Implement register_group_permission_panel hook for adding new panels to the group edit form

docs/reference/hooks.rst

@@ -145,6 +145,14 @@ Hooks for building new areas of the admin interface (alongside pages, images, do
       ]
 
 
+.. _register_group_permission_panel:
+
+``register_group_permission_panel``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+  Add a new panel to the Groups form in the 'settings' area. The callable passed to this hook must return a ModelForm / ModelFormSet-like class, with a constructor that accepts a group object as its ``instance`` keyword argument, and which implements the methods ``save``, ``is_valid``, and ``as_admin_panel`` (which returns the HTML to be included on the group edit page).
+
+
 .. _register_settings_menu_item:
 
 ``register_settings_menu_item``

wagtail/wagtailusers/forms.py

@@ -5,6 +5,7 @@ from django.db import transaction
 from django.contrib.auth import get_user_model
 from django.utils.translation import ugettext_lazy as _
 from django.contrib.auth.models import Group, Permission
+from django.template.loader import render_to_string
 
 from wagtail.wagtailcore import hooks
 from wagtail.wagtailadmin.widgets import AdminPageChooser
@@ -336,6 +337,11 @@ class BaseGroupPagePermissionFormSet(forms.BaseFormSet):
             for (page, permission_type) in permissions_to_add
         ])
 
+    def as_admin_panel(self):
+        return render_to_string('wagtailusers/groups/includes/page_permissions_formset.html', {
+            'formset': self
+        })
+
 
 GroupPagePermissionFormSet = forms.formset_factory(
     PagePermissionsForm, formset=BaseGroupPagePermissionFormSet, extra=0, can_delete=True

wagtail/wagtailusers/templates/wagtailusers/groups/create.html

@@ -23,9 +23,11 @@
                 <li>
                     {% format_permissions permission_bound_field=form.permissions %}
                 </li>
-                <li>
-                    {% include "wagtailusers/groups/includes/page_permissions_formset.html" with formset=formset only %}
-                </li>
+                {% for panel in permission_panels %}
+                    <li>
+                        {{ panel.as_admin_panel }}
+                    </li>
+                {% endfor %}
                 <li><input type="submit" value='{% trans "Add group" %}' /></li>
             </ul>
         </form>

wagtail/wagtailusers/templates/wagtailusers/groups/edit.html

@@ -24,9 +24,11 @@
                 <li>
                     {% format_permissions permission_bound_field=form.permissions %}
                 </li>
-                <li>
-                    {% include "wagtailusers/groups/includes/page_permissions_formset.html" with formset=formset only %}
-                </li>
+                {% for panel in permission_panels %}
+                    <li>
+                        {{ panel.as_admin_panel }}
+                    </li>
+                {% endfor %}
                 <li>
                     <input type="submit" value="{% trans 'Save' %}" />
 

wagtail/wagtailusers/views/groups.py

@@ -5,12 +5,26 @@ from django.utils.translation import ugettext as _
 from django.views.decorators.vary import vary_on_headers
 
 from wagtail.utils.pagination import paginate
+from wagtail.wagtailcore import hooks
 from wagtail.wagtailadmin import messages
 from wagtail.wagtailadmin.forms import SearchForm
 from wagtail.wagtailadmin.utils import permission_required, any_permission_required
 from wagtail.wagtailusers.forms import GroupForm, GroupPagePermissionFormSet
 
 
+_permission_panel_classes = None
+
+
+def get_permission_panel_classes():
+    global _permission_panel_classes
+    if _permission_panel_classes is None:
+        _permission_panel_classes = [GroupPagePermissionFormSet]
+        for fn in hooks.get_hooks('register_group_permission_panel'):
+            _permission_panel_classes.append(fn())
+
+    return _permission_panel_classes
+
+
 @any_permission_required('auth.add_group', 'auth.change_group', 'auth.delete_group')
 @vary_on_headers('X-Requested-With')
 def index(request):
@@ -65,10 +79,16 @@ def create(request):
     group = Group()
     if request.POST:
         form = GroupForm(request.POST, instance=group)
-        formset = GroupPagePermissionFormSet(request.POST, instance=group)
-        if form.is_valid() and formset.is_valid():
+        permission_panels = [
+            cls(request.POST, instance=group)
+            for cls in get_permission_panel_classes()
+        ]
+        if form.is_valid() and all(panel.is_valid() for panel in permission_panels):
             form.save()
-            formset.save()
+
+            for panel in permission_panels:
+                panel.save()
+
             messages.success(request, _("Group '{0}' created.").format(group), buttons=[
                 messages.button(reverse('wagtailusers_groups:edit', args=(group.id,)), _('Edit'))
             ])
@@ -77,11 +97,14 @@ def create(request):
             messages.error(request, _("The group could not be created due to errors."))
     else:
         form = GroupForm(instance=group)
-        formset = GroupPagePermissionFormSet(instance=group)
+        permission_panels = [
+            cls(instance=group)
+            for cls in get_permission_panel_classes()
+        ]
 
     return render(request, 'wagtailusers/groups/create.html', {
         'form': form,
-        'formset': formset,
+        'permission_panels': permission_panels,
     })
 
 
@@ -90,10 +113,16 @@ def edit(request, group_id):
     group = get_object_or_404(Group, id=group_id)
     if request.POST:
         form = GroupForm(request.POST, instance=group)
-        formset = GroupPagePermissionFormSet(request.POST, instance=group)
-        if form.is_valid() and formset.is_valid():
+        permission_panels = [
+            cls(request.POST, instance=group)
+            for cls in get_permission_panel_classes()
+        ]
+        if form.is_valid() and all(panel.is_valid() for panel in permission_panels):
             form.save()
-            formset.save()
+
+            for panel in permission_panels:
+                panel.save()
+
             messages.success(request, _("Group '{0}' updated.").format(group), buttons=[
                 messages.button(reverse('wagtailusers_groups:edit', args=(group.id,)), _('Edit'))
             ])
@@ -102,12 +131,15 @@ def edit(request, group_id):
             messages.error(request, _("The group could not be saved due to errors."))
     else:
         form = GroupForm(instance=group)
-        formset = GroupPagePermissionFormSet(instance=group)
+        permission_panels = [
+            cls(instance=group)
+            for cls in get_permission_panel_classes()
+        ]
 
     return render(request, 'wagtailusers/groups/edit.html', {
         'group': group,
         'form': form,
-        'formset': formset,
+        'permission_panels': permission_panels,
     })