ruby - rails的表單驗證後格式錯亂問題

Question

舉個例子，在表單中有這樣的內容：

    <dl>                                                                                                                                                                                                                                                                        
      <dt>
        <%= f.label :subject %>
      </dt>
      <dd>
        <%= f.text_field :subject %>
      </dd>
    </dl>

在瀏覽器中顯示成：

■Subject

(※注：■由CSS生成)

如果對表單進行驗證，驗證後再顯示的格式就亂了，變成這樣：

■
Subject

為什麼會錯位呢？

Answer 1

You should override ActionView::Base.field_error_proc. It's currently defined as this within ActionView::Base:

 @@field_error_proc = Proc.new{ |html_tag, instance| 
   "<p class=\"field_with_errors\">#{html_tag}</p>".html_safe
 }

You can override it by putting this in your application's class inside config/application.rb:

config.action_view.field_error_proc = Proc.new { |html_tag, instance| 
  "#{html_tag}".html_safe 
}

Restart rails server for this change to take effect.

（全文抄襲自 http://stackoverflow.com/questions/5267998/rails-3-field-with-errors-wrapper-changes-the-page-appearance-how-to-avoid-t）

---

當然，更推薦改成這樣

config.action_view.field_error_proc = Proc.new do |html_tag, instance|
  class_attr_index = html_tag.index 'class='

  if class_attr_index
    html_tag.insert class_attr_index+7, 'error '
  else
    html_tag.insert html_tag.index('>'), ' class="error"'
  end
end