用一个接收器合并多个 post_save 信号

Question

所以我阅读了 Django 源代码（1.5 后），您现在可以将多个信号注册到接收器函数：

def receiver(signal, **kwargs):
    """
    A decorator for connecting receivers to signals. Used by passing in the
    signal (or list of signals) and keyword arguments to connect::

        @receiver(post_save, sender=MyModel)
        def signal_receiver(sender, **kwargs):
            ...

        @receiver([post_save, post_delete], sender=MyModel)
        def signals_receiver(sender, **kwargs):
            ...

    """
    ... implementation code...

但是，我想将来自不同发件人的多个 post_save 信号注册到同一个函数。现在，我只是打电话

post_save.connect(fn_name, model_name)

对于我拥有的每个模型。有没有更好的方法来使用新的 Django 1.5 @receiver 装饰器功能？

Answer 1

您可以跳过model_name，您将连接到所有模型 post_save。然后你可以过滤你是否在处理程序中的正确模型：

post_save.connect(foo)

def foo(sender, **kwargs):
    if sender not in [FooModel, BarModel]:
        return
    ... actual code ...

或者您可以根据模型中的字段进行过滤：

def foo(sender, **kwargs):
    if not getattr(sender, 'process_by_foo', False):
        return
    ... actual code ...

Answer 2

根据Django documentation on receivers，默认情况下，接收者不需要连接到特定的发送者。所以你描述的是默认的 Django 功能。

换句话说，要使用@receiver 装饰器执行此操作，您只需不在装饰器中指定发送者。例如：

@receiver(post_save) # instead of @receiver(post_save, sender=Rebel)
def set_winner(sender, instance=None, created=False, **kwargs):
    list_of_models = ('Rebel', 'Stormtrooper', 'Battleground')
    if sender.__name__ in list_of_models: # this is the dynamic part you want
        if created: # only run when object is first created
            ... set the winner ...

这假设模型看起来像：

class Rebel(models.Model):
    ...

class Stormtrooper(models.Model):
    ...

class Battleground(models.Model):
    ...

Answer 3

您可以使用@receiver decorator：

from django.dispatch import receiver

@receiver(post_save, sender=Model1)
@receiver(post_save, sender=Model2)
@receiver(post_save, sender=Model3)
def my_signal_handle(sender , **kwargs)
    # some code here

Answer 4

def receiver_with_multiple_senders(signal, senders, **kwargs):
    """
    Based on django.dispatch.dispatcher.receiver

    Allows multiple senders so we can avoid using a stack of
    regular receiver decorators with one sender each.
    """

    def decorator(receiver_func):
        for sender in senders:
            if isinstance(signal, (list, tuple)):
                for s in signal:
                    s.connect(receiver_func, sender=sender, **kwargs)
            else:
                signal.connect(receiver_func, sender=sender, **kwargs)

        return receiver_func

    return decorator