UserstampMiddleware

middleware.py

# -*- coding: utf-8 -*-
from django.db.models import signals
from django.utils.functional import curry
from rest_framework import authentication


class UserstampMiddleware(object):
    """Add user created_by and updated_by foreign key refs to any model automatically.
    Almost entirely taken from https://github.com/Atomidata/django-audit-log/blob/master/audit_log/middleware.py"""
    def process_request(self, request):
        if not request.method in ('GET', 'HEAD', 'OPTIONS', 'TRACE'):
            try:
                user = request.user

                if not user.is_authenticated():
                    # try basic auth
                    auth = authentication.BasicAuthentication().authenticate(request)

                    user, _ = auth if auth else (None, None)
            except (authentication.exceptions.AuthenticationFailed, KeyError):
                user = None

            func = curry(userstampable, user)

            signals.pre_save.connect(func, dispatch_uid = (self.__class__, request), weak = False)

    def process_response(self, request, response):
        signals.pre_save.disconnect(dispatch_uid = (self.__class__, request))

        return response

signals.py

# -*- coding: utf-8 -*-
from django.db.models.signals import post_save, pre_save
from django.dispatch import receiver
from django.utils import timezone


@receiver(pre_save)
def timestampable(sender, instance, *args, **kwargs):
    if hasattr(instance, 'created_at'):
        if instance._state.adding and not instance.created_at:
            instance.created_at = timezone.now().replace(microsecond=0)

    if hasattr(instance, 'updated_at'):
        if instance._state.adding or instance.is_dirty():
            instance.updated_at = timezone.now().replace(microsecond=0)


# bound by UserstampMiddleware
def userstampable(user, sender, instance, **kwargs):
    if hasattr(instance, 'created_by_id') and instance._state.adding:
        instance.created_by = instance.created_by or user

    if hasattr(instance, 'updated_by_id'):
        instance.updated_by = user