecord (3.0.1) lib/active_record/query_cache.rb:31:in `call' activerecord (3.0.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:355:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/callbacks.rb:46:in `block in call' activesupport (3.0.1) lib/active_support/callbacks.rb:415:in `_run_call_callbacks' actionpack (3.0.1) lib/action_dispatch/middleware/callbacks.rb:44:in `call' rack (1.2.1) lib/rack/sendfile.rb:107:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/remote_ip.rb:48:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/show_exceptions.rb:46:in `call' railties (3.0.1) lib/rails/rack/logger.rb:13:in `call' rack (1.2.1) lib/rack/runtime.rb:17:in `call' activesupport (3.0.1) lib/active_support/cache/strategy/local_cache.rb:72:in `call' rack (1.2.1) lib/rack/lock.rb:11:in `block in call' <internal:prelude>:10:in `synchronize' rack (1.2.1) lib/rack/lock.rb:11:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/static.rb:30:in `call' railties (3.0.1) lib/rails/application.rb:168:in `call' railties (3.0.1) lib/rails/application.rb:77:in `method_missing' railties (3.0.1) lib/rails/rack/log_tailer.rb:14:in `call' rack (1.2.1) lib/rack/content_length.rb:13:in `call' rack (1.2.1) lib/rack/handler/webrick.rb:52:in `service' /Users/swright/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service' /Users/swright/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run' /Users/swright/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/server.rb:183:in `block in start_thread'

I have a REST API that I am trying to access using Rails 3.0.1 that returns:

<Sessions> <Session> <Title>This is a sample title</Title> ...Misc </Session> <Session> <Title>Another Title</Title> ...Misc </Session> </Sessions>

I have set up my session.rb class defined:

class Session < ActiveResource::Base self.site = "http://example.com/rest" end

The url that will return the XML is http://example.com/rest/sessions.

I then have a controller that is defined as this:

class HomeController < ApplicationController def index Session.all end end

and my view, index.html.erb, is defined:

<h1>List Sessions</h1> <% @sessions.each do |session| %> <div><%= session.title %></div> <% end %>

When I try to view this page, I get the following error:

NoMethodError in HomeController#index

undefined method `collect!' for #<Hash:0x00000105178af8>

What could be causing this issue? I can access the url just fine (even using http://example.com/rest/sessions.xml). Is there a way to debug ActiveResource to see what is happening inside?

EDIT

Here is the stack trace:

