回形針 - 未定義的方法匹配零：NilClass

Question

我是新來的鐵軌和紅寶石。我正在創建一個可以上傳照片的簡單應用程序。我已經安裝了回形針寶石，我想我的模型中對其進行配置，以指定一個縮略圖大小，像這樣：

has_attached_file :photo, 
    :styles => {:thumb => '120x120>', :large => '640x480>' }, 
    :default_style => :thumb, 
    :url => "/system/photos/:basename.:extension", 
    :path => ":rails_root/public/system/photos/:basename.:extension" 

不過，我不斷收到錯誤：

undefined method `match' for nil:NilClass 

當我刪除：styles參數，一切都按預期工作。

任何人都可以擺脫一些光線並指向正確的方向嗎？

感謝

編輯：

堆棧跟蹤如下：

C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/content_type_detector.rb:60:in `type_from_file_command' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/content_type_detector.rb:16:in `detect' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/io_adapters/file_adapter.rb:14:in `cache_current_values' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/io_adapters/file_adapter.rb:5:in `initialize' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/io_adapters/registry.rb:29:in `new' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/io_adapters/registry.rb:29:in `for' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/attachment.rb:412:in `post_process_style' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/attachment.rb:402:in `block in post_process_styles' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/attachment.rb:401:in `each' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/attachment.rb:401:in `post_process_styles' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/attachment.rb:394:in `block (2 levels) in post_process' 
activesupport (3.2.7) lib/active_support/callbacks.rb:403:in `_run__792123923__photo_post_process__530674861__callbacks' 
activesupport (3.2.7) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.7) lib/active_support/callbacks.rb:385:in `_run_photo_post_process_callbacks' 
activesupport (3.2.7) lib/active_support/callbacks.rb:81:in `run_callbacks' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/callbacks.rb:26:in `run_paperclip_callbacks' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/attachment.rb:393:in `block in post_process' 
activesupport (3.2.7) lib/active_support/callbacks.rb:403:in `_run__792123923__post_process__530674861__callbacks' 
activesupport (3.2.7) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.7) lib/active_support/callbacks.rb:385:in `_run_post_process_callbacks' 
activesupport (3.2.7) lib/active_support/callbacks.rb:81:in `run_callbacks' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/callbacks.rb:26:in `run_paperclip_callbacks' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/attachment.rb:392:in `post_process' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip/attachment.rb:107:in `assign' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/bundler/gems/paperclip-70f0f1fea030/lib/paperclip.rb:196:in `block in has_attached_file' 
activerecord (3.2.7) lib/active_record/attribute_assignment.rb:85:in `block in assign_attributes' 
activerecord (3.2.7) lib/active_record/attribute_assignment.rb:78:in `each' 
activerecord (3.2.7) lib/active_record/attribute_assignment.rb:78:in `assign_attributes' 
activerecord (3.2.7) lib/active_record/base.rb:498:in `initialize' 
activerecord (3.2.7) lib/active_record/persistence.rb:44:in `new' 
activerecord (3.2.7) lib/active_record/persistence.rb:44:in `create' 
app/controllers/photography_controller.rb:23:in `create' 
actionpack (3.2.7) lib/action_controller/metal/implicit_render.rb:4:in `send_action' 
actionpack (3.2.7) lib/abstract_controller/base.rb:167:in `process_action' 
actionpack (3.2.7) lib/action_controller/metal/rendering.rb:10:in `process_action' 
actionpack (3.2.7) lib/abstract_controller/callbacks.rb:18:in `block in process_action' 
activesupport (3.2.7) lib/active_support/callbacks.rb:414:in `_run__403597772__process_action__67609296__callbacks' 
activesupport (3.2.7) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.7) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks' 
activesupport (3.2.7) lib/active_support/callbacks.rb:81:in `run_callbacks' 
actionpack (3.2.7) lib/abstract_controller/callbacks.rb:17:in `process_action' 
actionpack (3.2.7) lib/action_controller/metal/rescue.rb:29:in `process_action' 
actionpack (3.2.7) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' 
activesupport (3.2.7) lib/active_support/notifications.rb:123:in `block in instrument' 
activesupport (3.2.7) lib/active_support/notifications/instrumenter.rb:20:in `instrument' 
activesupport (3.2.7) lib/active_support/notifications.rb:123:in `instrument' 
actionpack (3.2.7) lib/action_controller/metal/instrumentation.rb:29:in `process_action' 
actionpack (3.2.7) lib/action_controller/metal/params_wrapper.rb:207:in `process_action' 
activerecord (3.2.7) lib/active_record/railties/controller_runtime.rb:18:in `process_action' 
actionpack (3.2.7) lib/abstract_controller/base.rb:121:in `process' 
actionpack (3.2.7) lib/abstract_controller/rendering.rb:45:in `process' 
actionpack (3.2.7) lib/action_controller/metal.rb:203:in `dispatch' 
actionpack (3.2.7) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' 
actionpack (3.2.7) lib/action_controller/metal.rb:246:in `block in action' 
actionpack (3.2.7) lib/action_dispatch/routing/route_set.rb:73:in `call' 
actionpack (3.2.7) lib/action_dispatch/routing/route_set.rb:73:in `dispatch' 
actionpack (3.2.7) lib/action_dispatch/routing/route_set.rb:36:in `call' 
journey (1.0.4) lib/journey/router.rb:68:in `block in call' 
journey (1.0.4) lib/journey/router.rb:56:in `each' 
journey (1.0.4) lib/journey/router.rb:56:in `call' 
actionpack (3.2.7) lib/action_dispatch/routing/route_set.rb:600:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call' 
rack (1.4.1) lib/rack/etag.rb:23:in `call' 
rack (1.4.1) lib/rack/conditionalget.rb:35:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/head.rb:14:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/params_parser.rb:21:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/flash.rb:242:in `call' 
rack (1.4.1) lib/rack/session/abstract/id.rb:205:in `context' 
rack (1.4.1) lib/rack/session/abstract/id.rb:200:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/cookies.rb:338:in `call' 
activerecord (3.2.7) lib/active_record/query_cache.rb:64:in `call' 
activerecord (3.2.7) lib/active_record/connection_adapters/abstract/connection_pool.rb:473:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call' 
activesupport (3.2.7) lib/active_support/callbacks.rb:405:in `_run__122749671__call__530674861__callbacks' 
activesupport (3.2.7) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.7) lib/active_support/callbacks.rb:385:in `_run_call_callbacks' 
activesupport (3.2.7) lib/active_support/callbacks.rb:81:in `run_callbacks' 
actionpack (3.2.7) lib/action_dispatch/middleware/callbacks.rb:27:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/reloader.rb:65:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/remote_ip.rb:31:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call' 
railties (3.2.7) lib/rails/rack/logger.rb:26:in `call_app' 
railties (3.2.7) lib/rails/rack/logger.rb:16:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/request_id.rb:22:in `call' 
rack (1.4.1) lib/rack/methodoverride.rb:21:in `call' 
rack (1.4.1) lib/rack/runtime.rb:17:in `call' 
activesupport (3.2.7) lib/active_support/cache/strategy/local_cache.rb:72:in `call' 
rack (1.4.1) lib/rack/lock.rb:15:in `call' 
actionpack (3.2.7) lib/action_dispatch/middleware/static.rb:62:in `call' 
railties (3.2.7) lib/rails/engine.rb:479:in `call' 
railties (3.2.7) lib/rails/application.rb:220:in `call' 
rack (1.4.1) lib/rack/content_length.rb:14:in `call' 
railties (3.2.7) lib/rails/rack/log_tailer.rb:17:in `call' 
rack (1.4.1) lib/rack/handler/webrick.rb:59:in `service' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread' 

