Inconsistency with default validators and IS_EMPTY_OR

[nursix]

All default validators are IS_EMPTY_OR unless the field is notnull=True - except for reference types, which never are IS_EMPTY_OR.

This seems odd - why do reference types require a value by default, but all other field types do not? Any good reason for that? Or is it a bug?

in pydal/objects.py get_default_validator()

[nursix]

P.S. I think it's a bug - reference field should not require a value by default either.

[nursix]

web2py 3.0.14 with PyDAL 20251012.3

[nursix]

Still proposing this to fix the inconsistency:

diff --git a/pydal/objects.py b/pydal/objects.py
index da65aa69..540eec39 100644
--- a/pydal/objects.py
+++ b/pydal/objects.py
@@ -110,43 +110,45 @@ def get_default_validator(field, _cached_defaults={}):
     """returns the default validators a value of type"""
     from . import validators
 
+    validator = None
+
     # first we handle the special case when called in field.bind(table) and field.db is known
     ref = field.referenced_table()
     if ref is not None:
         validator = validators.IS_IN_DB(field.db, ref, ref._format)
         if field.type_name == "list:reference":
             validator = validators.IS_LIST_OF(validator)
-        return validators.DefaultValidatorProxy(validator)
 
     # then follow the normal workflow when field.db is unknown
     # we cache the validators for speed
-    if not _cached_defaults:
-        _cached_defaults = {
-            "integer": lambda: validators.IS_INT_IN_RANGE(),
-            "bigint": lambda: validators.IS_INT_IN_RANGE(),
-            "double": lambda: validators.IS_FLOAT_IN_RANGE(),
-            "decimal": lambda: validators.IS_FLOAT_IN_RANGE(),
-            "reference": lambda: validators.IS_INT_IN_RANGE(),
-            "big-reference": lambda: validators.IS_INT_IN_RANGE(),
-            "time": lambda: validators.IS_TIME(),
-            "date": lambda: validators.IS_DATE(),
-            "datetime": lambda: validators.IS_DATETIME(),
-            "list:string": lambda: validators.IS_LIST_OF_STRINGS(),
-            "list:integer": lambda: validators.IS_LIST_OF_INTS(),
-            "list:reference": lambda: validators.IS_LIST_OF_INTS(),
-            "password": lambda: validators.CRYPT(),
-            "json": lambda: validators.IS_JSON(),
-        }
-    validator_builder = _cached_defaults.get(field.type_name)
-    if validator_builder:
-        validator = validator_builder()
-    else:
-        validator = validators.Validator()
+    if validator is None:
+        if not _cached_defaults:
+            _cached_defaults = {
+                "integer": lambda: validators.IS_INT_IN_RANGE(),
+                "bigint": lambda: validators.IS_INT_IN_RANGE(),
+                "double": lambda: validators.IS_FLOAT_IN_RANGE(),
+                "decimal": lambda: validators.IS_FLOAT_IN_RANGE(),
+                "reference": lambda: validators.IS_INT_IN_RANGE(),
+                "big-reference": lambda: validators.IS_INT_IN_RANGE(),
+                "time": lambda: validators.IS_TIME(),
+                "date": lambda: validators.IS_DATE(),
+                "datetime": lambda: validators.IS_DATETIME(),
+                "list:string": lambda: validators.IS_LIST_OF_STRINGS(),
+                "list:integer": lambda: validators.IS_LIST_OF_INTS(),
+                "list:reference": lambda: validators.IS_LIST_OF_INTS(),
+                "password": lambda: validators.CRYPT(),
+                "json": lambda: validators.IS_JSON(),
+            }
+        validator_builder = _cached_defaults.get(field.type_name)
+        if validator_builder:
+            validator = validator_builder()
+        else:
+            validator = validators.Validator()
+
     if validator is not None and not field.notnull:
         validator = validators.IS_NULL_OR(validator)
     return validators.DefaultValidatorProxy(validator)
 
-
 class Row(BasicStorage):
     """
     A dictionary that lets you do d['a'] as well as d.a