Add can_choose_root flag to AdminPageChooser widget

Also enable it in the relevant places: permission chooser, and selecting destination for copy page

wagtail/wagtailadmin/forms.py

@@ -116,7 +116,7 @@ class CopyForm(forms.Form):
         self.fields['new_parent_page'] = forms.ModelChoiceField(
             initial=self.page.get_parent(),
             queryset=Page.objects.all(),
-            widget=AdminPageChooser(),
+            widget=AdminPageChooser(can_choose_root=True),
             label=_("New parent page"),
             help_text=_("This copy will be a child of this given parent page.")
         )

wagtail/wagtailadmin/tests/test_widgets.py

@@ -66,3 +66,9 @@ class TestAdminPageChooserWidget(TestCase):
 
         js_init = widget.render_js_init('test-id', 'test', None)
         self.assertEqual(js_init, "createPageChooser(\"test-id\", [\"tests.simplepage\", \"tests.eventpage\"], null, false);")
+
+    def test_render_js_init_with_can_choose_root(self):
+        widget = widgets.AdminPageChooser(can_choose_root=True)
+
+        js_init = widget.render_js_init('test-id', 'test', self.child_page)
+        self.assertEqual(js_init, "createPageChooser(\"test-id\", [\"wagtailcore.page\"], %d, true);" % self.root_page.id)

wagtail/wagtailadmin/widgets.py

@@ -122,9 +122,10 @@ class AdminPageChooser(AdminChooser):
     choose_another_text = _('Choose another page')
     link_to_chosen_text = _('Edit this page')
 
-    def __init__(self, content_type=None, **kwargs):
+    def __init__(self, content_type=None, can_choose_root=False, **kwargs):
         super(AdminPageChooser, self).__init__(**kwargs)
         self._content_type = content_type
+        self.can_choose_root = can_choose_root
 
     @cached_property
     def target_content_types(self):
@@ -166,7 +167,7 @@ class AdminPageChooser(AdminChooser):
 
         parent = page.get_parent() if page else None
 
-        return "createPageChooser({id}, {content_type}, {parent}, false);".format(
+        return "createPageChooser({id}, {content_type}, {parent}, {can_choose_root});".format(
             id=json.dumps(id_),
             content_type=json.dumps([
                 '{app}.{model}'.format(
@@ -174,4 +175,6 @@ class AdminPageChooser(AdminChooser):
                     model=content_type.model)
                 for content_type in self.target_content_types
             ]),
-            parent=json.dumps(parent.id if parent else None))
+            parent=json.dumps(parent.id if parent else None),
+            can_choose_root=('true' if self.can_choose_root else 'false')
+        )

wagtail/wagtailusers/forms.py

@@ -235,7 +235,7 @@ class GroupForm(forms.ModelForm):
 
 class GroupPagePermissionForm(forms.ModelForm):
     page = forms.ModelChoiceField(queryset=Page.objects.all(),
-        widget=AdminPageChooser(show_edit_link=False))
+        widget=AdminPageChooser(show_edit_link=False, can_choose_root=True))
 
     class Meta:
         model = GroupPagePermission