Allow further customization by letting the type resolve itself

docs/guide/pagination.md

@@ -235,6 +235,8 @@ The following attributes/methods can be accessed in the `OffsetPaginated` class:
 - `pagination`: The `OffsetPaginationInput` object, with the `offset` and `limit` for pagination
 - `get_total_count()`: Returns the total count of elements in the queryset without pagination
 - `get_paginated_queryset()`: Returns the queryset with pagination applied
+- `resolve_paginated(queryset, *, info, pagiantion, **kwargs)`: The classmethod that
+  strawberry-django calls to create an instance of the `OffsetPaginated` class/subclass.
 
 ## Cursor pagination (aka Relay style pagination)
 

strawberry_django/pagination.py

@@ -59,6 +59,32 @@ def results(self) -> list[NodeType]:
             list[NodeType], paginated_queryset if paginated_queryset is not None else []
         )
 
+    @classmethod
+    def resolve_paginated(
+        cls,
+        queryset: QuerySet,
+        *,
+        info: Info,
+        pagination: Optional[OffsetPaginationInput] = None,
+        **kwargs,
+    ) -> Self:
+        """Resolve the paginated queryset.
+
+        Args:
+            queryset: The queryset to be paginated.
+            info: The strawberry execution info resolve the type name from.
+            pagination: The pagination input to be applied.
+            kwargs: Additional arguments passed to the resolver.
+
+        Returns:
+            The resolved `OffsetPaginated`
+
+        """
+        return cls(
+            queryset=queryset,
+            pagination=pagination or OffsetPaginationInput(),
+        )
+
     def get_total_count(self) -> int:
         """Retrieve tht total count of the queryset without pagination."""
         return get_total_count(self.queryset) if self.queryset is not None else 0
@@ -294,7 +320,7 @@ def get_queryset(
         queryset: _QS,
         info: Info,
         *,
-        pagination: Optional[object] = None,
+        pagination: Optional[OffsetPaginationInput] = None,
         _strawberry_related_field_id: Optional[str] = None,
         **kwargs,
     ) -> _QS:
@@ -318,7 +344,7 @@ def get_wrapped_result(
         result: _T,
         info: Info,
         *,
-        pagination: Optional[object] = None,
+        pagination: Optional[OffsetPaginationInput] = None,
         **kwargs,
     ) -> Union[_T, OffsetPaginated[_T]]:
         if not self.is_paginated:
@@ -333,7 +359,13 @@ def get_wrapped_result(
         ):
             raise TypeError(f"Don't know how to resolve pagination {pagination!r}")
 
-        return OffsetPaginated(
-            queryset=result,
-            pagination=pagination or OffsetPaginationInput(),
+        paginated_type = self.type
+        assert isinstance(paginated_type, type)
+        assert issubclass(paginated_type, OffsetPaginated)
+
+        return paginated_type.resolve_paginated(
+            result,
+            info=info,
+            pagination=pagination,
+            **kwargs,
         )

tests/test_paginated_type.py

@@ -4,7 +4,7 @@
 import strawberry
 
 import strawberry_django
-from strawberry_django.pagination import OffsetPaginated
+from strawberry_django.pagination import OffsetPaginated, OffsetPaginationInput
 from tests import models
 
 
@@ -414,3 +414,81 @@ class Query:
             ],
         }
     }
+
+
+@pytest.mark.django_db(transaction=True)
+def test_pagination_query_with_subclass():
+    @strawberry_django.type(models.Fruit)
+    class Fruit:
+        id: int
+        name: str
+
+    @strawberry.type
+    class FruitPaginated(OffsetPaginated[Fruit]):
+        _custom_field: strawberry.Private[str]
+
+        @strawberry_django.field
+        def custom_field(self) -> str:
+            return self._custom_field
+
+        @classmethod
+        def resolve_paginated(cls, queryset, *, info, pagination=None, **kwargs):
+            return cls(
+                queryset=queryset,
+                pagination=pagination or OffsetPaginationInput(),
+                _custom_field="pagination rocks",
+            )
+
+    @strawberry.type
+    class Query:
+        fruits: FruitPaginated = strawberry_django.field()
+
+    models.Fruit.objects.create(name="Apple")
+    models.Fruit.objects.create(name="Banana")
+    models.Fruit.objects.create(name="Strawberry")
+
+    schema = strawberry.Schema(query=Query)
+
+    query = """\
+    query GetFruits ($pagination: OffsetPaginationInput) {
+      fruits (pagination: $pagination) {
+        totalCount
+        customField
+        results {
+          name
+        }
+      }
+    }
+    """
+
+    res = schema.execute_sync(query)
+    assert res.errors is None
+    assert res.data == {
+        "fruits": {
+            "totalCount": 3,
+            "customField": "pagination rocks",
+            "results": [{"name": "Apple"}, {"name": "Banana"}, {"name": "Strawberry"}],
+        }
+    }
+
+    res = schema.execute_sync(query, variable_values={"pagination": {"limit": 1}})
+    assert res.errors is None
+    assert res.data == {
+        "fruits": {
+            "totalCount": 3,
+            "customField": "pagination rocks",
+            "results": [{"name": "Apple"}],
+        }
+    }
+
+    res = schema.execute_sync(
+        query, variable_values={"pagination": {"limit": 1, "offset": 2}}
+    )
+    assert res.errors is None
+    assert res.data == {
+        "fruits": {
+            "totalCount": 3,
+            "customField": "pagination rocks",
+            "results": [{"name": "Strawberry"}],
+        }
+    }