Rails flash 抛出参数数量错误 (0 for 2) 错误

Question

我刚刚将一个应用程序从rails 1.2.3升级到rails 2.0.2（我首先尝试了2.3.2但失败了）。 我必须对插件进行一些调整，但总体进展顺利。 也就是说，直到我意识到我的闪光灯不起作用。 因此，我随后降级回 1.2.3，但仍然收到以下错误：

ActionView::TemplateError (wrong number of arguments (0 for 2))

来自我在视图中第一次调用 flash 的位置

<%= render :partial => "flash_msg", :object => flash %>

flash_msg 模板是：

<% if flash[:notice] %>
    <div class="notice"><%= flash[:notice] %></div>
<% elsif flash[:warning] %>
    <div class="warning"><%= flash[:warning] %></div>
<% end %>

完整跟踪是：

ActionView::TemplateError (wrong number of arguments (0 for 2)) on line #53 of layouts/store.rhtml:
50: 
51:             <div class="col-left">
52:                 
53:                 <%= render :partial => "user/flash_msg", :object => flash %>
54:         
app/views/layouts/store.rhtml:53:in `flash'
app/views/layouts/store.rhtml:53:in `_run_erb_47app47views47layouts47store46rhtml'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:637:in `send'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:637:in `compile_and_render_template'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:365:in `render_template'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_view/base.rb:316:in `render_file'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/layout.rb:268:in `render_without_benchmark'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:51:in `render'
/opt/local/lib/ruby/1.8/benchmark.rb:293:in `measure'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:51:in `render'
app/controllers/store_controller.rb:75:in `browse'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1158:in `send'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1158:in `perform_action_without_filters'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:697:in `call_filters'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:689:in `perform_action_without_benchmark'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/opt/local/lib/ruby/1.8/benchmark.rb:293:in `measure'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/rescue.rb:199:in `perform_action_without_caching'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:678:in `perform_action'
/opt/local/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/connection_adapters/abstract/query_cache.rb:33:in `cache'
/opt/local/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/query_cache.rb:8:in `cache'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:677:in `perform_action'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in `send'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in `process_without_filters'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:685:in `process_without_session_management_support'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/session_management.rb:123:in `process'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:388:in `process'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:171:in `handle_request'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:115:in `dispatch'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:126:in `dispatch_cgi'
/opt/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:9:in `dispatch'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel/rails.rb:78:in `process'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel/rails.rb:76:in `synchronize'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel/rails.rb:76:in `process'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:618:in `process_client'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:617:in `each'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:617:in `process_client'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:736:in `run'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:736:in `initialize'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:736:in `new'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:736:in `run'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:720:in `initialize'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:720:in `new'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel.rb:720:in `run'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel/configurator.rb:271:in `run'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel/configurator.rb:270:in `each'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel/configurator.rb:270:in `run'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/bin/mongrel_rails:127:in `run'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/lib/mongrel/command.rb:211:in `run'
/opt/local/lib/ruby/gems/1.8/gems/mongrel-1.0.1/bin/mongrel_rails:243
/opt/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:489:in `load'
/opt/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:489:in `load'
/opt/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
/opt/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:489:in `load'
/opt/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/commands/servers/mongrel.rb:64
/opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
/opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
/opt/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in `require'
/opt/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:342:in `new_constants_in'
/opt/local/lib/ruby/gems/1.8/gems/activesupport-2.0.2/lib/active_support/dependencies.rb:496:in `require'
/opt/local/lib/ruby/gems/1.8/gems/rails-2.0.2/lib/commands/server.rb:39
/opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
/opt/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
script/server:3

Answer 1

一种可能性是某些东西（或某人）可能定义了一个 flash 方法，该方法会覆盖默认的 flash 行为。 即在某个地方定义了一个 flash 方法，它需要 2 个参数，并且在有 flash[:notice] 的地方，它调用 flash 方法并失败。

Answer 2

@Shadwell，你是完全正确的！ 有一个名为“flash”的视图辅助函数，rails 2+ 不喜欢！

所以我了解到 Rails 1.2.3 中名为“flash”的辅助函数不会覆盖 flash 哈希。 在 Rails 2+ 中它会的。

Answer 3

尝试删除“:object => flash”。 我认为您的部分将可以访问 flash，而无需将其作为 :object 传递。

Answer 4

我这样做了，错误只是转移到 flash_msg 部分：

wrong number of arguments (0 for 2)

提取的源代码（围绕第 1 行）：

1: <% if flash[:notice] %>
2:  <div class="notice"><%= flash[:notice] %></div>
3: <% elsif flash[:warning] %>
4:  <div class="warning"><%= flash[:warning] %></div>

Answer 5

经过更多研究后，我发现一旦渲染视图，Flash 就不再起作用。 例如，整个控制器中的 flash.class 返回：

ActionController::Flash::FlashHash

但是当我尝试在视图中获取 flash.class 时，我会得到上面相同的错误。

如果我给它两个参数，它会返回“String”。 例如：

flash(nil, nil).class = String

这对任何人都有帮助吗？