added default index_route for RoutablePageMixin

RoutablePageMixin has a default index_route method that is decorated
with `@route(r'^$')`. This way, including RoutablePageMixin doesn't
force you to re-enable the default functionality you would expect from a
Page anyways.
index_route behaves exactly like a standard Wagtail Page.
To override the default behaviour, one can simply override the route by
decorating another function with r'^$'.

(as disussed in issue #2866)

docs/reference/contrib/routablepage.rst

@@ -9,6 +9,7 @@
 The ``RoutablePageMixin`` mixin provides a convenient way for a page to respond on multiple sub-URLs with different views. For example, a blog section on a site might provide several different types of index page at URLs like ``/blog/2013/06/``, ``/blog/authors/bob/``, ``/blog/tagged/python/``, all served by the same page instance.
 
 A ``Page`` using ``RoutablePageMixin`` exists within the page tree like any other page, but URL paths underneath it are checked against a list of patterns. If none of the patterns match, control is passed to subpages as usual (or failing that, a 404 error is thrown).
+Per default a route for ``r'^$'`` exists, which serves the content exactly like a regular ``Page`` would. It can be overridden by using ``@route(r'^$')`` on any other method of the inheriting class.
 
 
 Installation
@@ -41,7 +42,7 @@ Here's an example of an ``EventPage`` with three views:
     class EventPage(RoutablePageMixin, Page):
         ...
 
-        @route(r'^$')
+        @route(r'^$') # will override the default Page serving mechanism
         def current_events(self, request):
             """
             View function for the current events page

wagtail/contrib/wagtailroutablepage/models.py

@@ -3,6 +3,7 @@ from __future__ import absolute_import, unicode_literals
 from django.conf.urls import url
 from django.core.urlresolvers import RegexURLResolver
 from django.http import Http404
+from django.template.response import TemplateResponse
 
 from wagtail.wagtailcore.models import Page
 from wagtail.wagtailcore.url_routing import RouteResult
@@ -35,6 +36,16 @@ class RoutablePageMixin(object):
     This class can be mixed in to a Page model, allowing extra routes to be
     added to it.
     """
+    @route(r'^$')
+    def index_route(self, request, *args, **kwargs):
+        request.is_preview = getattr(request, 'is_preview', False)
+
+        return TemplateResponse(
+            request,
+            self.get_template(request, *args, **kwargs),
+            self.get_context(request, *args, **kwargs)
+        )
+
     @classmethod
     def get_subpage_urls(cls):
         routes = []
@@ -45,7 +56,7 @@ class RoutablePageMixin(object):
 
         return tuple([
             route[0]
-            for route in sorted(routes, key=lambda route: route[1])
+            for route in reversed(sorted(routes, key=lambda route: route[1]))
         ])
 
     @classmethod

wagtail/contrib/wagtailroutablepage/tests.py

@@ -5,7 +5,7 @@ from django.test import RequestFactory, TestCase
 
 from wagtail.contrib.wagtailroutablepage.templatetags.wagtailroutablepage_tags import \
     routablepageurl
-from wagtail.tests.routablepage.models import RoutablePageTest, RoutablePageWithoutIndexRouteTest
+from wagtail.tests.routablepage.models import RoutablePageTest, RoutablePageWithOverriddenIndexRouteTest
 from wagtail.wagtailcore.models import Page, Site
 
 
@@ -19,10 +19,10 @@ class TestRoutablePage(TestCase):
             live=True,
         ))
 
-    def test_resolve_main_view(self):
+    def test_resolve_index_route_view(self):
         view, args, kwargs = self.routable_page.resolve_subpage('/')
 
-        self.assertEqual(view, self.routable_page.main)
+        self.assertEqual(view, self.routable_page.index_route)
         self.assertEqual(args, ())
         self.assertEqual(kwargs, {})
 
@@ -54,8 +54,8 @@ class TestRoutablePage(TestCase):
         self.assertEqual(args, ())
         self.assertEqual(kwargs, {})
 
-    def test_reverse_main_view(self):
-        url = self.routable_page.reverse_subpage('main')
+    def test_reverse_index_route_view(self):
+        url = self.routable_page.reverse_subpage('index_route')
 
         self.assertEqual(url, '')
 
@@ -88,20 +88,21 @@ class TestRoutablePage(TestCase):
 
         self.assertEqual(url, 'external-no-arg/')
 
-    def test_get_main_view(self):
+    def test_get_index_route_view(self):
         response = self.client.get(self.routable_page.url)
 
-        self.assertContains(response, "MAIN VIEW")
+        self.assertContains(response, "DEFAULT PAGE TEMPLATE")
 
-    def test_get_routable_page_without_index_route(self):
+    def test_get_routable_page_with_overridden_index_route(self):
         page = self.home_page.add_child(
-            instance=RoutablePageWithoutIndexRouteTest(
-                title="Routable Page without index",
+            instance=RoutablePageWithOverriddenIndexRouteTest(
+                title="Routable Page with overridden index",
                 live=True
             )
         )
         response = self.client.get(page.url)
-        self.assertContains(response, "DEFAULT PAGE TEMPLATE")
+        self.assertContains(response, "OVERRIDDEN INDEX ROUTE")
+        self.assertNotContains(response, "DEFAULT PAGE TEMPLATE")
 
     def test_get_archive_by_year_view(self):
         response = self.client.get(self.routable_page.url + 'archive/year/2014/')
@@ -156,9 +157,9 @@ class TestRoutablePageTemplateTag(TestCase):
         self.request.site = Site.find_for_request(self.request)
         self.context = {'request': self.request}
 
-    def test_templatetag_reverse_main_view(self):
+    def test_templatetag_reverse_index_route(self):
         url = routablepageurl(self.context, self.routable_page,
-                              'main')
+                              'index_route')
         self.assertEqual(url, self.routable_page.url)
 
     def test_templatetag_reverse_archive_by_year_view(self):

wagtail/tests/routablepage/migrations/0002_routablepagewithoutindexroutetest.py

@@ -16,7 +16,7 @@ class Migration(migrations.Migration):
 
     operations = [
         migrations.CreateModel(
-            name='RoutablePageWithoutIndexRouteTest',
+            name='RoutablePageWithOverriddenIndexRouteTest',
             fields=[
                 ('page_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='wagtailcore.Page')),
             ],

wagtail/tests/routablepage/models.py

@@ -10,9 +10,6 @@ def routable_page_external_view(request, arg="ARG NOT SET"):
 
 
 class RoutablePageTest(RoutablePage):
-    @route(r'^$')
-    def main(self, request):
-        return HttpResponse("MAIN VIEW")
 
     @route(r'^archive/year/(\d+)/$')
     def archive_by_year(self, request, year):
@@ -34,5 +31,7 @@ class RoutablePageTest(RoutablePage):
         pass
 
 
-class RoutablePageWithoutIndexRouteTest(RoutablePage):
-    pass
+class RoutablePageWithOverriddenIndexRouteTest(RoutablePage):
+    @route(r'^$')
+    def main(self, request):
+        return HttpResponse("OVERRIDDEN INDEX ROUTE")