On Tuesday, September 18, 2012 8:41:15 PM UTC-7, Michael Bayer wrote:
>
>
> On Sep 18, 2012, at 8:04 PM, Gerald Thibault wrote:
>
>
> before_insert() is not generally necessary, people frequently want to take
> advantage of the fact that it provides a built-in iteration of objects to
> be inserted, but this iteration can be done for the purposes of affecting
> the flush plan ahead of time within the before_flush() event, by iterating
> session.new. An object detected at this stage can be omitted from the
> insert by calling session.expunge(obj).
>
This did the trick. This is the current working event listener:
@event.listens_for(orm.sessionmaker(), 'before_flush')
def normalize_phonenumbers(session, flush_context, instances):
for obj in session.new:
if isinstance(obj, Phone):
if obj.location:
# we already have the location in the session
country = obj.location.country
else:
country = session.query(Location) \
.get(obj.location_id) \
.country
try:
number = phonenumbers.parse(obj.number, country)
obj.number = phonenumbers.format_number(number,
phonenumbers.PhoneNumberFormat.E164)
except:
session.expunge(obj)
I have one more question. When I do the following:
test = BusinessPhone(type='fax', number='2068857529', location_id=1)
session.add(test)
session.commit()
At what point is the 'location' relationship populated? I tried this and it
failed on this line, due to the relation not being populated:
country = obj.location.country
which necessitated adding the conditional manual load of Location. Am I
handling this in an appropriate way?
On Tuesday, September 18, 2012 4:29:43 PM UTC-7, Michael Bayer wrote:
>
>> On Sep 18, 2012, at 6:28 PM, Gerald Thibault wrote:
>>
>> > I am working with 2 models, a "Location" model, and a "Phone" model.
>> There is a one-to-many relationship between them.
>> >
>> > When a phone number is submitted, I need to format it using the
>> phonenumbers modules, which requires a country code, which exists on the
>> Location object. So the formatting can only happen after the flush(), as I
>> need to have the location_id populated, so I can grab the country code from
>> the parent Location. If the formatting of the phone number fails, I want
>> the entire object eliminated and not written to the db.
>>
>> At some point, the Phone is being associated with a Location object in
>> memory, and this would be independent of whether or not location_id is
>> present. The location_id can only be set, assuming this is
>> relationship() mechanics, if this is the case. So you shouldn't need a
>> flush() for this to happen, and you can perform this validation before a
>> flush plan is established.
>>
>> Otherwise if location_id is populated by some other means, that would
>> point to an area where you'd want to get Location objects present in memory
>> ahead of time, rather than relying upon primary keys alone.
>>
>> This might not be enough to solve your issue so feel free to add some
>> detail how location_id is coming into being here, such that the Location
>> isn't nearby.
>>
>>
>>
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