ruby - rails的表单验证后格式错乱问题

Question

举个例子，在表单中有这样的内容： {代码...} 在浏览器中显示成： {代码...} (※注：■由CSS生成) 如果对表单进行验证，验证后再显示的格式就乱了，变成这样： {代码...} 为什么会错位呢？

天蓬老师 · Answer

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| 
   "#{html_tag}".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.

(Full text copied from http://stackoverflow.com/questions/5267998/rails-3-field-with-errors-wrapper-changes-the-page-appearance-how-to-avoid-t)

Of course, it is more recommended to change it to this

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