Source code for cobra_component_models.orm.mixin.timestamp_mixin
# Copyright (c) 2019, Novo Nordisk Foundation Center for Biosustainability,
# Technical University of Denmark.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
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"""Provide a mixin that tracks creation and update timestamps."""
from datetime import datetime, timezone
from sqlalchemy import Column, DateTime
[docs]def timezone_aware_now():
"""Return the date and time in this moment in the universal timezone."""
return datetime.now(timezone.utc)
[docs]class TimestampMixin:
"""
Define creation and update time columns to be mixed in with other tables.
Attributes
----------
created_on : datetime
By default this value is populated at instantiation with the time of
the moment.
updated_on : datetime
The time is automatically populated whenever the database model is
updated.
"""
created_on: datetime = Column(
DateTime(timezone=True), nullable=False, default=timezone_aware_now
)
updated_on: datetime = Column(
DateTime(timezone=True), nullable=True, onupdate=timezone_aware_now
)