id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30710	impossible without workarounds to see which fields changed when subscribing to signals from generic views	MaxR	nobody	"for example I have simple `generic view`:

{{{
#views.py
class CollectorUpdate(generic.UpdateView):
    model = ReportBase
    fields = ['title', 'db', 'additionalPath', 'start_date', 'end_date', 'reportTimestamp',
              'updMethod', 'cronStr', 'code', 'code_renew']
    template_name = 'collector/collector_update_form.html'
}}}

and subscribe to `post_save` signal:

{{{
@receiver(signal=signals.post_save, sender=ReportBase)
def runCron(sender, **kwargs):
    """"""Signal handler. Run cron after post_save signal on """"""
    collector = kwargs.get('instance')
    updated_fields = kwargs.get('update_fields')
}}}

but `updated_fields`  always is `None`

I think the problem is that in generic.UpdateView into `.save()` method it is necessary to register a field `field_update` with interesting for me fields.
As workaround i'm using an instyance of saved object:
{{{
 collector = kwargs.get('instance')
}}}
but it's looks strange and it is inconvenient. I have to do a lot of extra work"	Uncategorized	closed	Uncategorized	2.1	Normal	wontfix			Unreviewed	0	0	0	0	0	0