Ruby on rails 带rails的amcharts-不获取数据馈送

我目前的工作如下：

我很容易地完成了这一切，但是当查看带有图表的页面时，它（在flash中）加载了一个黑色矩形，其中包含错误：

“加载文件时出错”

评论中有人说这可能与XMLBuilder文件中的代码有关

  xml.instruct!  :xml, :version=>"1.0", :encoding=>"UTF-8"
  xml.chart do
    # xml.message "You can broadcast any message to chart from data XML file", :bg_color => "#FFFFFF", :text_color => "#000000"
    xml.series do    
      @cities.each_with_index do |city, index|
        xml.value city.name,  :xid => index
      end
    end

    xml.graphs do
     #the gid is used in the settings file to set different settings just for this graph
      xml.graph :gid => 'population' do
        @cities.each_with_index do |city, index|
          population = city.population
          case population
            # When the population is > 1 million, show the bar in red/pink
            when > 100000
              xml.value value,  :xid => index, :color => "#ff43a8", :gradient_fill_colors => "#960040,#ff43a8", :description => level
            else
              xml.value value,  :xid => index, :color => "#00C3C6", :gradient_fill_colors => "#009c9d,#00C3C6", :description => level
            end
        end
      end
    end

  end

我不确定错误是从哪里来的，但我希望得到任何帮助

最好的， 埃利奥特

我知道了

          xml.value value,  :xid => index, :color => "#00C3C6", :gradient_fill_colors => "#009c9d,#00C3C6", :description => level

在该行中，未定义第二个“值”和“级别”变量。一旦他们成功了，一切都会成功