Make image upload forms use the correct widget for custom tag models

wagtail/images/forms.py

@@ -4,12 +4,12 @@ from django.forms.models import modelform_factory
 from django.utils.text import capfirst
 from django.utils.translation import gettext as _
 
-from wagtail.admin import widgets
 from wagtail.admin.forms.collections import (
     BaseCollectionMemberForm,
     CollectionChoiceField,
     collection_member_permission_formset_factory,
 )
+from wagtail.admin.widgets import AdminTagWidget
 from wagtail.images.fields import WagtailImageField
 from wagtail.images.formats import get_image_formats
 from wagtail.images.models import Image
@@ -42,7 +42,7 @@ class BaseImageForm(BaseCollectionMemberForm):
         # so that when editing, we don't get the 'currently: ...' banner which is
         # a bit pointless here
         widgets = {
-            "tags": widgets.AdminTagWidget,
+            "tags": AdminTagWidget,
             "file": forms.FileInput(),
             "focal_point_x": forms.HiddenInput(attrs={"class": "focal_point_x"}),
             "focal_point_y": forms.HiddenInput(attrs={"class": "focal_point_y"}),
@@ -75,10 +75,23 @@ def get_image_form(model):
         # and when only one collection exists, it will get hidden anyway.
         fields = list(fields) + ["collection"]
 
+    BaseForm = get_image_base_form()
+
+    # If the base form specifies the 'tags' widget as a plain unconfigured AdminTagWidget,
+    # substitute one that correctly passes the tag model used on the image model.
+    # (If the widget has been overridden via WAGTAILIMAGES_IMAGE_FORM_BASE, leave it
+    # alone and trust that they know what they're doing)
+    widgets = None
+    if BaseForm._meta.widgets.get("tags") == AdminTagWidget:
+        tag_model = model._meta.get_field("tags").related_model
+        widgets = BaseForm._meta.widgets.copy()
+        widgets["tags"] = AdminTagWidget(tag_model=tag_model)
+
     return modelform_factory(
         model,
-        form=get_image_base_form(),
+        form=BaseForm,
         fields=fields,
+        widgets=widgets,
         formfield_callback=formfield_for_dbfield,
     )
 

wagtail/images/tests/test_form_overrides.py

@@ -1,11 +1,13 @@
 from django import forms
 from django.test import TestCase, override_settings
+from taggit import models as taggit_models
 
 from wagtail.admin import widgets
 from wagtail.admin.widgets import AdminDateTimeInput
 from wagtail.images import models
 from wagtail.images.forms import BaseImageForm, get_image_base_form, get_image_form
 from wagtail.test.testapp.media_forms import AlternateImageForm, OverriddenWidget
+from wagtail.test.testapp.models import CustomRestaurantImage, RestaurantTag
 
 
 class TestImageFormOverride(TestCase):
@@ -21,9 +23,16 @@ class TestImageFormOverride(TestCase):
         form_cls = get_image_form(models.Image)
         form = form_cls()
         self.assertIsInstance(form.fields["tags"].widget, widgets.AdminTagWidget)
+        self.assertEqual(form.fields["tags"].widget.tag_model, taggit_models.Tag)
         self.assertIsInstance(form.fields["file"].widget, forms.FileInput)
         self.assertIsInstance(form.fields["focal_point_x"].widget, forms.HiddenInput)
 
+    def test_tags_widget_with_custom_tag_model(self):
+        form_cls = get_image_form(CustomRestaurantImage)
+        form = form_cls()
+        self.assertIsInstance(form.fields["tags"].widget, widgets.AdminTagWidget)
+        self.assertEqual(form.fields["tags"].widget.tag_model, RestaurantTag)
+
     @override_settings(
         WAGTAILIMAGES_IMAGE_FORM_BASE="wagtail.test.testapp.media_forms.AlternateImageForm"
     )

