0

我正在修改 Rails 2 网站。现在，我遇到了一个错误，我认为这是因为一个值被提交为空白而不是 .nil。然而，我试图保持它为零似乎并没有奏效。感谢您提供的任何帮助。

来自模型，基于Make blank params[] nil

    NULL_ATTRS = %w( start_masterlocation_id )
    before_save :nil_if_blank

    protected

    def nil_if_blank
    NULL_ATTRS.each { |attr| self[attr] = nil if self[attr].blank? }
    end

看法

当 start_masterlocation_id 存在时，我有 jQuery 向这个隐藏字段添加一个值。我还有 jQuery，当它不存在时，它会删除字段属性。

    <%= hidden_field :newsavedmap, :start_masterlocation_id, :id => "start-masterlocation-id-field" %>

最后，这是控制器中抛出错误的部分。这是保存表单 (Maptry) 的页面的控制器，而不是 Newsavedmap 的控制器。我想我必须删除 @newsavedmap.id、@newsavedmap.mapname 和 @newsavedmap.optimize 行，因为我要使用表单处理程序，但我认为这与此错误无关。

控制器

    def maptry
    @itinerary = Itinerary.find(params[:id])
    if @itinerary.user_id == current_user.id
    respond_to do |format|
    @masterlocation = Masterlocation.find(:all)
    format.html do
    end
    format.xml  { render :xml => @masterlocation }
    format.js do
    @masterlocation = Masterlocation.find(:all)
    render :json => @masterlocation.to_json(:only => [:id, :nickname, :latitude, :longitude])
    end
    end
    if params[:newsavedmap_id]
    @newsavedmap = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]})
    @waypoint = Waypoint.find(:all, :conditions => {:newsavedmap_id => params[:newsavedmap_id]})
    @newsavedmap.id = params[:newsavedmap_id]
    @newsavedmap.mapname = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]}).mapname
    @newsavedmap.optimize = Newsavedmap.find(:first, :conditions => {:id => params[:newsavedmap_id]}).optimize
    if !@newsavedmap.start_masterlocation_id.nil?       
    @start_name = Masterlocation.find(:first, :conditions => {:id => @newsavedmap.start_masterlocation_id}).name
    end
    if !@newsavedmap.end_masterlocation_id.nil?     
    @end_name = Masterlocation.find(:first, :conditions => {:id => @newsavedmap.end_masterlocation_id}).name
    end
    else
    @newsavedmap = Newsavedmap.new  
    end
    else
    redirect_to '/'
    end
    end

错误 当数据库中存在 start_masterlocation_id 时，不会发生这种情况。

    undefined method `name' for nil:NilClass
4

1 回答 1

0

I solved this by ignoring the nil problem. Instead, I used 

    !@newsavedmap.start_masterlocation_id.blank?

This evaluates whether the data in the record is blank and then either does or doesn't do something. Obviously, this results in unwanted "blank" data being left inside my database, so it's not ideal, but it helped me move forward with the project. I'd appreciate any responses that deal directly with the nil issue and tell me how to have Rails ignore blank data in a form.

于 2013-09-21T15:18:25.327 回答