将ActiveResource与Rails 3和REST API一起使用时出错

时间：2010-10-26 17:38:44

标签： ruby-on-rails rest ruby-on-rails-3 activeresource

我有一个REST API，我试图使用返回的Rails 3.0.1访问：

<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的网址为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

我的视图index.html.erb已定义：

<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（即使使用http://example.com/rest/sessions.xml）。有没有办法调试ActiveResource来查看里面发生了什么？

修改

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'

3 个答案:

答案 0 :(得分：3)

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

这就是Hash错误即将发生的原因，它试图访问会话Hash。

尝试类似

的内容 
<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

答案 1 :(得分：1)

对我来说，问题是xml标签中没有定义类型

xml.instruct!
xml.posts("type"=>"array") do
  @posts.each do |p|
    xml.post do 
      xml.id("type"=>"integer") do
        p.id
      end
      xml.title p.title
      xml.content p.content
    end
  end
end

vs 

xml.instruct!
xml.posts do
  @posts.each do |p|
    xml.post do 
      xml.id p.id
      xml.title p.title
      xml.content p.content
    end
  end
end

希望这有助于你

答案 2 :(得分：1)

我有这个问题，就像上面的Joel一样，这是因为没有定义类型。我找到了一个解决方案here，但是如果您对XML没有任何控制权，您可以定义一个自定义格式，并告诉您的ActiveResource类使用它：

class TaxAlert < ActiveResource::Base
  protected

  class CustomFormat
    include ActiveResource::Formats::XmlFormat

    def decode(xml)
      ActiveResource::Formats::XmlFormat.decode(xml)['alert']
    end
  end

  self.format = CustomFormat.new
end
相关问题
最新问题