Nokogiri-搜索具有特定节点的元素

Question

我有以下示例XML: http://api.clicky.com/api/stats/4?site_id=32020&sitekey=71bf7c1681e22468&type=visitors,countries,searches(虚拟XML数据)

我想指定节点"countries"，然后搜索所有"items"并提取各种数据。我正在尝试这样做:

   xml = Nokogiri::XML(open("http://api.clicky.com/api/stats/4?site_id=32020&sitekey=71bf7c1681e22468&type=visitors,countries,searches"))
        @node = xml.xpath('//countries')
        @countries = @node.search('item').map do |item|
        %w[title value value_percent].each_with_object({}) do |n, o|
          o[n] = item.at(n).text
        end
      end
   end

但是这没有给出任何结果。如果我将xml剥离回http://api.clicky.com/api/stats/4?site_id=32020&sitekey=71bf7c1681e22468&type=visitors并执行:

   xml = Nokogiri::XML(open("http://api.clicky.com/api/stats/4?site_id=32020&sitekey=71bf7c1681e22468&type=countries"))
        @countries = @node.search('item').map do |item|
        %w[title value value_percent].each_with_object({}) do |n, o|
          o[n] = item.at(n).text
        end
      end
   end

这很好。

我哪里错了?

Answer 1

xpath-query将只匹配名称为" nations "的节点，而不匹配类型属性设置为" nations "的节点。因此，您需要搜索具有属性"type"且值设置为"nations"的节点

查找国家/地区所有项目的三种方法

  # (1) Find all nodes with a attribute "type" set to "countries"
  items = xml.xpath("//*[@type='countries']//item") 
  # (2) Find only nodes with name "type" and that has the attribute "type" set to "countries"
  items = xml.xpath("//type[@type='countries']//item") 
  # (3) By using css selectors; find only nodes with name "type" and that has the attribute "type" set to "countries"
  items = xml.css("type[type='countries'] item")