module Middleman::Sitemap::Extensions::Traversal

def children
  return [] unless directory_index?
  if eponymous_directory?
    base_path = eponymous_directory_path
    prefix    = %r|^#{base_path.sub("/", "\\/")}|
  else
    base_path = path.sub("#{app.index_file}", "")
    prefix    = %r|^#{base_path.sub("/", "\\/")}|
  end
  store.resources.select do |sub_resource|
    if sub_resource.path == self.path || sub_resource.path !~ prefix
      false
    else
      inner_path = sub_resource.path.sub(prefix, "")
      parts = inner_path.split("/")
      if parts.length == 1
        true
      elsif parts.length == 2
        parts.last == app.index_file
      else
        false
      end
    end
  end
end