Is it possible to control somehow the order in which hooks are executed?

My use case is something like this:

class Festival(LifecycleModelMixin, models.Model):
    name = models.CharField(max_length=200)
    slug = models.SlugField(unique=True, null=True, blank=True)

    @hook(BEFORE_CREATE)
    def set_slug(self):
        self.slug = generate_slug(self.name)

    @hook(BEFORE_CREATE)
    def do_something_with_slug(self):
        print(f"Here we want to use our slug, but it could be None: {self.slug}")

i have been using django-lifecycle for a while to merely store the status. But I am realizing that I am building towards something like a Finite State machine.

So not sure if this library and https://github.com/viewflow/django-fsm overlap or I can use them in conjunction

I do find the idea of eschewing Signals for Hooks in this library for greater readability to be appealing.

Motivation

1. _get_model_property_names

Utility function _get_model_property_names is currently used for getting attribute names of properties to avoid potential side-effects during getting them. This workaround is great, but it isn't covering all possible properties types (e.g. functools.cached_property), only builtin property and cached_property from Django.

2. _potentially_hooked_methods cached on instance

Since _potentially_hooked_methods use cached_property, the results are cached on an instance, not on class -- but in my opinion, it's useless to have them valid for instance. Except for edge cases (dynamic definition of a method with hook during runtime) are the hooked methods the same for all instances of one model class. Because of that, _potentially_hooked_methods is evaluated 1000 times in this code:

[ModelInheritedFromLifecycleMixin() for _ in range(1000)]

That's measurable and unnecessary performance effect on model runtime (especially in combination with first point).

3. depth of searching in _potentially_hooked_methods

This method is currently using dir(self) to inspect all possible attributes with a hook -- that means scanning all delivered attributes from base DjangoModels and this is really unnecessary since @hook could be only on user's code, not on code from Django.

Solution

This PR contains refactoring of @hook decorator and part of LifecycleMixin code to use class-based cache to avoid problems mentioned above (evaluation of _potentially_hooked_methods for each new instance of model and evaluation of not known property types). Methods for scanning for possible hooks are now taken only from children's classes, not from Django Models.

PR is without BC break IMHO, if you don't use internals (accessing ._hooked manually, relying on the order of hooks evaluation or using @hook higher in the class tree than LifecycleMixin).

Questions

1. order of hook evaluation hooked methods in tests https://github.com/rsinger86/django-lifecycle/blob/a77e05c3376707b06dc765911968ad5fa37b168c/tests/testapp/models.py#L72-L93 and surrounding test method https://github.com/rsinger86/django-lifecycle/blob/a77e05c3376707b06dc765911968ad5fa37b168c/tests/testapp/tests/test_user_account.py#L88-L102

The test is currently expecting a specific order of hooks evaluation since both hooks are on the same attribute. Is it a wanted feature? I don't think so, hooked methods should not affect each other, and hooks shall have undeterminable order of evaluation. This PR also changes the way of working with excluded attributes internally, now is used sets and not lists (and that's the problem for the hooks order evaluation).

2. _get_model_descriptor_names There is no test for this method, respectively in all test cases this method returns empty iterable. What's the use case for this functionality?

Hi,

I've just tried implementing django-lifecycle into my project, but I'm having a hard time getting started.

My model looks like this:

class MyModel(LifecycleModel):
    ...
    model = models.CharField(max_length=200)
    ...

    @hook('before_update', when='model', has_changed=True)
    def on_content_change(self):
        self.model = 'test'

for some reason, the hook doesn't seem to be triggered. I've also tried stacking decorators to include other moments with the same result.

Conversely, this works:

class MyModel(LifecycleModel):
    ...
    model = models.CharField(max_length=200)
    ...

    def save(self, *args, **kwargs):
        self.model = 'test'
        super(MyModel, self).save(*args, **kwargs)

Am I missing something in my implementation? I'm on Django 2.2.8, python 3.7, and django-lifecycle 0.7.1.

...as discussed in #95

What do you think of this approach?

I have chosen that priority=0 is maximum priority, also I have added some priorities to constant values so end users doesn't have to think about the implementation (DEFAULT_PRIORITY, HIGHEST_PRIORITY, etc...)

Feel free to comment, suggest or edit whatever

First of all, thanks for this library. The API is really well done.

However, today I discovered that in #85 the change was made to force hooks to run inside of a transaction, which for many cases is desirable behavior, however one of my uses for lifecycle hooks is to queue background jobs in AFTER_SAVE assuming any calls to the model's save() will either observe the default django orm autocommit behavior or abide by whatever the behavior set by its current context will be.

Forcing a transaction / savepoint that wraps all model hooks using the atomic decorator means you can't safely make a call to an external service(or queue a celery / rq job) and assume the model changes will be visible. For example, it is not unusual for a background job to begin execution before the transaction that queued the job commits.

