Disable hidden timestamp attribute by default

datajoint/declare.py

@@ -10,6 +10,7 @@
 from .errors import DataJointError, _support_filepath_types, FILEPATH_FEATURE_SWITCH
 from .attribute_adapter import get_adapter
 from .condition import translate_attribute
+from .settings import config
 
 UUID_DATA_TYPE = "binary(16)"
 MAX_TABLE_NAME_LENGTH = 64
@@ -311,17 +312,18 @@ def declare(full_table_name, definition, context):
         external_stores,
     ) = prepare_declare(definition, context)
 
-    metadata_attr_sql = [
-        "`_{full_table_name}_timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP"
-    ]
-    attribute_sql.extend(
-        attr.format(
-            full_table_name=sha1(
-                full_table_name.replace("`", "").encode("utf-8")
-            ).hexdigest()
+    if config.get("enable_hidden_attributes", False):
+        metadata_attr_sql = [
+            "`_{full_table_name}_timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP"
+        ]
+        attribute_sql.extend(
+            attr.format(
+                full_table_name=sha1(
+                    full_table_name.replace("`", "").encode("utf-8")
+                ).hexdigest()
+            )
+            for attr in metadata_attr_sql
         )
-        for attr in metadata_attr_sql
-    )
 
     if not primary_key:
         raise DataJointError("Table must have a primary key")

datajoint/settings.py

@@ -47,6 +47,7 @@
         "display.show_tuple_count": True,
         "database.use_tls": None,
         "enable_python_native_blobs": True,  # python-native/dj0 encoding support
+        "enable_hidden_attributes": False,
         "filepath_checksum_size_limit": None,  # file size limit for when to disable checksums
     }
 )

tests/test_declare.py

@@ -3,6 +3,25 @@
 import datajoint as dj
 import inspect
 from datajoint.declare import declare
+from datajoint.settings import config
+
+
+@pytest.fixture(scope="function")
+def enable_hidden_attributes():
+    orig_config_val = config.get("enable_hidden_attributes")
+    config["enable_hidden_attributes"] = True
+    yield
+    if orig_config_val is not None:
+        config["enable_hidden_attributes"] = orig_config_val
+
+
+@pytest.fixture(scope="function")
+def disable_hidden_attributes():
+    orig_config_val = config.get("enable_hidden_attributes")
+    config["enable_hidden_attributes"] = False
+    yield
+    if orig_config_val is not None:
+        config["enable_hidden_attributes"] = orig_config_val
 
 
 def test_schema_decorator(schema_any):
@@ -373,9 +392,44 @@ class Table_With_Underscores(dj.Manual):
         schema_any(Table_With_Underscores)
 
 
-def test_hidden_attributes(schema_any):
+def test_hidden_attributes_default_value():
+    config_val = config.get("enable_hidden_attributes")
     assert (
-        list(Experiment().heading._attributes.keys())[-1].split("_")[2] == "timestamp"
-    )
-    assert any(a.is_hidden for a in Experiment().heading._attributes.values())
-    assert not any(a.is_hidden for a in Experiment().heading.attributes.values())
+        config_val is not None and not config_val
+    ), "Default value for enable_hidden_attributes is not False"
+
+
+def test_hidden_attributes_enabled(enable_hidden_attributes, schema_any):
+    orig_config_val = config.get("enable_hidden_attributes")
+    config["enable_hidden_attributes"] = True
+
+    msg = f"{Experiment().heading._attributes=}"
+    assert any(
+        a.name.endswith("_timestamp") for a in Experiment().heading._attributes.values()
+    ), msg
+    assert any(
+        a.name.startswith("_") for a in Experiment().heading._attributes.values()
+    ), msg
+    assert any(a.is_hidden for a in Experiment().heading._attributes.values()), msg
+    assert not any(a.is_hidden for a in Experiment().heading.attributes.values()), msg
+
+    if orig_config_val is not None:
+        config["enable_hidden_attributes"] = orig_config_val
+
+
+def test_hidden_attributes_disabled(disable_hidden_attributes, schema_any):
+    orig_config_val = config.get("enable_hidden_attributes")
+    config["enable_hidden_attributes"] = False
+
+    msg = f"{Experiment().heading._attributes=}"
+    assert not any(
+        a.name.endswith("_timestamp") for a in Experiment().heading._attributes.values()
+    ), msg
+    assert not any(
+        a.name.startswith("_") for a in Experiment().heading._attributes.values()
+    ), msg
+    assert not any(a.is_hidden for a in Experiment().heading._attributes.values()), msg
+    assert not any(a.is_hidden for a in Experiment().heading.attributes.values()), msg
+
+    if orig_config_val is not None:
+        config["enable_hidden_attributes"] = orig_config_val