activeresource (3.0.1) lib/active_resource/base.rb:885:in `instantiate_collection' activeresource (3.0.1) lib/active_resource/base.rb:857:in `find_every' activeresource (3.0.1) lib/active_resource/base.rb:777:in `find' activeresource (3.0.1) lib/active_resource/base.rb:803:in `all' app/controllers/home_controller.rb:4:in `index' actionpack (3.0.1) lib/action_controller/metal/implicit_render.rb:4:in `send_action' actionpack (3.0.1) lib/abstract_controller/base.rb:150:in `process_action' actionpack (3.0.1) lib/action_controller/metal/rendering.rb:11:in `process_action' actionpack (3.0.1) lib/abstract_controller/callbacks.rb:18:in `block in process_action' activesupport (3.0.1) lib/active_support/callbacks.rb:435:in `_run__140584718597918073__process_action__4423897468290757938__callbacks' activesupport (3.0.1) lib/active_support/callbacks.rb:409:in `_run_process_action_callbacks' activesupport (3.0.1) lib/active_support/callbacks.rb:93:in `run_callbacks' actionpack (3.0.1) lib/abstract_controller/callbacks.rb:17:in `process_action' actionpack (3.0.1) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' activesupport (3.0.1) lib/active_support/notifications.rb:52:in `block in instrument' activesupport (3.0.1) lib/active_support/notifications/instrumenter.rb:21:in `instrument' activesupport (3.0.1) lib/active_support/notifications.rb:52:in `instrument' actionpack (3.0.1) lib/action_controller/metal/instrumentation.rb:29:in `process_action' actionpack (3.0.1) lib/action_controller/metal/rescue.rb:17:in `process_action' actionpack (3.0.1) lib/abstract_controller/base.rb:119:in `process' actionpack (3.0.1) lib/abstract_controller/rendering.rb:40:in `process' actionpack (3.0.1) lib/action_controller/metal.rb:133:in `dispatch' actionpack (3.0.1) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' actionpack (3.0.1) lib/action_controller/metal.rb:173:in `block in action' actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:62:in `call' actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:62:in `dispatch' actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:27:in `call' rack-mount (0.6.13) lib/rack/mount/route_set.rb:148:in `block in call' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:93:in `block in recognize' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:68:in `optimized_each' rack-mount (0.6.13) lib/rack/mount/code_generation.rb:92:in `recognize' rack-mount (0.6.13) lib/rack/mount/route_set.rb:139:in `call' actionpack (3.0.1) lib/action_dispatch/routing/route_set.rb:492:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/head.rb:14:in `call' rack (1.2.1) lib/rack/methodoverride.rb:24:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/params_parser.rb:21:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/flash.rb:182:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/session/abstract_store.rb:149:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/cookies.rb:287:in `call' activerecord (3.0.1) lib/active_record/query_cache.rb:32:in `block in call' activerecord (3.0.1) lib/active_record/connection_adapters/abstract/query_cache.rb:28:in `cache' activerecord (3.0.1) lib/active_record/query_cache.rb:12:in `cache' activerecord (3.0.1) lib/active_record/query_cache.rb:31:in `call' activerecord (3.0.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:355:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/callbacks.rb:46:in `block in call' activesupport (3.0.1) lib/active_support/callbacks.rb:415:in `_run_call_callbacks' actionpack (3.0.1) lib/action_dispatch/middleware/callbacks.rb:44:in `call' rack (1.2.1) lib/rack/sendfile.rb:107:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/remote_ip.rb:48:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/show_exceptions.rb:46:in `call' railties (3.0.1) lib/rails/rack/logger.rb:13:in `call' rack (1.2.1) lib/rack/runtime.rb:17:in `call' activesupport (3.0.1) lib/active_support/cache/strategy/local_cache.rb:72:in `call' rack (1.2.1) lib/rack/lock.rb:11:in `block in call' <internal:prelude>:10:in `synchronize' rack (1.2.1) lib/rack/lock.rb:11:in `call' actionpack (3.0.1) lib/action_dispatch/middleware/static.rb:30:in `call' railties (3.0.1) lib/rails/application.rb:168:in `call' railties (3.0.1) lib/rails/application.rb:77:in `method_missing' railties (3.0.1) lib/rails/rack/log_tailer.rb:14:in `call' rack (1.2.1) lib/rack/content_length.rb:13:in `call' rack (1.2.1) lib/rack/handler/webrick.rb:52:in `service' /Users/swright/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service' /Users/swright/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run' /Users/swright/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/server.rb:183:in `block in start_thread'

最满意答案

简单的回答，如果您尝试在视图中进行session ，它将访问Rails会话对象，您手上就会出现命名问题。

这就是为什么Hash错误即将来临，它试图访问会话哈希。

尝试类似的东西

<h1>List Sessions</h1> <% @sessions.each do |s| %> <div><%= s.title %></div> <% end %>

顺便说一下，您可以将控制器更改为：

class HomeController < ApplicationController def index @sessions = Session.all end end

Simple answer, if you try to session in your views it will access the Rails Session object, you have a naming problem on your hands.

Thats why the Hash error is coming, it tries to access the session Hash.

Try something like

<h1>List Sessions</h1> <% @sessions.each do |s| %> <div><%= s.title %></div> <% end %>

And by the way, you might change your controller to:

class HomeController < ApplicationController def index @sessions = Session.all end end