Fix MgmtForm bug when parent inlines have has_add_perm false & min_num>0

A ManagementForm validation error is thrown when trying to save an admin
containing nested inlines, where a parent inline has a min_num defined
and the user has change permissions but not add permissions.

Author: fdintino

nested_admin/nested.py

@@ -325,21 +325,32 @@ def _create_formsets(self, request, obj, change):
             if hasattr(orig_inline, 'child_inline_instances'):
                 for child_inline in orig_inline.child_inline_instances:
                     nested_formsets_and_inline_instances += [
-                        (orig_formset, inline)
+                        (orig_formset, inline, orig_inline)
                         for inline
                         in child_inline.get_inline_instances(request, obj)]
 
             if getattr(orig_inline, 'inlines', []):
                 nested_formsets_and_inline_instances += [
-                    (orig_formset, inline)
+                    (orig_formset, inline, orig_inline)
                     for inline
                     in orig_inline.get_inline_instances(request, obj)]
 
             i = 0
             while i < len(nested_formsets_and_inline_instances):
-                formset, inline = nested_formsets_and_inline_instances[i]
+                formset, inline, parent_inline = nested_formsets_and_inline_instances[i]
                 i += 1
-                formset_forms = list(formset.forms) + [None]
+
+                try:
+                    has_add_permission = parent_inline.has_add_permission(request, obj)
+                except TypeError:
+                    # Django before 2.2 didn't require obj kwarg
+                    has_add_permission = parent_inline.has_add_permission(request)
+
+                formset_forms = list(formset.forms)
+
+                if has_add_permission:
+                    formset_forms.append(None)
+
                 for form in formset_forms:
                     if form is not None:
                         form.parent_formset = formset
@@ -426,13 +437,13 @@ def user_deleted_form(request, obj, formset, index):
 
                     if hasattr(inline, 'get_inline_instances'):
                         nested_formsets_and_inline_instances += [
-                            (nested_formset, nested_inline)
+                            (nested_formset, nested_inline, inline)
                             for nested_inline
                             in inline.get_inline_instances(request, form_obj)]
                     if hasattr(inline, 'child_inline_instances'):
                         for nested_child in inline.child_inline_instances:
                             nested_formsets_and_inline_instances += [
-                                (nested_formset, nested_inline)
+                                (nested_formset, nested_inline, nested_child)
                                 for nested_inline
                                 in nested_child.get_inline_instances(request, form_obj)]
         return formsets, inline_instances

nested_admin/templates/nesting/admin/inlines/grappelli_stacked.html

@@ -32,7 +32,7 @@ <h2 class="djn-collapse-handler grp-collapse-handler">
                  {% if inline_admin_form.pk_field.field %}
                  data-is-initial="{% if inline_admin_form.pk_field.field.value %}true{% else %}false{% endif %}"
                  {% endif %}
-                 id="{{ inline_admin_formset.formset.prefix }}-{% if forloop.last and inline_admin_formset.has_add_permission %}empty{% elif not forloop.last %}{{ inline_admin_form.form|form_index }}{% endif %}">
+                 id="{{ inline_admin_formset.formset.prefix }}-{% if forloop.last and inline_admin_formset.has_add_permission %}empty{% else %}{{ inline_admin_form.form|form_index }}{% endif %}">
                 <h3 class="djn-collapse-handler grp-collapse-handler{% if not inline_opts.sortable_options or not inline_opts.sortable_options.disabled %} djn-drag-handler{% endif %}">
                     <div class="djn-collapse-handler-verbose-name">{{ inline_admin_formset.opts.verbose_name }}&nbsp;&nbsp;</div>{% if inline_admin_form.original %}{{ inline_admin_form.original|striptags|safe }}{% endif %}
                 </h3>

nested_admin/templates/nesting/admin/inlines/grappelli_tabular.html

@@ -45,7 +45,7 @@ <h2 class="djn-collapse-handler grp-collapse-handler">
                 {% if inline_admin_form.pk_field.field %}
                 data-is-initial="{% if inline_admin_form.pk_field.field.value %}true{% else %}false{% endif %}"
                 {% endif %}
-                id="{{ inline_admin_formset.formset.prefix }}-{% if forloop.last and inline_admin_formset.has_add_permission %}empty{% elif not forloop.last %}{%if is_nested %}{% endif %}{{ inline_admin_form.form|form_index }}{% endif %}">
+                id="{{ inline_admin_formset.formset.prefix }}-{% if forloop.last and inline_admin_formset.has_add_permission %}empty{% else %}{{ inline_admin_form.form|form_index }}{% endif %}">
 
