feat: implement scalar type checker

rdfproxy/utils/mapper_utils.py

@@ -15,6 +15,10 @@ def _is_list_type(obj: type | None) -> bool:
     return _is_type(obj, list)
 
 
+def _is_scalar_type(t) -> bool:
+    return (not _is_list_type(t)) and (not issubclass(t, BaseModel))
+
+
 def _is_list_basemodel_type(obj: type | None) -> bool:
     """Check if a type is list[pydantic.BaseModel]."""
     return (get_origin(obj) is list) and all(

rdfproxy/utils/models.py

@@ -6,6 +6,7 @@
 from pydantic import BaseModel, Field, model_validator
 from pydantic.fields import FieldInfo
 from rdfproxy.utils._types import _TModelInstance
+from rdfproxy.utils.mapper_utils import _is_scalar_type
 
 
 class Page(BaseModel, Generic[_TModelInstance]):
@@ -54,7 +55,7 @@ def __class_getitem__(cls, model: type[_TModelInstance]):
         _order_by_fields = [
             (k, auto())
             for k, v in model.model_fields.items()
-            if get_origin(v.annotation) is not list
+            if _is_scalar_type(v.annotation)
         ]
 
         OrderByEnum = StrEnum("OrderByEnum", _order_by_fields)