Signals

.. py:currentmodule:: django_q

Available signals

Django Q emits the following signals during its lifecycle.

Before enqueuing a task """""""""""""""""""""""

The django_q.signals.pre_enqueue signal is emitted before a task is enqueued. The task dictionary is given as the task argument.

Before executing a task """""""""""""""""""""""

The django_q.signals.pre_execute signal is emitted before a task is executed by a worker. This signal provides two arguments:

• task: the task dictionary.
• func: the actual function that will be executed. If the task was created with a function path, this argument will be the callable function nonetheless.

After executing a task """""""""""""""""""""" The django_q.signals.post_execute signal is emitted after a task is executed by a worker and processed by the monitor. It included the task dictionary with the result.

Subscribing to a signal

Connecting to a Django Q signal is done the same as any other Django signal::

from django.dispatch import receiver
from django_q.signals import pre_enqueue, pre_execute, post_execute

@receiver(pre_enqueue)
def my_pre_enqueue_callback(sender, task, **kwargs):
    print(f"Task {task['name']} will be queued")

@receiver(pre_execute)
def my_pre_execute_callback(sender, func, task, **kwargs):
    print(f"Task {task['name']} will be executed by calling {func}")

@receiver(post_execute)
def my_post_execute_callback(sender, task, **kwargs):
    print(f"Task {task['name']} was executed with result {task['result']}")