How do I access HTML elements that are rendered in JavaScript using XPath?

问题

How do I get a <td> with a specific class name using XPath and Nokogiri? Tables are nested and some of them don't have IDs or classes, so I can't nest stuff like this:

//table/tbody/tr/td

Here is what I have so far:

doc = Nokogiri::HTML(open("http://www.goalzz.com/default.aspx?c=8358"))
  doc.xpath('//td[@class="m_g"]').each do |node|
  pp node.to_s
end

Any ideas? There are few <td>s with that class name and I want to get all of them.

回答1:

Using gem "capybara-webkit" is a viable way of manipulating this website in full javascript rendered view.

Here is a scratch example of what a capybara-webkit script might look like.

#!/usr/bin/env ruby
require "rubygems"
require "pp"
require "bundler/setup"
require "capybara"
require "capybara/dsl"
require "capybara-webkit"

Capybara.run_server = false
Capybara.current_driver = :webkit
Capybara.app_host = "http://www.goalzz.com/"

module Test
  class Goalzz
    include Capybara::DSL

    def get_results
      visit('/default.aspx?c=8358')
      all(:xpath, '//td[@class="m_g"]').each { |node| pp node.to_s }

    end
  end
end

spider = Test::Goalzz.new
spider.get_results

What is required to find the example xpath in this case (due to the page being created dynamically), is a fully functional javascript webdriving engine.

回答2:

Are the class attributes on these tds exactly "m_g", or do they have more than one class on a single td? If it's the latter, this XPath might work:

//td[contains(@class, "m_g")]

来源：https://stackoverflow.com/questions/14263532/how-do-i-access-html-elements-that-are-rendered-in-javascript-using-xpath

标签

ruby

xpath

nokogiri