Apply data migration for templates

src/backend/InvenTree/common/migrations/0041_auto_20251028_1112.py

@@ -0,0 +1,54 @@
+# Generated by Django 4.2.25 on 2025-10-28 11:12
+
+from django.db import migrations
+
+
+def copy_templates(old_model, new_model):
+    """Copy from one model type to another."""
+    
+    templates = []
+
+    for template in old_model.objects.all():
+        templates.append(new_model(
+            name=template.name,
+            description=template.description,
+            units=template.units,
+            checkbox=template.checkbox,
+            choices=template.choices,
+            selectionlist=template.selectionlist,
+        ))
+
+
+    if len(templates) > 0:
+        new_model.objects.bulk_create(templates)
+        print(f"Migrated {len(templates)} ParameterTemplate instances.")
+
+
+def forward_copy_templates(apps, schema_editor):
+    """Forward migration: copy from PartParameterTemplate to ParameterTemplate."""
+    PartParameterTemplate = apps.get_model("part", "PartParameterTemplate")
+    ParameterTemplate = apps.get_model("common", "ParameterTemplate")
+
+    copy_templates(PartParameterTemplate, ParameterTemplate)
+
+
+def reverse_copy_templates(apps, schema_editor):
+    """Reverse migration: copy from ParameterTemplate to PartParameterTemplate."""
+    ParameterTemplate = apps.get_model("common", "ParameterTemplate")
+    PartParameterTemplate = apps.get_model("part", "PartParameterTemplate")
+
+    copy_templates(ParameterTemplate, PartParameterTemplate)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("common", "0040_parametertemplate"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            forward_copy_templates,
+            reverse_code=reverse_copy_templates
+        )
+    ]