secnot / django-isbn-field Goto Github PK

Hey @secnot,

First of all, thanks for creating and opensourcing ISBNField!

I've run into an issue with using unique=True. Apparently ISBNField breaks Django's pre-save uniquess check by doing the checks using the dirty ISBN instead of the cleaned one.

I've created a failing test case here: salomvary@306ab05

Instead of the validation error, it fails with django.db.utils.IntegrityError: UNIQUE constraint failed: tests_uniquecleanisbnmodel.isbn which is not what is expected for these cases.

The problem lies in Django getting the dirty value instead of the clean one here: https://github.com/django/django/blob/ca9872905559026af82000e46cde6f7dedc897b6/django/db/models/base.py#L1097

I am trying to come up with a workaround but as someone who has built zero custom fields so far, I might be slower than you spotting the problem. If you have any insights, let me know!

Greetings @secnot and thank you for this repo.

I have encounter an issue where the field validation fails. EANs are the barcode versions of ISBNs, and there are scenarios where these numbers can pass an ISBN check sum, but still not be valid. 6610000352289, is one such example.

stdnum contains validation for EANs as well. Could you please add this validation check to prevent this from happening? I haven't come up with a good set of conditions to be absolutely sure it's an EAN and not an ISBN and vice versa (for instance, EANs can also start with 978 so that doesn't work), but perhaps the the algorithm is different between the two and that may suffice.

Thank you again!

https://www.abebooks.co.uk/9788320708011/dzieci-z-dworca-ZOO-Christiane-832070801X/plp

This books ISBN is rejected by ISBN Field