A list of all the signals that Django sends. All built-in signals are sent
using the send() method.
lihat juga
See the documentation on the signal dispatcher for information regarding how to register for and receive signals.
The authentication framework sends signals when a user is logged in / out.
The django.db.models.signals module defines a set of signals sent by the
model system.
Peringatan
Many of these signals are sent by various model methods like
__init__() or save() that you can
override in your own code.
If you override these methods on your model, you must call the parent class' methods for this signals to be sent.
Note also that Django stores signal handlers as weak references by default,
so if your handler is a local function, it may be garbage collected. To
prevent this, pass weak=False when you call the signal's connect().
Catatan
Model signals sender model can be lazily referenced when connecting a
receiver by specifying its full application label. For example, an
Answer model defined in the polls application could be referenced
as 'polls.Answer'. This sort of reference can be quite handy when
dealing with circular import dependencies and swappable models.
pre_init¶django.db.models.signals.pre_init¶Whenever you instantiate a Django model, this signal is sent at the beginning
of the model's __init__() method.
Argumen dikirim dengan dinyal ini:
senderargs__init__():kwargs__init__():For example, the tutorial has this line:
p = Poll(question="What's up?", pub_date=datetime.now())
The arguments sent to a pre_init handler would be:
| Argument | Nilai |
|---|---|
sender |
Poll (the class itself) |
args |
[] (an empty list because there were no positional
arguments passed to __init__().) |
kwargs |
{'question': "What's up?", 'pub_date': datetime.now()} |
post_init¶django.db.models.signals.post_init¶Like pre_init, but this one is sent when the __init__() method finishes.
Argumen dikirim dengan dinyal ini:
senderinstancepre_save¶django.db.models.signals.pre_save¶This is sent at the beginning of a model's save()
method.
Argumen dikirim dengan dinyal ini:
senderinstancerawTrue if the model is saved exactly as presented
(i.e. when loading a fixture). One should not query/modify other
records in the database as the database might not be in a
consistent state yet.menggunakanupdate_fieldsModel.save(), or None
if update_fields wasn't passed to save().post_save¶django.db.models.signals.post_save¶Like pre_save, but sent at the end of the
save() method.
Argumen dikirim dengan dinyal ini:
senderinstancecreatedTrue if a new record was created.rawTrue if the model is saved exactly as presented
(i.e. when loading a fixture). One should not query/modify other
records in the database as the database might not be in a
consistent state yet.menggunakanupdate_fieldsModel.save(), or None
if update_fields wasn't passed to save().pre_delete¶django.db.models.signals.pre_delete¶Sent at the beginning of a model's delete()
method and a queryset's delete() method.
Argumen dikirim dengan dinyal ini:
senderinstancemenggunakanpost_delete¶django.db.models.signals.post_delete¶Like pre_delete, but sent at the end of a model's
delete() method and a queryset's
delete() method.
Argumen dikirim dengan dinyal ini:
senderinstanceThe actual instance being deleted.
Note that the object will no longer be in the database, so be very careful what you do with this instance.
menggunakanm2m_changed¶django.db.models.signals.m2m_changed¶Sent when a ManyToManyField is changed on a model
instance. Strictly speaking, this is not a model signal since it is sent by the
ManyToManyField, but since it complements the
pre_save/post_save and pre_delete/post_delete
when it comes to tracking changes to models, it is included here.
Argumen dikirim dengan dinyal ini:
senderManyToManyField. This class is automatically
created when a many-to-many field is defined; you can access it using the
through attribute on the many-to-many field.instancesender, or of the class the
ManyToManyField is related to.actionA string indicating the type of update that is done on the relation. This can be one of the following:
"pre_add""post_add""pre_remove""post_remove""pre_clear""post_clear"reversemodelpk_setFor the pre_add, post_add, pre_remove and post_remove
actions, this is a set of primary key values that have been added to
or removed from the relation.
For the pre_clear and post_clear actions, this is None.
menggunakanSebagai contoh, jika sebuah Pizza dapat memiliki banyak obyek Topping, dimodelkan seperti ini:
class Topping(models.Model):
# ...
pass
class Pizza(models.Model):
# ...
toppings = models.ManyToManyField(Topping)
If we connected a handler like this:
from django.db.models.signals import m2m_changed
def toppings_changed(sender, **kwargs):
# Do something
pass
m2m_changed.connect(toppings_changed, sender=Pizza.toppings.through)
and then did something like this:
>>> p = Pizza.objects.create(...)
>>> t = Topping.objects.create(...)
>>> p.toppings.add(t)
argumen-argumen dikirim ke penangan m2m_changed (toppings_changed dalam contoh diatas) akan menjadi:
| Argument | Nilai |
|---|---|
sender |
Pizza.toppings.through (kelas m2m menengah) |
instance |
p (the Pizza instance being modified) |
action |
"pre_add" (followed by a separate signal with "post_add") |
reverse |
False (Pizza contains the
ManyToManyField, so this call
modifies the forward relation) |
model |
Topping (kelas dari obyek ditambahkan pada Pizza) |
pk_set |
{t.id} (sejak hanya Topping t yang ditambahkan ke hubungan) |
menggunakan |
"default" (since the default router sends writes here) |
And if we would then do something like this:
>>> t.pizza_set.remove(p)
the arguments sent to a m2m_changed handler would be:
| Argument | Nilai |
|---|---|
sender |
Pizza.toppings.through (kelas m2m menengah) |
instance |
t (instance Topping sedang dirubah) |
action |
"pre_remove" (followed by a separate signal with "post_remove") |
reverse |
True (Pizza contains the
ManyToManyField, so this call
modifies the reverse relation) |
model |
Pizza (kelas dari obyek dipindahkan dari Topping) |
pk_set |
{p.id} (since only Pizza p was removed from the
relation) |
menggunakan |
"default" (since the default router sends writes here) |
class_prepared¶django.db.models.signals.class_prepared¶Sent whenever a model class has been "prepared" -- that is, once model has been defined and registered with Django's model system. Django uses this signal internally; it's not generally used in third-party applications.