             {% if inline_admin_form.form.non_field_errors %}
             <tr class="grp-tr"><td class="grp-td djn-td" colspan="{{ inline_admin_form|cell_count }}">

nested_admin/templates/nesting/admin/inlines/stacked.html

@@ -28,7 +28,7 @@ <h2>
                  {% if inline_admin_form.pk_field.field %}
                  data-is-initial="{% if inline_admin_form.pk_field.field.value %}true{% else %}false{% endif %}"
                  {% endif %}
-                 id="{{ inline_admin_formset.formset.prefix }}-{% if forloop.last and inline_admin_formset.has_add_permission %}empty{% elif not forloop.last %}{{ inline_admin_form.form|form_index }}{% endif %}">
+                 id="{{ inline_admin_formset.formset.prefix }}-{% if forloop.last and inline_admin_formset.has_add_permission %}empty{% else %}{{ inline_admin_form.form|form_index }}{% endif %}">
 
                 <h3 class="{% if not inline_opts.sortable_options or not inline_opts.sortable_options.disabled %} djn-drag-handler{% endif %}">
                     <b>{{ inline_admin_formset.opts.verbose_name|capfirst }}:</b>&nbsp;<span class="inline_label">{% if inline_admin_form.original %}{{ inline_admin_form.original }}{% if inline_admin_form.model_admin.show_change_link and inline_admin_form.model_admin.has_registered_model %} <a href="{% url inline_admin_form.model_admin.opts|admin_urlname:'change' inline_admin_form.original.pk|admin_urlquote %}" class="{% if inline_admin_formset.has_change_permission %}inlinechangelink{% else %}inlineviewlink{% endif %}">{% if inline_admin_formset.has_change_permission %}{% trans "Change" %}{% else %}{% trans "View" %}{% endif %}</a>{% endif %}

nested_admin/templates/nesting/admin/inlines/tabular.html

@@ -41,7 +41,7 @@ <h2>
                 {% if inline_admin_form.pk_field.field %}
                 data-is-initial="{% if inline_admin_form.pk_field.field.value %}true{% else %}false{% endif %}"
                 {% endif %}
-                id="{{ inline_admin_formset.formset.prefix }}-{% if forloop.last and inline_admin_formset.has_add_permission %}empty{% elif not forloop.last %}{%if is_nested %}{% endif %}{{ inline_admin_form.form|form_index }}{% endif %}">
+                id="{{ inline_admin_formset.formset.prefix }}-{% if forloop.last and inline_admin_formset.has_add_permission %}empty{% else %}{%if is_nested %}{% endif %}{{ inline_admin_form.form|form_index }}{% endif %}">
 
             {% if inline_admin_form.form.non_field_errors %}
             <tr><td class="djn-td" colspan="{{ inline_admin_form|cell_count }}">

nested_admin/tests/mixed_permissions_min_num_bug/__init__.py

@@ -0,0 +1,38 @@
+from django.contrib import admin
+
+from nested_admin import NestedModelAdmin, NestedStackedInline, NestedTabularInline
+
+from .models import CuratedGroupCollection, CuratedGroup, CuratedList, CuratedItem
+
+
+class CuratedItemInline(NestedTabularInline):
+
+    model = CuratedItem
+    sortable_field_name = 'position'
+    extra = 0
+    inline_classes = ['grp-open']
+
+
+class CuratedListInline(NestedStackedInline):
+
+    model = CuratedList
+    sortable_field_name = 'position'
+    inlines = [CuratedItemInline]
+    min_num = 1
+    extra = 0
+    inline_classes = ['grp-open']
+
+
+class CuratedGroupInline(NestedStackedInline):
+
+    inlines = [CuratedListInline]
+    model = CuratedGroup
+    sortable_field_name = 'position'
+    extra = 0
+    inline_classes = ['grp-open']
+
+
+@admin.register(CuratedGroupCollection)
+class CuratedGroupCollection(NestedModelAdmin):
+
+    inlines = [CuratedGroupInline]

