Defer validation of min_num constraints on InlinePanel when saving drafts

wagtail/admin/forms/models.py

@@ -135,10 +135,11 @@ class WagtailAdminModelForm(
         # keep hold of the `for_user` kwarg as well as passing it on to PermissionedForm
         self.for_user = kwargs.get("for_user")
         self.deferred_required_fields = []
+        self.deferred_formset_min_nums = {}
         super().__init__(*args, **kwargs)
 
     def defer_required_fields(self):
-        if self.deferred_required_fields:
+        if self.deferred_required_fields or self.deferred_formset_min_nums:
             # defer_required_fields has already been called
             return
 
@@ -150,14 +151,20 @@ class WagtailAdminModelForm(
             except KeyError:
                 pass
 
-        for formset in self.formsets.values():
+        for name, formset in self.formsets.items():
             for form in formset:
                 form.defer_required_fields()
+            if formset.min_num is not None:
+                self.deferred_formset_min_nums[name] = formset.min_num
+                formset.min_num = 0
 
     def restore_required_fields(self):
-        for formset in self.formsets.values():
+        for name, formset in self.formsets.items():
             for form in formset:
                 form.restore_required_fields()
+            if name in self.deferred_formset_min_nums:
+                formset.min_num = self.deferred_formset_min_nums[name]
+        self.deferred_formset_min_nums = {}
 
         for field_name in self.deferred_required_fields:
             self.fields[field_name].required = True

wagtail/admin/tests/pages/test_create_page.py

@@ -18,6 +18,7 @@ from wagtail.models import (
 )
 from wagtail.signals import page_published
 from wagtail.test.testapp.models import (
+    Advert,
     BusinessChild,
     BusinessIndex,
     BusinessSubIndex,
@@ -903,6 +904,89 @@ class TestPageCreation(WagtailTestUtils, TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertContains(response, "This field is required.")
 
+    def test_can_create_page_with_less_than_min_inline_panels(self):
+        # min_num constraints on inline panels should not be enforced when saving as draft
+        post_data = nested_form_data(
+            {
+                "title": "Promotional page",
+                "slug": "promotional-page",
+                "advert_placements": inline_formset([]),
+            }
+        )
+        response = self.client.post(
+            reverse(
+                "wagtailadmin_pages:add",
+                args=("tests", "promotionalpage", self.root_page.id),
+            ),
+            post_data,
+        )
+        # Find the page and check it
+        page = Page.objects.get(
+            path__startswith=self.root_page.path, slug="promotional-page"
+        ).specific
+
+        # Should be redirected to edit page
+        self.assertRedirects(
+            response, reverse("wagtailadmin_pages:edit", args=(page.id,))
+        )
+
+        self.assertEqual(page.advert_placements.count(), 0)
+        self.assertFalse(page.live)
+
+    def test_cannot_publish_page_with_less_than_min_inline_panels(self):
+        # min_num constraints on inline panels should not be enforced when saving as draft
+        post_data = nested_form_data(
+            {
+                "title": "Promotional page",
+                "slug": "promotional-page",
+                "advert_placements": inline_formset([]),
+                "action-publish": "Publish",
+            }
+        )
+        response = self.client.post(
+            reverse(
+                "wagtailadmin_pages:add",
+                args=("tests", "promotionalpage", self.root_page.id),
+            ),
+            post_data,
+        )
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, "Please submit at least 1 form.")
+
+    def test_can_publish_page_with_enough_inline_panels(self):
+        advert = Advert.objects.create(text="Red Bull gives you wings")
+        # min_num constraints on inline panels should not be enforced when saving as draft
+        post_data = nested_form_data(
+            {
+                "title": "Promotional page",
+                "slug": "promotional-page",
+                "advert_placements": inline_formset(
+                    [
+                        {
+                            "advert": advert.id,
+                            "colour": "red",
+                        },
+                    ]
+                ),
+                "action-publish": "Publish",
+            }
+        )
+        response = self.client.post(
+            reverse(
+                "wagtailadmin_pages:add",
+                args=("tests", "promotionalpage", self.root_page.id),
+            ),
+            post_data,
+        )
+        self.assertRedirects(
+            response, reverse("wagtailadmin_explore", args=(self.root_page.id,))
+        )
+        page = Page.objects.get(
+            path__startswith=self.root_page.path, slug="promotional-page"
+        ).specific
+        self.assertTrue(page.live)
+        self.assertEqual(page.advert_placements.count(), 1)
+
     def test_create_simplepage_scheduled(self):
         go_live_at = timezone.now() + datetime.timedelta(days=1)
         expire_at = timezone.now() + datetime.timedelta(days=2)

wagtail/test/testapp/migrations/0049_promotionalpage.py

@@ -0,0 +1,35 @@
+# Generated by Django 5.0.12 on 2025-03-20 22:31
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("tests", "0048_requireddatepage"),
+        ("wagtailcore", "0094_alter_page_locale"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="PromotionalPage",
+            fields=[
+                (
+                    "page_ptr",
+                    models.OneToOneField(
+                        auto_created=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        parent_link=True,
+                        primary_key=True,
+                        serialize=False,
+                        to="wagtailcore.page",
+                    ),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+            bases=("wagtailcore.page",),
+        ),
+    ]

wagtail/test/testapp/models.py

@@ -1396,6 +1396,12 @@ class StandardIndex(Page):
     promote_panels = []
 
 
+class PromotionalPage(Page):
+    content_panels = Page.content_panels + [
+        InlinePanel("advert_placements", label="Adverts", min_num=1),
+    ]
+
+
 class StandardChild(Page):
     pass