Bypass 'choose a page type' screen when there is only one available choice in subpage_types

wagtail/tests/models.py

@@ -303,6 +303,9 @@ class StandardChild(Page):
     pass
 
 class BusinessIndex(Page):
+    subpage_types = ['tests.BusinessChild', 'tests.BusinessSubIndex']
+
+class BusinessSubIndex(Page):
     subpage_types = ['tests.BusinessChild']
 
 class BusinessChild(Page):

wagtail/wagtailadmin/tests/test_pages_views.py

@@ -1,5 +1,5 @@
 from django.test import TestCase
-from wagtail.tests.models import SimplePage, EventPage, StandardIndex, StandardChild, BusinessIndex, BusinessChild
+from wagtail.tests.models import SimplePage, EventPage, StandardIndex, StandardChild, BusinessIndex, BusinessChild, BusinessSubIndex
 from wagtail.tests.utils import unittest, WagtailTestUtils
 from wagtail.wagtailcore.models import Page, PageRevision
 from django.core.urlresolvers import reverse
@@ -681,24 +681,30 @@ class TestSubpageBusinessRules(TestCase, WagtailTestUtils):
         # Find root page
         self.root_page = Page.objects.get(id=2)
 
-        # Add standard page
+        # Add standard page (allows subpages of any type)
         self.standard_index = StandardIndex()
         self.standard_index.title = "Standard Index"
         self.standard_index.slug = "standard-index"
         self.root_page.add_child(instance=self.standard_index)
 
-        # Add business page
+        # Add business page (allows BusinessChild and BusinessSubIndex as subpages)
         self.business_index = BusinessIndex()
         self.business_index.title = "Business Index"
         self.business_index.slug = "business-index"
         self.root_page.add_child(instance=self.business_index)
 
-        # Add business child
+        # Add business child (allows no subpages)
         self.business_child = BusinessChild()
         self.business_child.title = "Business Child"
         self.business_child.slug = "business-child"
         self.business_index.add_child(instance=self.business_child)
 
+        # Add business subindex (allows only BusinessChild as subpages)
+        self.business_subindex = BusinessSubIndex()
+        self.business_subindex.title = "Business Subindex"
+        self.business_subindex.slug = "business-subindex"
+        self.business_index.add_child(instance=self.business_subindex)
+
         # Login
         self.login()
 
@@ -754,3 +760,8 @@ class TestSubpageBusinessRules(TestCase, WagtailTestUtils):
         # but we can add a BusinessChild to BusinessIndex
         response = self.client.get(reverse('wagtailadmin_pages_create', args=('tests', 'businesschild', self.business_index.id)))
         self.assertEqual(response.status_code, 200)
+
+    def test_not_prompted_for_page_type_when_only_one_choice(self):
+        response = self.client.get(reverse('wagtailadmin_pages_add_subpage', args=(self.business_subindex.id, )))
+        # BusinessChild is the only valid subpage type of BusinessSubIndex, so redirect straight there
+        self.assertRedirects(response, reverse('wagtailadmin_pages_create', args=('tests', 'businesschild', self.business_subindex.id)))

wagtail/wagtailadmin/views/pages.py

@@ -59,6 +59,12 @@ def add_subpage(request, parent_page_id):
 
     page_types = sorted(parent_page.clean_subpage_types(), key=lambda pagetype: pagetype.name.lower())
 
+    if len(page_types) == 1:
+        # Only one page type is available - redirect straight to the create form rather than
+        # making the user choose
+        content_type = page_types[0]
+        return redirect('wagtailadmin_pages_create', content_type.app_label, content_type.model, parent_page.id)
+
     return render(request, 'wagtailadmin/pages/add_subpage.html', {
         'parent_page': parent_page,
         'page_types': page_types,