nested_admin/tests/mixed_permissions_min_num_bug/admin.py

@@ -0,0 +1,51 @@
+from django.db import models
+from nested_admin.tests.compat import python_2_unicode_compatible
+
+
+@python_2_unicode_compatible
+class CuratedGroupCollection(models.Model):
+    slug = models.SlugField()
+    name = models.CharField(max_length=64)
+
+    def __str__(self):
+        return self.name
+
+
+@python_2_unicode_compatible
+class CuratedGroup(models.Model):
+    slug = models.SlugField()
+    name = models.CharField(max_length=64)
+    collection = models.ForeignKey(CuratedGroupCollection, on_delete=models.CASCADE)
+    position = models.PositiveSmallIntegerField()
+
+    class Meta:
+        ordering = ['position']
+
+    def __str__(self):
+        return self.name
+
+
+class CuratedList(models.Model):
+
+    position = models.PositiveSmallIntegerField()
+    group = models.ForeignKey(CuratedGroup, on_delete=models.CASCADE)
+
+    class Meta:
+        ordering = ['position']
+
+
+@python_2_unicode_compatible
+class CuratedItem(models.Model):
+
+    parent = models.ForeignKey(CuratedList, on_delete=models.CASCADE)
+    position = models.PositiveSmallIntegerField()
+    name = models.CharField(max_length=64, blank=True)
+
+    class Meta:
+        ordering = ['position']
+
+    def __str__(self):
+        if self.name:
+            return self.name
+        else:
+            return "Curated Item"

nested_admin/tests/mixed_permissions_min_num_bug/models.py

@@ -0,0 +1,84 @@
+from unittest import SkipTest
+
+import django
+from django.contrib.auth import get_permission_codename
+from django.contrib.auth.models import Permission, User
+from django.contrib.contenttypes.models import ContentType
+
+from nested_admin.tests.base import BaseNestedAdminTestCase
+from .models import (
+    CuratedGroupCollection,
+    CuratedGroup, CuratedList, CuratedItem)
+
+
+def get_perm(Model, perm):
+    """Return the permission object, for the Model"""
+    ct = ContentType.objects.get_for_model(Model)
+    return Permission.objects.get(content_type=ct, codename=perm)
+
+
+class TestMixedPermissionsMinNumBug(BaseNestedAdminTestCase):
+
+    root_model = CuratedGroupCollection
+    nested_models = (CuratedGroup, CuratedList, CuratedItem)
+
+    auto_login = False
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestMixedPermissionsMinNumBug, cls).setUpClass()
+        cls.models = (cls.root_model,) + tuple(cls.nested_models)
+
+    def setUp(self):
+        super(TestMixedPermissionsMinNumBug, self).setUp()
+        self.collection = CuratedGroupCollection.objects.create(
+            slug='site-nav', name='Site Nav')
+        lists = []
+        for i, group_name in enumerate(('Sections', 'Magazine', 'More')):
+            group = CuratedGroup.objects.create(
+                name=group_name,
+                slug=group_name.lower(),
+                collection=self.collection,
+                position=i)
+            lists.append(
+                CuratedList.objects.create(group=group, position=0))
+
+        section_labels = [
+            ('Politics', 'Culture', 'Podcasts'),
+            ('Current Issue', 'All Issues', 'Subscribe'),
+            ('Newsletters', 'Events'),
+        ]
+
+        for list_obj, sections in zip(lists, section_labels):
+            for i, section in enumerate(sections):
+                CuratedItem.objects.create(
+                    parent=list_obj, position=i, name=section)
+
+        self.user = User.objects.create_user(
+            username='permissionuser', password='secret',
+            email='vuser@example.com', is_staff=True)
+
+        models = (self.root_model,) + tuple(self.nested_models)
+        for model_cls in models:
+            self.user.user_permissions.add(
+                get_perm(model_cls, get_permission_codename('change', model_cls._meta)))
+
+        for model_cls in (CuratedList, CuratedItem):
+            self.user.user_permissions.add(
+                get_perm(model_cls, get_permission_codename('add', model_cls._meta)))
+            self.user.user_permissions.add(
+                get_perm(model_cls, get_permission_codename('delete', model_cls._meta)))
+
+        self.admin_login('permissionuser', 'secret')
+
+    def test_mixed_no_top_level_add_permissions_save(self):
+        self.load_admin(self.collection)
+        self.set_field('name', 'Politics!', [0, 0, 0])
+        self.save_form()
+
+        item = CuratedItem.objects.get(
+            parent__group__position=0,
+            parent__position=0,
+            position=0)
+
+        self.assertEqual(item.name, "Politics!", "Item name did not update")