wagtail/test/testapp/migrations/0065_tagged_restaurant_image.py

@@ -0,0 +1,142 @@
+# Generated by Django 3.2.11 on 2022-01-27 16:23
+
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+import taggit.managers
+import wagtail.core.models.collections
+import wagtail.images.models
+import wagtail.search.index
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("wagtailcore", "0066_collection_management_permissions"),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ("tests", "0064_tagged_restaurant_document"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="CustomRestaurantImage",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("title", models.CharField(max_length=255, verbose_name="title")),
+                (
+                    "file",
+                    models.ImageField(
+                        height_field="height",
+                        upload_to=wagtail.images.models.get_upload_to,
+                        verbose_name="file",
+                        width_field="width",
+                    ),
+                ),
+                ("width", models.IntegerField(editable=False, verbose_name="width")),
+                ("height", models.IntegerField(editable=False, verbose_name="height")),
+                (
+                    "created_at",
+                    models.DateTimeField(
+                        auto_now_add=True, db_index=True, verbose_name="created at"
+                    ),
+                ),
+                ("focal_point_x", models.PositiveIntegerField(blank=True, null=True)),
+                ("focal_point_y", models.PositiveIntegerField(blank=True, null=True)),
+                (
+                    "focal_point_width",
+                    models.PositiveIntegerField(blank=True, null=True),
+                ),
+                (
+                    "focal_point_height",
+                    models.PositiveIntegerField(blank=True, null=True),
+                ),
+                ("file_size", models.PositiveIntegerField(editable=False, null=True)),
+                (
+                    "file_hash",
+                    models.CharField(blank=True, editable=False, max_length=40),
+                ),
+                (
+                    "collection",
+                    models.ForeignKey(
+                        default=wagtail.core.models.collections.get_root_collection_id,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="+",
+                        to="wagtailcore.collection",
+                        verbose_name="collection",
+                    ),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+            bases=(
+                wagtail.images.models.ImageFileMixin,
+                wagtail.search.index.Indexed,
+                models.Model,
+            ),
+        ),
+        migrations.CreateModel(
+            name="TaggedRestaurantImage",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                (
+                    "content_object",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="tagged_items",
+                        to="tests.customrestaurantimage",
+                    ),
+                ),
+                (
+                    "tag",
+                    models.ForeignKey(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name="tagged_images",
+                        to="tests.restauranttag",
+                    ),
+                ),
+            ],
+            options={
+                "abstract": False,
+            },
+        ),
+        migrations.AddField(
+            model_name="customrestaurantimage",
+            name="tags",
+            field=taggit.managers.TaggableManager(
+                blank=True,
+                help_text=None,
+                through="tests.TaggedRestaurantImage",
+                to="tests.RestaurantTag",
+                verbose_name="tags",
+            ),
+        ),
+        migrations.AddField(
+            model_name="customrestaurantimage",
+            name="uploaded_by_user",
+            field=models.ForeignKey(
+                blank=True,
+                editable=False,
+                null=True,
+                on_delete=django.db.models.deletion.SET_NULL,
+                to=settings.AUTH_USER_MODEL,
+                verbose_name="uploaded by user",
+            ),
+        ),
+    ]

wagtail/test/testapp/models.py

@@ -1734,3 +1734,22 @@ class CustomRestaurantDocument(AbstractDocument):
         through=TaggedRestaurantDocument,
     )
     admin_form_fields = Document.admin_form_fields
+
+
+# Custom image model with a custom tag field
+class TaggedRestaurantImage(ItemBase):
+    tag = models.ForeignKey(
+        RestaurantTag, related_name="tagged_images", on_delete=models.CASCADE
+    )
+    content_object = models.ForeignKey(
+        to="tests.CustomRestaurantImage",
+        on_delete=models.CASCADE,
+        related_name="tagged_items",
+    )
+
+
+class CustomRestaurantImage(AbstractImage):
+    tags = TaggableManager(
+        help_text=None, blank=True, verbose_name="tags", through=TaggedRestaurantImage
+    )
+    admin_form_fields = Image.admin_form_fields