From c8584cbd3d3faf731f9b9da8875cea7ce64f3187 Mon Sep 17 00:00:00 2001
From: Peter Chang <peter.chang@diamond.ac.uk>
Date: Mon, 6 Jul 2026 14:08:03 +0100
Subject: [PATCH] Reduce logging of validation errors from unpacking messages

Only report errors when every model in union fails validation. Also
fix typing glitch in simple demo script
---
 server/davidia/server/fastapi_utils.py | 9 +++++----
 server/demos/simple.py                 | 8 +++++---
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/server/davidia/server/fastapi_utils.py b/server/davidia/server/fastapi_utils.py
index 93a73cee..8ffde5f0 100644
--- a/server/davidia/server/fastapi_utils.py
+++ b/server/davidia/server/fastapi_utils.py
@@ -148,14 +148,15 @@ async def root_request(payload: MyModel) -> OtherModel:
 
     def _instantiate_obj(model_class, obj):
         if isinstance(model_class, UnionType):
+            excs = {}
             for m in get_args(model_class):
                 try:
                     return m.model_validate(obj)
-                except ValidationError:
-                    logger.warning(
-                        "Could not validate as %s: %s", m, obj, exc_info=True
-                    )
+                except ValidationError as e:
+                    excs[m] = e
             logger.error("No valid models for", obj)
+            for m,e in excs.items():
+                logger.error("%s: %s", m, e)
             return None
 
         if isinstance(obj, BaseModel):
diff --git a/server/demos/simple.py b/server/demos/simple.py
index 73394a0e..6853c381 100644
--- a/server/demos/simple.py
+++ b/server/demos/simple.py
@@ -1,3 +1,4 @@
+from davidia.models.selections import AnySelection
 from time import sleep
 
 import numpy as np
@@ -179,8 +180,7 @@ def table_demo(p):
 
 
 def regions_demo(p):
-    region(
-        selections=[
+    selections: list[AnySelection] = [
             RectangularSelection(
                 start=(3.5, 6.5),
                 lengths=(3.2, 2.0),
@@ -191,7 +191,9 @@ def regions_demo(p):
             LinearSelection(
                 start=(6.9, 10.5), length=2.0, angle=1.1, colour="cyan", alpha=0.6
             ),
-        ],
+        ]
+    region(
+        selections=selections,
         plot_id=f"plot_{p}",
     )
     rs = region(plot_id=f"plot_{p}")