django - 信号不起作用

Question

我正在尝试从其状态创建用户的活动流。

楷模：

class Status(models.Model):
    body = models.TextField(max_length=200)
    image = models.ImageField(blank=True, null=True, upload_to=get_upload_file_name)
    privacy = models.CharField(max_length=1,choices=PRIVACY, default='F')
    pub_date = models.DateTimeField(auto_now_add=True, auto_now=False)
    user = models.ForeignKey(User)

class Activity(models.Model):
    actor = models.ForeignKey(User)
    action = models.CharField(max_length=100)
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = generic.GenericForeignKey('content_type', 'object_id')
    pub_date = models.DateTimeField(auto_now_add=True, auto_now=False)

但是，虽然我创建了一个新状态，但它不会从post_save信号创建新活动。

信号：

from django.contrib.contenttypes.models import ContentType
from django.db.models.signals import post_save
from status.models import Status
from models import Activity

def create_activity_item(sender, instance, signal, *args, **kwargs):
    if kwargs.get('created', True):
        ctype = ContentType.objects.get_for_model(instance)

        if ctype.name == 'Status':
            action = ' shared '

            activity = Activity.objects.get_or_create(
                actor = instance.user,
                action = action,
                content_type = ctype,
                object_id = instance.id,
                pub_date = instance.pubdate
            )

post_save.connect(create_activity_item, sender=Status)

我究竟做错了什么？请帮我解决这个问题。我将非常感激。谢谢。

更新：

但是，这样做会创建活动：

@receiver(post_save, sender=Status)
def create(sender, instance, **kwargs):
    if kwargs.get('created',True):
        ctype = ContentType.objects.get_for_model(instance)
        activity = Activity.objects.get_or_create(
            actor = instance.user,
            action = ' shared ',
            content_type = ctype,
            object_id = instance.id,
            pub_date = instance.pub_date
        )

为什么以上不适用呢？

Answer 1

好像你的post_save.connect没有被执行。你应该在某处导入signals。对于django 1.7，建议在app的config ready（）函数中执行此操作。阅读文档中的"Where should this code live?"侧注。

例如，如果您的应用程序名为activity：

活动/ __ init__.py

default_app_config = 'activity.apps.ActivityAppConfig'

活动/ apps.py

from django.apps import AppConfig

class ActivityAppConfig(AppConfig):
    name = 'activity'

    def ready(self):
        import activity.signals

并且不要忘记将dispatch_uid添加到您的connect()电话：

post_save.connect(create_activity_item, sender=Status,
                  dispatch_uid="create_activity_item")

更新：name的ContentType属性始终为小写。所以你应该将if语句更改为：

if ctype.name == 'status':

Answer 2

没有触及apps.py这对我有用。

class MyModel(models.Model):
    """ MyModel fields go """
    body = models.TextField(max_length=200)
    pub_date = models.DateTimeField(auto_now_add=True, auto_now=False)


def post_save_actions(sender, instance, created, **kwargs):
    if created:
        pass
        # post save actions if new instance is created,
        # do something with `instance` or another models
        # be careful about circular imports. \m/

和信号挂钩，

post_save.connect(post_save_user_actions, sender=MyModel)