added convenience method in_site and tests

CHANGELOG.txt

@@ -23,6 +23,7 @@ Changelog
  * `ChoiceBlock` now accepts a callable as the choices list (Mikalai Radchuk)
  * Redundant action buttons are now omitted from the root page in the explorer (Nick Smith)
  * Locked pages are now disabled from editing at the browser level (Edd Baldry)
+ * Added `in_site` method for filtering page querysets to pages within the specified site (Chris Rogers)
  * Fix: `AbstractForm` now respects custom `get_template` methods on the page model (Gagaro)
  * Fix: Use specific page model for the parent page in the explore index (Gagaro)
  * Fix: Remove responsive styles in embed when there is no ratio available (Gagaro)

docs/reference/pages/queryset_reference.rst

@@ -71,6 +71,15 @@ Reference
 
     .. automethod:: not_in_menu
 
+    .. automethod:: in_site
+
+        Example:
+
+        .. code-block:: python
+
+            # Get all the EventPages in the current site
+            site_events = EventPage.objects.in_site(request.site)
+
     .. automethod:: page
 
         Example:

docs/releases/1.8.rst

@@ -54,6 +54,7 @@ Minor features
  * ``ChoiceBlock`` now accepts a callable as the choices list (Mikalai Radchuk)
  * Redundant action buttons are now omitted from the root page in the explorer (Nick Smith)
  * Locked pages are now disabled from editing at the browser level (Edd Baldry)
+ * Added :meth:`wagtail.wagtailcore.query.PageQuerySet.in_site` method for filtering page querysets to pages within the specified site (Chris Rogers)
 
 
 Bug fixes

wagtail/wagtailcore/query.py

@@ -350,6 +350,12 @@ class PageQuerySet(SearchableQuerySetMixin, TreeQuerySet):
         else:
             return self._clone(klass=SpecificQuerySet)
 
+    def in_site(self, site):
+        """
+        This filters the QuerySet to only contain pages within the specified site.
+        """
+        return self.descendant_of(site.root_page, inclusive=True)
+
 
 def specific_iterator(qs):
     """

wagtail/wagtailcore/tests/test_page_queryset.py

@@ -2,8 +2,8 @@ from __future__ import absolute_import, unicode_literals
 
 from django.test import TestCase
 
-from wagtail.tests.testapp.models import EventPage, SingleEventPage
-from wagtail.wagtailcore.models import Page, PageViewRestriction
+from wagtail.tests.testapp.models import EventPage, SimplePage, SingleEventPage
+from wagtail.wagtailcore.models import Page, PageViewRestriction, Site
 from wagtail.wagtailcore.signals import page_unpublished
 
 
@@ -398,6 +398,39 @@ class TestPageQuerySet(TestCase):
         self.assertTrue(pages.filter(id=event.id).exists())
 
 
+class TestPageQueryInSite(TestCase):
+    fixtures = ['test.json']
+
+    def setUp(self):
+        self.site_2_page = SimplePage(
+            title="Site 2 page",
+            slug="site_2_page",
+            content="Hello",
+        )
+        Page.get_first_root_node().add_child(instance=self.site_2_page)
+        self.site_2_subpage = SimplePage(
+            title="Site 2 subpage",
+            slug="site_2_subpage",
+            content="Hello again",
+        )
+        self.site_2_page.add_child(instance=self.site_2_subpage)
+
+        self.site_2 = Site.objects.create(
+            hostname='example.com',
+            port=8080,
+            root_page=Page.objects.get(pk=self.site_2_page.pk),
+            is_default_site=False
+        )
+        self.about_us_page = SimplePage.objects.get(url_path='/home/about-us/')
+
+    def test_in_site(self):
+        site_2_pages = SimplePage.objects.in_site(self.site_2)
+
+        self.assertIn(self.site_2_page, site_2_pages)
+        self.assertIn(self.site_2_subpage, site_2_pages)
+        self.assertNotIn(self.about_us_page, site_2_pages)
+
+
 class TestPageQuerySetSearch(TestCase):
     fixtures = ['test.json']