PhotographyController：

def create 
    @photo = Photo.create(params[:photo]) 
end 

最後，我的表單部分可能會有所幫助：

<%= form_for @photo, :url => { :controller => 'photography', :action => 'create'}, :html => { :multipart => true } do |f| %> 
    <% if @photo.errors.any? %> 
    <div id="errorExplanation"> 
    <h2><%= pluralize(@photo.errors.count, "error") %> prohibited 
     this photo from being saved:</h2> 
    <ul> 
    <% @photo.errors.full_messages.each do |msg| %> 
     <li><%= msg %></li> 
    <% end %> 
    </ul> 
    </div> 
    <% end %> 

    <div class="field"> 
    <%= f.label :title %><br /> 
    <%= f.text_field :title %> 
    </div> 
    <div class="field"> 
    <%= f.label :description %><br /> 
    <%= f.text_area :description %> 
    </div> 
    <%= f.file_field :photo %> 
    <div class="actions"> 
    <%= f.submit ('Upload Photo') %> 
    </div> 
<% end %> 

再次感謝。

Answer 1

我遇到了這個錯誤，以及其他類似的錯誤，使用回形針。但是我在Windows上運行我的開發環境，最新版本的回形針使用`file'命令，這些窗口似乎並不那麼喜歡。

希望這個問題很快就會解決，但現在我用了最後一個可用的回形針，即3.0.4來回避這個問題。

如果你在Windows上運行的好，只是添加到您的Gemfile：

gem 'paperclip', '3.0.4' 

附：嘗試在開發中使用3.0.4以及生產的最新版本可能是值得的。