Custom function for class check in Nokogiri-CodePudding

How can I add a custom XPath function for class check to Nokogiri?

I.e. something like https://gist.github.com/knu/087b7f89bb31de4f419c, but performing

contains(concat(' ',normalize-space(@class),' '),' #{class_name} ')

Thanks :)

CodePudding user response：

The following seems to work:

require 'nokogiri'
require 'singleton'

class CustomFunctions
  include Singleton

  # Implements: contains(concat(' ',normalize-space(@class),' '),' #{class_name} ')
  def contains_class(nodeset, class_name)
    nodeset.any? do |node|
      attribute_value = node['class']
      !attribute_value.nil? && attribute_value.split(' ').include?(class_name)
    end
  end

  alias_method :'contains-class', :contains_class

  module SetDefaultHandler
    private

    def extract_params(args)
      params = super
      params[1] ||= CustomFunctions.instance
      params
    end

    Nokogiri::XML::Node.prepend self
    Nokogiri::XML::NodeSet.prepend self
  end
end

xml = Nokogiri::XML('<html><body><div >ascabsc</div><div >zjtzj</div></body></html>')
xml.root.add_namespace('fn', 'http://www.w3.org/2005/xpath-functions')

%w[a2 a3].each do |class_name|
  puts "Test #{class_name}: "   xml.xpath(".//div[fn:contains-class(., \"#{class_name}\")]").to_s
end