I'd be happy to open a PR that either reverts #85 or makes the current behavior configureable in some way depending no your preference if you are open to it.

Some of the work that the lifecycle mixin is during the initialization of new model objects is very expensive and unnecessary. It's calculating (and caching) field names and foreign key models per-object, rather than per-class / model. All instances of a model are going to have the same field names and foreign key model types so this work actually only needs to be done once per model type.

Replacing cached methods with cached classmethods yields a very sizable performance improvement when creating a bunch of new model instances.

I tried to query a model using LifecycleModel class and when doing an only('id') I got a RecursionError

    res = instance.__dict__[self.name] = self.func(instance)
  File "/app/.heroku/python/lib/python3.7/site-packages/django_lifecycle/mixins.py", line 169, in _watched_fk_model_fields
    for method in self._potentially_hooked_methods:
  File "/app/.heroku/python/lib/python3.7/site-packages/django/utils/functional.py", line 80, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "/app/.heroku/python/lib/python3.7/site-packages/django_lifecycle/mixins.py", line 152, in _potentially_hooked_methods
    attr = getattr(self, name)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/query_utils.py", line 135, in __get__
    instance.refresh_from_db(fields=[self.field_name])
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/base.py", line 628, in refresh_from_db
    db_instance = db_instance_qs.get()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/query.py", line 402, in get
    num = len(clone)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/query.py", line 256, in __len__
    self._fetch_all()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/query.py", line 1242, in _fetch_all
    self._result_cache = list(self._iterable_class(self))
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/query.py", line 55, in __iter__
    results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 1127, in execute_sql
    sql, params = self.as_sql()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 474, in as_sql
    extra_select, order_by, group_by = self.pre_sql_setup()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 54, in pre_sql_setup
    self.setup_query()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 45, in setup_query
    self.select, self.klass_info, self.annotation_col_map = self.get_select()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 219, in get_select
    cols = self.get_default_columns()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 641, in get_default_columns
    only_load = self.deferred_to_columns()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 1051, in deferred_to_columns
    self.query.deferred_to_data(columns, self.query.get_loaded_field_names_cb)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/query.py", line 680, in deferred_to_data
    add_to_dict(seen, model, field)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/sql/query.py", line 2167, in add_to_dict
    data[key] = {value}
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/models/fields/__init__.py", line 508, in __hash__
    return hash(self.creation_counter)
RecursionError: maximum recursion depth exceeded while calling a Python object

Using the below example in version 0.6.0, I am expecting to print a message any time someone changes a user's first name that is saved in SomeModel. From what I can tell from the documentation, I am setting everything up correctly. Am I misunderstanding how this works?

Assuming a model set up like this:

from django.conf import settings
from django.db import models
from django_lifecycle import LifecycleModel, hook

class SomeModel(LifecycleModel):
    user = models.ForeignKey(
        on_delete=models.CASCADE,
        to=settings.AUTH_USER_MODEL
    )
    # More fields here...

    @hook('after_update', when='user.first_name', has_changed=True)
    def user_first_name_changed(self):
        print(
            f"User's first_name has changed from "
            f"{self.initial_value('user.first_name')} to {user.first_name}!"
        )

When we then perform the following code, nothing prints:

from django.contrib.auth import get_user_model

# Create a test user (Jane Doe)
get_user_model().objects.create_user(
    username='test', 
    password=None, 
    first_name='Jane', 
    last_name='Doe'
)

# Create an instance
SomeModel.objects.create(user=user)

# Retrieve a new instance of the user
user = get_user_model().objects.get(username='test')

# Change the name (John Doe)
user.first_name = 'John'
user.save()

# Nothing prints from the hook

In the tests, I see that it is calling user_account._clear_watched_fk_model_cache() explicitly after changing the Organization.name. However, from looking at the code, I do not see this call anywhere except for the overridden UserAccount.save() method. Thus, saving the Organization has no way to notify the UserAccount that a change has been made, and therefore, the hook cannot possibly be fired. The only reason that I can see that the test is passing is because of the explicit call to user_account._clear_watched_fk_model_cache().

    def test_has_changed_is_true_if_fk_related_model_field_has_changed(self):
        org = Organization.objects.create(name="Dunder Mifflin")
        UserAccount.objects.create(**self.stub_data, organization=org)
        user_account = UserAccount.objects.get()

        org.name = "Dwight's Paper Empire"
        org.save()
        user_account._clear_watched_fk_model_cache()
        self.assertTrue(user_account.has_changed("organization.name"))

The GenericForeignKey field does not provide a get_internal_type method so when checking if it's a ForeignKey or not an AttributeError is raised.

