On Sat, Jun 11, 2022 at 12:13:16AM +1000, Mike Dewhirst wrote: > On 10/06/2022 11:24 pm, Ryan Nowakowski wrote: > > On Fri, Jun 10, 2022 at 05:52:48PM +1000, Mike Dewhirst wrote: > > > I think the solution might be to hash note.title and note.note into a new > > > field note.hash on being auto-created. On subsequent saves, compare the > > > latest hash with note.hash to decide whether to delete auto-inserted notes > > > prior to generating the next set. Those subsequent saves could be months > > > or > > > years later. > > Hashing is useful if you want to check that something has been > > unexpectedly changed. I assume the note can only be changed through > > your web app so you know when a user is changing a note. > > These are automatically generated notes which taken together constitute > advice on how to deal with the analysis. Users can edit them. For example, > someone might record some action taken regarding the advice. I don't want to > delete that. If nothing has been edited, it is safe to delete. > > So how do I know it is the same as when originally generated - and safe to > delete - except by storing a hash of the interesting fields.
Because when the user edits a note, during the form.save()(assuming you're using Django forms), you'll set `altered_by_user` to True. > And if that is the best approach, what sort of hashing will survive Python > upgrades etc? Pick a hash algorithm[1](ex: sha256). The output will remain the same even with Python upgrades. [1] https://docs.python.org/3/library/hashlib.html > > Since you're > > expecting users to change some of the notes and you know when they do, > > hashing might be overkill. Instead, add a boolean `altered_by_user` > > field to the note model. Initially when you automatically create the > > note altered_by_user would be set to False. If a user changes the note, > > set altered_by_user to True. > > Not sure this would work. Note creation and eventually automatic deletion is > all driven from model methods executed on saving. Why wouldn't this work? During note creation, altered_by_user would be set to False automatically because that's the default. When automatically deleting, do: Note.objects.filter(altered_by_user=False).delete() -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/20220612210931.GA32625%40fattuba.com.
