django-status-signal

enhanced django signal which enable you to trigger a signal only if the model instance is in a certain status

Install

pip3 install django-status-signal

Usage

In many scenarios, you may want to trigger a function only when a model's status has been changed to a certain status. But the default django's signal can only use the sender(an model instance) to search the receivers. Here comes the solution.

from django_status_signal import Signal
class Task(models.Model):
    status = models.CharField(
        choices=(
            ("start", "start"),
            ("doing", "doing"),
            ("success", "success"),
            ("fail", "fail"),
        ),
        max_length=31,
    )
# create a signal and connect it to different status
mysignal = Singal()
mysignal.connect(send_message, Task, dispatch_status="fail")
mysignal.connect(reward, Task, dispatch_status="success")
# call the signal
task = Task.objects.create('start')
mysignal.send(Task, instance=task, task.status)  # nothing will happen
task.status = 'success'
task.save()
mysignal.send(Task, instance=task, task.status)  # the send_message will be called

TODO

when this project is stable enough, I want to merge the code into django project, so all the post_save, post_delete can accept dispatch_status parameter.

LICENSE

there are many code copied from the django project, so the LICENSE should stay the same as django's LICENSE.