Feat: Adding the option of importing interfaces from strings

grapple/actions.py

@@ -9,6 +9,7 @@
 from django.apps import apps
 from django.core.exceptions import FieldDoesNotExist
 from django.db import models
+from django.utils.module_loading import import_string
 from graphene_django.types import DjangoObjectType
 from wagtail.blocks import StructValue, stream_block
 from wagtail.contrib.settings.models import BaseGenericSetting, BaseSiteSetting
@@ -268,7 +269,12 @@ class StubMeta:
         model = stub_model
 
     # Gather any interfaces, and discard None values
-    interfaces = {interface, *getattr(cls, "graphql_interfaces", ())}
+    interface_classes = getattr(cls, "graphql_interfaces", ())
+    interface_classes = tuple(
+        import_string(i) if isinstance(i, str) else i for i in interface_classes
+    )
+
+    interfaces = {interface, *interface_classes}
     interfaces.discard(None)
 
     type_meta = {

tests/test_interfaces.py

@@ -106,6 +106,13 @@ def test_schema_for_django_model_with_graphql_interfaces(self):
             [{"name": "AdditionalInterface"}],
         )
 
+    def test_imports_graphql_interfaces_defined_by_str(self):
+        results = self.introspect_schema_by_type("SimpleModelWithAlternativeInterface")
+        self.assertListEqual(
+            sorted(results["data"]["__type"]["interfaces"], key=lambda x: x["name"]),
+            [{"name": "AdditionalInterface"}, {"name": "AlternativeInterface"}],
+        )
+
 
 @tag("needs-custom-settings")
 @skipUnless(

tests/testapp/interfaces.py

@@ -7,6 +7,10 @@ class AdditionalInterface(graphene.Interface):
     additional_text = graphene.String()
 
 
+class AlternativeInterface(graphene.Interface):
+    alternative_text = graphene.String()
+
+
 class CustomPageInterface(PageInterface):
     custom_text = graphene.String()
 

tests/testapp/migrations/0003_simplemodelwithalternativeinterface.py

@@ -0,0 +1,26 @@
+# Generated by Django 5.0.14 on 2025-09-28 19:32
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("testapp", "0002_create_homepage"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="SimpleModelWithAlternativeInterface",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+            ],
+        ),
+    ]

tests/testapp/models/core.py

@@ -53,6 +53,14 @@ class SimpleModel(models.Model):
     graphql_interfaces = (AdditionalInterface,)
 
 
+@register_singular_query_field("simpleModelWithAlternativeInterface")
+class SimpleModelWithAlternativeInterface(models.Model):
+    graphql_interfaces = (
+        AdditionalInterface,
+        "testapp.interfaces.AlternativeInterface",
+    )
+
+
 def custom_middleware_one(next, root, info, **args):
     info.context.custom_middleware_one = True
     return next(root, info, **args)