old_contents: from django.http import HttpResponse
  from django.conf.urls import url
  
  from wagtail.contrib.wagtailroutablepage.models import RoutablePage
  
  
  def routable_page_external_view(request, arg):
      return HttpResponse("EXTERNAL VIEW: " + arg)
  
  class RoutablePageTest(RoutablePage):
      @property
      def subpage_urls(self):
          return (
              url(r'^$', self.main, name='main'),
              url(r'^archive/year/(\d+)/$', self.archive_by_year, name='archive_by_year'),
              url(r'^archive/author/(?P<author_slug>.+)/$', self.archive_by_author, name='archive_by_author'),
              url(r'^external/(.+)/$', routable_page_external_view, name='external_view')
          )
  
      def archive_by_year(self, request, year):
          return HttpResponse("ARCHIVE BY YEAR: " + str(year))
  
      def archive_by_author(self, request, author_slug):
          return HttpResponse("ARCHIVE BY AUTHOR: " + author_slug)
  
      def main(self, request):
          return HttpResponse("MAIN VIEW")
  
new_contents: from django.http import HttpResponse
  from django.conf.urls import url
  
  from wagtail.contrib.wagtailroutablepage.models import RoutablePage
  
  
  def routable_page_external_view(request, arg):
      return HttpResponse("EXTERNAL VIEW: " + arg)
  
  class RoutablePageTest(RoutablePage):
      subpage_urls = (
          url(r'^$', 'main', name='main'),
          url(r'^archive/year/(\d+)/$', 'archive_by_year', name='archive_by_year'),
          url(r'^archive/author/(?P<author_slug>.+)/$', 'archive_by_author', name='archive_by_author'),
          url(r'^external/(.+)/$', routable_page_external_view, name='external_view')
      )
  
      def archive_by_year(self, request, year):
          return HttpResponse("ARCHIVE BY YEAR: " + str(year))
  
      def archive_by_author(self, request, author_slug):
          return HttpResponse("ARCHIVE BY AUTHOR: " + author_slug)
  
      def main(self, request):
          return HttpResponse("MAIN VIEW")
  
subject: Revert "Make subpage_urls a property on RoutablePageTest"