Fixed signals can not connect to OneToOneField (#572)

[954-Ivory]

Incidentally, the file storage of the signal has been changed.

[lgtm-com]

This pull request introduces 1 alert when merging b99abe3 into d4b97af - view on LGTM.com

new alerts:

• 1 for Unused import

[auvipy]

OneToOneRel is a private API as far as I know, can you provide a testt case of examples of what you were actually trying to acheive?

[954-Ivory]

Test case:

# admin.py
class MyPeriodicTaskInline(admin.StackedInline):
    model = MyPeriodicTask
    # ...
    # I want to render a `StackedInline` of `MyPeriodicTask` in `OtherModelAdmin` with my scene..
    # But it's not important.

class OtherModelAdmin(admin.ModelAdmin):
    model = OtherModel
    inlines = (
        MyPeriodicTaskInline,
    )

# models.py
class MyPeriodicTask(PeriodicTask):
    other_model = models.ForeignKey(
        'OtherModel',
        null=True,
        on_delete=models.CASCADE
    )

    def save(self, *args, **kwargs):
        self.kwargs = json.dumps('a_field_key',self.other_model.a_field)
        super().save(*args, **kwargs)
        # The bug is in it: 
        # This `save()` will call the `save_base()`.
        # But in `save_base()`, it will set `pre_save.sender = MyPeriodicTask`, not `PeriodicTask`.
        # So, the `PeriodicTask` can not receive signal with
        # [signals.pre_delete.connect(PeriodicTasks.changed, sender=PeriodicTask)](https://github.com/celery/django-celery-beat/blob/d4b97af62889527582194f3932e013ad972a88b3/django_celery_beat/models.py#L625)
        # [signals.pre_save.connect(PeriodicTasks.changed, sender=PeriodicTask)](https://github.com/celery/django-celery-beat/blob/d4b97af62889527582194f3932e013ad972a88b3/django_celery_beat/models.py#L625)

# query
my_periodic_task = MyPeriodicTask.first()
my_periodic_task.enabled = not my_periodic_task.enabled
my_periodic_task.save()
# the `PeriodicTasks.changed` will not be call.

Even without not overwrite save(), the pre_save.sender still be MyPeriodicTask.__class__.
Because in MyPeriodicTask, the self is MyPeriodicTask.
And Django use self.class to set sender.
delete() is the same, look this.

[954-Ivory]

We have two way to fix it.

1. Don't use signal, call PeriodicTasks.changed() in PeriodicTask.save() and PeriodicTask.delete().
2. Like this PR, use reverse related to get all OneToOneField, then get thier __class__, connect to the signal.

Because OneToOneRel is a definite type for judge reverse related which is OnetoOneField, so I use it.

[auvipy]

i would prefer first approach

[auvipy]

can you also add the tests as well

[954-Ivory]

can you also add the tests as well

Yep, but I got the problem like this:
https://stackoverflow.com/questions/502916/django-how-to-create-a-model-dynamically-just-for-testing
I'm trying to solve it.

[auvipy]

is that related to this patch?

[954-Ivory]

is that related to this patch?

Yep, I solved it.
Because I need to create the model in testing.

[auvipy]

looking for now-outdated files... none found
pickling environment... done
checking consistency... done

==============================
Undocumented Autodoc Modules

py

• django_celery_beat.signals

[954-Ivory]

looking for now-outdated files... none found pickling environment... done checking consistency... done

==============================

Undocumented Autodoc Modules

py

• django_celery_beat.signals

I consolidated some files about Signals before (follow Django best practices).
Does it conflict about CI/CD?

[auvipy]

the doc gen expects some documentation about the newly created module

[954-Ivory]

the doc gen expects some documentation about the newly created module

Right, I will add the docs.

[auvipy]

some minor Error: ERROR: flake8: commands failed
Error: ERROR: pydocstyle: commands failed need to be fixed

[954-Ivory]

some minor Error: ERROR: flake8: commands failed Error: ERROR: pydocstyle: commands failed need to be fixed

It seems like some code specification problem.
I have tried to format them.
The migrations files is be generated, I didn't format it.
How to ignore code check of the migrations files?

[auvipy]

lets try this and report if anything goes wrong

[auvipy]

can you help reviewing #563?