This adjusts the code to ignore this AttributeError which effectively un-monitors the GenericForeignKey itself. However, it does leave the underlying ForeignKey to the ContentType table and the primary key storage field indexing into that table monitored. This does not enable support for hooking on the name of the GenericForeignKey, but hooking on the underlying fields that support that GenericForeignKey should still be possible.

closes #42

I ran into this earlier and it looks like maybe your README.md is not being included in 0.4.1:

Collecting django-lifecycle
  Using cached https://files.pythonhosted.org/packages/d4/ab/9daddd333fdf41bf24da744818a00ce8caa8e39d93da466b752b291ce412/django-lifecycle-0.4.1.tar.gz
    ERROR: Complete output from command python setup.py egg_info:
    ERROR: Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/pb/j_dpdd4n0858j1ym98g3884r0000gn/T/pip-install-x3_d5nyd/django-lifecycle/setup.py", line 30, in <module>
        long_description=readme(),
      File "/private/var/folders/pb/j_dpdd4n0858j1ym98g3884r0000gn/T/pip-install-x3_d5nyd/django-lifecycle/setup.py", line 7, in readme
        with open("README.md", "r") as infile:
      File "/Users/jefftriplett/.pyenv/versions/3.6.5/lib/python3.6/codecs.py", line 897, in open
        file = builtins.open(filename, mode, buffering)
    FileNotFoundError: [Errno 2] No such file or directory: 'README.md'
    ----------------------------------------
ERROR: Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/pb/j_dpdd4n0858j1ym98g3884r0000gn/T/pip-install-x3_d5nyd/django-lifecycle/

Hi, I'm writing this issue because I think the AFTER_DELETE hook does not work as expected on m2m relationships. If we have something like that:

class Product(LifecycleModel):
	title = models.Charfield(max_length=100)
	images = models.ManyToManyField(
        to="ProductImage", through="ProductImageRelationship", related_name="products"
    )

class ProductImageRelationship(LifecycleModel):
    product = models.ForeignKey("Product", on_delete=models.CASCADE)
    image = models.ForeignKey("ProductImage", on_delete=models.CASCADE)
    order = models.IntegerField(default=0, help_text="Lower number, higher priority")

class ProductImage(LifecycleModel):
	field_name = models.CharField(max_length=40)

If I write a hook on ProductImageRelationship model like this:

    @hook(AFTER_DELETE, on_commit=True)
    def deleting_image(self):
        print("Image deleted...")

the hook is never triggered when I do

p = Product.objects.get(pk=123)
i = p.images.first()
# to remove image from product do
p.images.remove(i)
# or do this
i.products.remove(p)

However, If I add a receiver like this:

@receiver(post_delete, sender=ProductImageRelationship)
def deleting_image(sender, instance, **kwargs):
    print("Image deleted...")

The receiver is triggered as is expected.

I think I'm doing it correctly :confused: but I'm not sure completely.

After saving an instance, reset the _initial_state using a on_commit callback. This makes the has_changed and initial_value API work with hooks that run with on_commit=True.

Fixes #117

When you use the dot notation in @hook decorator for the related fields (ForeignKey or OneToOneField) it hits the database for every object separately. It doesn't matter if you use select_related or not. Here are the models to test:

from django.contrib.auth.models import User
from django.db import models

from django_lifecycle import LifecycleModel, hook, AFTER_SAVE


class Organization(models.Model):
    name = models.CharField(max_length=250)


class Profile(LifecycleModel):
    user = models.OneToOneField(User, on_delete=models.CASCADE, null=True)
    employer = models.ForeignKey(Organization, on_delete=models.SET_NULL, null=True)
    bio = models.TextField(null=True, blank=True)
    age = models.PositiveIntegerField(null=True, blank=True)

    @hook(AFTER_SAVE, when='user.first_name', has_changed=True)
    @hook(AFTER_SAVE, when='user.last_name', has_changed=True)
    def user_changed(self):
        print('User was changed')

    @hook(AFTER_SAVE, when='employer.name', has_changed=True)
    def employer_changed(self):
        print('Employer was changed')

What I got when tried to fetch profiles (with db queries logging):

>>> from main.models import Profile
>>> queryset = Profile.objects.all()[:10]
>>> queryset
(0.000) SELECT "main_profile"."id", "main_profile"."user_id", "main_profile"."employer_id", "main_profile"."bio", "main_profile"."age" FROM "main_profile" LIMIT 10; args=(); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 2 LIMIT 21; args=(2,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 3 LIMIT 21; args=(3,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 4 LIMIT 21; args=(4,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 5 LIMIT 21; args=(5,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 6 LIMIT 21; args=(6,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 7 LIMIT 21; args=(7,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 8 LIMIT 21; args=(8,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 9 LIMIT 21; args=(9,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 10 LIMIT 21; args=(10,); alias=default
<QuerySet [<Profile: Profile object (1)>, <Profile: Profile object (2)>, <Profile: Profile object (3)>, <Profile: Profile object (4)>, <Profile: Profile object (5)>, <Profile: Profile object (6)>, <Profile: Profile object (7)>, <Profile: Profile object (8)>, <Profile: Profile object (9)>, <Profile: Profile object (10)>]>

