ruby-on-rails - 在此操作中多次调用渲染和/或重定向。

Question

我不断收到 DoubleRenderError，但我不知道为什么!基本上，我有一个 Action 调用另一个 Action 来检查用户输入的查询是否有错误，如果有错误，它会停止并显示错误。但是当我输入一个错误的查询时，当我得到双重渲染时!有什么建议吗？

这是错误检查器操作:

def if_user_formulated_request_properly
    unless request.post?
      flash[:error] = "This page can only be accessed through the search page. (POST request only)"
 redirect_to(:action => "index") and return
    end

    if params[:query].blank?
      flash[:error] = "Search criteria can not be blank"
redirect_to(:action => "index") and  return
    end

    if !(params[:query] =~ /-/)
      flash[:error] = "( Format of search criteria is wrong.<br /> Should be [IXLSpecClass value][year]-[Message ID] for exam
ple GP07-8)"
redirect_to(:action => "index") and  return
    end

    if !(QueryParser.expression.match(params[:query]))
      flash[:error] = %( Format of search criteria is wrong.<br />Should be [IXLSpecClass value][year]-[Message ID] for examp
le GP07-8)
redirect_to(:action => "index") and return
  end
 yield

以防万一您需要调用此操作的操作..

 def show
        if_user_formulated_request_properly do
        @statuses = IXLStatus.find(:all)
        @input_messages = InputMessage.search_by(params[:query].stri
p) unless params[:query].blank?
        @query = params[:query]
        end
        respond_to do |format|
          format.html #default rendering
        end
        end
  end

更新

还忘了提，这最初是一个 rails 2 应用程序并且正在运行，当我升级到 rails 3 时开始出现这个错误(我相信)，所以也许 rails 3 与 and return 做了一些不同的事情?

Answer 1

你只是从 if_user_formulated_request_properly 回来方法，这意味着 redirect_to和 respond_to做一个渲染。

你可以试试这个:

def user_formulated_request_properly?
  unless request.post?
    flash[:error] = "This page can only be accessed through the search page. (POST request only)"
    return false
  end

  if params[:query].blank?
    flash[:error] = "Search criteria can not be blank"
    return false
  end

  if !(params[:query] =~ /-/)
    flash[:error] = "( Format of search criteria is wrong.<br /> Should be [IXLSpecClass value][year]-[Message ID] for example GP07-8)"
    return false
  end

  if !(QueryParser.expression.match(params[:query]))
    flash[:error] = %( Format of search criteria is wrong.<br />Should be [IXLSpecClass value][year]-[Message ID] for example GP07-8)
    return false
  end

  return true
end


def show
  if user_formulated_request_properly?
    @statuses = IXLStatus.find(:all)
    @input_messages = InputMessage.search_by(params[:query].strip) unless params[:query].blank?
    @query = params[:query]
  else
    redirect_to(:action => "index") and return
  end

  respond_to do |format|
    format.html #default rendering
  end
end