Sejak sinyal ini dikirim selama pengolahan pengumpulan registrar aplikasi, dan AppConfig.ready() berjalan setelah registrar sepenuhnya dikumpulkan, penerima tidak dapat dihubungkan di metode itu. Satu kemungkinan adalah menghubungkan mereka AppConfig.__init__() sebagai gantinya, merawat tidak untuk mengimpor model atau panggilan pemicu pada registrar aplikasi.
Arguments that are sent with this signal:
senderSignals sent by django-admin.
pre_migrate¶django.db.models.signals.pre_migrate¶Sent by the migrate command before it starts to install an
application. It's not emitted for applications that lack a models module.
Argumen dikirim dengan dinyal ini:
senderAppConfig instance for the application about to
be migrated/synced.app_configsender.verbosityIndicates how much information manage.py is printing on screen. See
the --verbosity flag for details.
Functions which listen for pre_migrate should adjust what they
output to the screen based on the value of this argument.
interactiveIf interactive is True, it's safe to prompt the user to input
things on the command line. If interactive is False, functions
which listen for this signal should not try to prompt for anything.
For example, the django.contrib.auth app only prompts to create a
superuser when interactive is True.
menggunakanplanTrue) or applied (False).appsApps mengandung keadaan dari proyek sebelum perpindahan berjalan. Itu harus digunakan sebagai gantinya dari registrar apps global untuk mengambil model yang anda ingin lakukan tindakan.post_migrate¶django.db.models.signals.post_migrate¶Sent at the end of the migrate (even if no migrations are run) and
flush commands. It's not emitted for applications that lack a
models module.
Handlers of this signal must not perform database schema alterations as doing
so may cause the flush command to fail if it runs during the
migrate command.
Argumen dikirim dengan dinyal ini:
senderAppConfig instance for the application that was
just installed.app_configsender.verbosityIndicates how much information manage.py is printing on screen. See
the --verbosity flag for details.
Functions which listen for post_migrate should adjust what they
output to the screen based on the value of this argument.
interactiveIf interactive is True, it's safe to prompt the user to input
things on the command line. If interactive is False, functions
which listen for this signal should not try to prompt for anything.
For example, the django.contrib.auth app only prompts to create a
superuser when interactive is True.
menggunakandefault
database.planTrue) or applied (False).appsApps mengandung keadaan dari proyek setelah perpindahan berjalan. Itu harus digunakan sebagai gantinya dari registrar apps global untuk mengambil model yang anda ingin lakukan tindakan.For example, you could register a callback in an
AppConfig like this:
from django.apps import AppConfig
from django.db.models.signals import post_migrate
def my_callback(sender, **kwargs):
# Your specific logic here
pass
class MyAppConfig(AppConfig):
...
def ready(self):
post_migrate.connect(my_callback, sender=self)
Catatan
If you provide an AppConfig instance as the sender
argument, please ensure that the signal is registered in
ready(). AppConfigs are recreated for
tests that run with a modified set of INSTALLED_APPS (such as
when settings are overridden) and such signals should be connected for each
new AppConfig instance.
Signals sent by the core framework when processing a request.
request_started¶django.core.signals.request_started¶Sent when Django begins processing an HTTP request.
Argumen dikirim dengan dinyal ini:
senderdjango.core.handlers.wsgi.WsgiHandler -- that
handled the request.environenviron dictionary provided to the request.request_finished¶django.core.signals.request_finished¶Sent when Django finishes delivering an HTTP response to the client.
Argumen dikirim dengan dinyal ini:
sendergot_request_exception¶django.core.signals.got_request_exception¶This signal is sent whenever Django encounters an exception while processing an incoming HTTP request.
Argumen dikirim dengan dinyal ini:
senderrequestHttpRequestSignals only sent when running tests.
setting_changed¶django.test.signals.setting_changed¶This signal is sent when the value of a setting is changed through the
django.test.TestCase.settings() context manager or the
django.test.override_settings() decorator/context manager.
It's actually sent twice: when the new value is applied ("setup") and when the
original value is restored ("teardown"). Use the enter argument to
distinguish between the two.
You can also import this signal from django.core.signals to avoid importing
from django.test in non-test situations.
Argumen dikirim dengan dinyal ini:
sendersettingvaluevalue is None.enterTrue if the setting is applied, False if restored.Signals sent by the database wrapper when a database connection is initiated.
connection_created¶django.db.backends.signals.connection_created¶Sent when the database wrapper makes the initial connection to the database. This is particularly useful if you'd like to send any post connection commands to the SQL backend.
Argumen dikirim dengan dinyal ini:
senderdjango.db.backends.postgresql.DatabaseWrapper or
django.db.backends.mysql.DatabaseWrapper, etc.connectionAgt 01, 2018