Question

我一直在尝试在项目中使用FieldTracker来跟踪从post_save信号中更新的字段。最初，我考虑使用django-dirtyfields，但是由于它不支持django 2.1，因此我不得不求助于django-model-utils。

下面是项目设置

customer / apps.py

from django.apps import AppConfig

class CustomerConfig(AppConfig):
    name = 'customer'

    def ready(self):
        import customer.signals

customer / models.py

from model_utils import FieldTracker

class CreatedByModel(models.Model):
    created_by = models.ForeignKey(User, blank=True, null=True)
    modified_by = models.ForeignKey(User, blank=True, null=True)

    class Meta:
        abstract = True

class Customer(CreatedByModel)
    name = models.CharField(max_length=255)
    code = models.CharField(max_length=10)

    customer_tracker = FieldTracker()

在此处包括管理save_model代码，因为我在此处明确设置了created_by和modified_by字段，并调用了超类save_model，但我不确定这可能引起问题

customer / admin.py

class CustomerAdmin(admin.ModelAdmin):

    def save_model(self, request, obj, form, change):
        if not obj.created_by:
            obj.created_by = request.user
        else:
            obj.modified_by = request.user
        super().save_model(request, obj, form, change)

customer / signals.py

from django.db.models.signals import post_save
from django.dispatch import receiver

from .models import Customer

@receiver(post_save, sender=Customer)
def notify_api_clients(sender, **kwargs):
    print('hit inside tracker {}' . format(sender.customer_tracker.changed()))

我在尝试保存说明AttributeError的Customer对象时收到'FieldTracker' object has no attribute 'changed'错误。

我不确定这里可能是什么问题。感谢任何指导。

更新经过几次测试，我可以使用post_save自变量**kwargs中的实例调用它，然后按以下方法获取changed（）字段

@receiver(post_save, sender=Customer)
def notify_api_clients(sender, **kwargs):
    if 'instance' in kwargs:
        instance = kwargs['instance']
        print('changed fields: {}' . format(instance.customer_tracker.changed()))

我希望这可能是我所缺少的。

FieldTracker试图获取change（）字段时在post_save信号中抛出AttributeError

0 个答案: