Additional fixes and expansions on field dependencies. Still a WIP.

crudkit/core/base.py

@@ -1,8 +1,21 @@
-from sqlalchemy import Column, Integer, DateTime, Boolean, String, JSON, func
-from sqlalchemy.orm import declarative_mixin, declarative_base
+from sqlalchemy import Column, Integer, DateTime, Boolean, String, JSON, func, inspect
+from sqlalchemy.orm import declarative_mixin, declarative_base, NO_VALUE
 
 Base = declarative_base()
 
+def _safe_get_loaded_attr(obj, name):
+    try:
+        st = inspect(obj)
+        attr = st.attrs.get(name)
+        if attr is not None:
+            val = attr.loaded_value
+            return None if val is NO_VALUE else val
+        if name in st.dict:
+            return st.dict.get(name)
+        return None
+    except Exception:
+        return None
+
 @declarative_mixin
 class CRUDMixin:
     id = Column(Integer, primary_key=True)