ruby-on-rails - 在 Rails 3 和 REST API 中使用 ActiveResource 时出错

Question

我有一个 REST API，我试图使用 Rails 3.0.1 访问它，它返回:

<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 类定义:

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

将返回 XML 的 url 是 http://example.com/rest/sessions .

然后我有一个定义如下的 Controller :

class HomeController < ApplicationController
  def index
    Session.all
  end
end

我的 View index.html.erb 是这样定义的:

<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 中的 NoMethodError#index

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

什么可能导致这个问题？我可以很好地访问网址(即使使用 http://example.com/rest/sessions.xml )。有没有办法调试 ActiveResource 以查看内部发生了什么？

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'

Answer 1

简单的答案，如果您尝试 session在您的 View 中，它将访问 Rails Session 对象，您手头有命名问题。

这就是为什么会出现 Hash 错误的原因，它会尝试访问 session Hash。

尝试类似的东西

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

顺便说一句，您可以将 Controller 更改为:

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