Fix datings M2M history

1 files changed, 9 insertions, 3 deletions

diff --git a/archaeological_context_records/models.py b/archaeological_context_records/models.py
index cc4e22cd5..5ba631dba 100644
--- a/archaeological_context_records/models.py
+++ b/archaeological_context_records/models.py
@@ -110,11 +110,17 @@ class Dating(models.Model):
         res = {}
         for idx, val in enumerate(value.split(cls.SEP)):
             key = cls.HISTORY_ATTR[idx]
-            if key in ("period", "dating_type", "quality"):
+            if val == '':
+                val = None
+            elif key in ("period", "dating_type", "quality"):
                 field = cls._meta.get_field(key)
-                val = field.to.model.objects.get(txt_idx=val)
+                q = field.related_model.objects.filter(txt_idx=val)
+                if q.count():
+                    val = q.all()[0]
+                else:  # do not exist anymore in db
+                    val = None
             elif key in ("start_date", "end_date"):
-                val = datetime.datetime.fromisoformat(val)
+                val = int(val)
             res[key] = val
         return res