How do you get the instance of the imported object after importing with django-import-export? - django-admin

Question

I'm trying to add objects to a related model after importing using django-import-export.
My Models
class Event(models.Model):
title = models.CharField(max_length=150)
class EventSession(models.Model):
event = models.ForeignKey(Event, on_delete=models.CASCADE, related_name="sessions")
start_date = models.DateTimeField()
end_date = models.DateTimeField()
My Import Data
id
start_date
start_time
minutes
sessions
9/1/21
10:00
60
2
9/8/21
10:00
60
3
My ModelResource Class
I am trying to override after_import_row to get the imported event and then create
the event sessions, but I don't know how to get the imported event.
class EventResource(resources.ModelResource):
start_date = fields.Field()
start_time = fields.Field()
def after_import_row(self, row, row_result, row_number=None, **kwargs):
""" After importing the row, get the saved event and save the event sessions."""
event = get_instance() # HOW TO GET THE INSTANCE????
start_datetime = timezone.make_aware(
datetime.combine(row["start_date"], row["start_time"])
)
end_datetime = start_datetime + timedelta(minutes=row["minutes"])
first_session = EventSession(
event=event,
start_date=start_datetime,
end_date=end_datetime,
)
first_session.save()
for _ in range(1, row["sessions"]):
# Sessions are always consecutive days
start_datetime = start_datetime + timedelta(days=1)
end_datetime = end_datetime + timedelta(days=1)
event_session = EventSession(
event=event,
start_date=start_datetime,
end_date=end_datetime,
)
event_session.save()
return super().after_import_row(
row, row_result, row_number=row_number, **kwargs
)
class Meta:
model = Event
fields = (
"id",
"title",
"start_date",
"start_time",
"sessions",
)
skip_unchanged = True
report_skipped = True

Answer 1

I figured out a solution. I can save the instance as an attribute of the EventResource object by overriding after_save_instance().
def after_save_instance(self, instance, using_transactions, dry_run):
self.instance = instance
return super().after_save_instance(instance, using_transactions, dry_run)
Then in after_import_row(), I use:
event = self.instance

Answer 2

You can also get hold of the instance id as follows:
def after_import_row(self, row, row_result, row_number=None, **kwargs):
print(row_result.object_id)
Obviously you can then load the object if required.
An alternative is to override after_import(). In this case, the result object passed to the method contains rows, which is a list of all imported rows.
def after_import(self, dataset, result, using_transactions, dry_run, **kwargs):
for row_result in result:
print(row_result.object_id)