>>> queryset = Profile.objects.select_related('user')[:10]
>>> queryset
(0.001) SELECT "main_profile"."id", "main_profile"."user_id", "main_profile"."employer_id", "main_profile"."bio", "main_profile"."age", "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "main_profile" LEFT OUTER JOIN "auth_user" ON ("main_profile"."user_id" = "auth_user"."id") LIMIT 10; args=(); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 2 LIMIT 21; args=(2,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 3 LIMIT 21; args=(3,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 4 LIMIT 21; args=(4,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 5 LIMIT 21; args=(5,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 6 LIMIT 21; args=(6,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 7 LIMIT 21; args=(7,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 8 LIMIT 21; args=(8,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 9 LIMIT 21; args=(9,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 10 LIMIT 21; args=(10,); alias=default
<QuerySet [<Profile: Profile object (1)>, <Profile: Profile object (2)>, <Profile: Profile object (3)>, <Profile: Profile object (4)>, <Profile: Profile object (5)>, <Profile: Profile object (6)>, <Profile: Profile object (7)>, <Profile: Profile object (8)>, <Profile: Profile object (9)>, <Profile: Profile object (10)>]>

>>> queryset = Profile.objects.select_related('user', 'employer')[:10]
>>> queryset
(0.001) SELECT "main_profile"."id", "main_profile"."user_id", "main_profile"."employer_id", "main_profile"."bio", "main_profile"."age", "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined", "main_organization"."id", "main_organization"."name" FROM "main_profile" LEFT OUTER JOIN "auth_user" ON ("main_profile"."user_id" = "auth_user"."id") LEFT OUTER JOIN "main_organization" ON ("main_profile"."employer_id" = "main_organization"."id") LIMIT 10; args=(); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 2 LIMIT 21; args=(2,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 3 LIMIT 21; args=(3,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 4 LIMIT 21; args=(4,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 5 LIMIT 21; args=(5,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 6 LIMIT 21; args=(6,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 7 LIMIT 21; args=(7,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 8 LIMIT 21; args=(8,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 9 LIMIT 21; args=(9,); alias=default
(0.000) SELECT "main_organization"."id", "main_organization"."name" FROM "main_organization" WHERE "main_organization"."id" = 1 LIMIT 21; args=(1,); alias=default
(0.000) SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login", "auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name", "auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff", "auth_user"."is_active", "auth_user"."date_joined" FROM "auth_user" WHERE "auth_user"."id" = 10 LIMIT 21; args=(10,); alias=default
<QuerySet [<Profile: Profile object (1)>, <Profile: Profile object (2)>, <Profile: Profile object (3)>, <Profile: Profile object (4)>, <Profile: Profile object (5)>, <Profile: Profile object (6)>, <Profile: Profile object (7)>, <Profile: Profile object (8)>, <Profile: Profile object (9)>, <Profile: Profile object (10)>]>

What happened？

There are 1 security vulnerabilities found in Django 3.2.8

• CVE-2022-34265

What did I do？

Upgrade Django from 3.2.8 to 4.0.6 for vulnerability fix

What did you expect to happen？

Ideally, no insecure libs should be used.

The specification of the pull request

PR Specification from OSCS

First of all, thanks for this project. I used to rely a lot on the built-in django signals. However, I have a project that is growing fast and django-lifecycle is helping us to bring some order to all these before_* and after_* actions.

One of my use-cases requires 2 features that django-lifecycle offers:

• The ability to compare against the initial state, i.e. obj.has_changed('field_name').
• Running hooks on commit to trigger background tasks.

Both features work well by separate. However calling has_changed or initial_value from a on_commit hook compares against the already saved state.

Looking into the code I noticed that the reason is that the save method resets the _inital_state just before returning:

[django_lifecycle/mixins.py#L177]

@transaction.atomic
def save(self, *args, **kwargs):
    # run before_* hooks
    save(...)
    # run after_* hooks

    self._initial_state = self._snapshot_state()

To reproduce the issue you can use this case:

from django_lifecycle import LifecycleModel, AFTER_UPDATE, hook


class MyModel(LifecycleModel):
    foo = models.CharField(max_length=3)

    @hook(AFTER_UPDATE, on_commit=True)
    def my_hook(self):
        assert self.has_changed('foo')   # <-- fails

obj = MyModel.objects.create(foo='bar')
obj.foo = 'baz'
obj.save()

I think It is arguable if this behavior is expected or if it is a bug. If it is expected, probably we should add a note in the docs mentioning that has_changed and initial_state does not make sense with on_commit=True. If it is a bug, any idea how to address it? I can contribute with a PR if necessary and if we agree on a solution.