答：在用户之间建立关系的最佳方法是什么？
并非所有用户生来都是平等的。 django-relationship 在任意用户之间创建任意关系，这可能不是您想要的。您真正想要的是将这种关系严格限制为Seller -> Customer
# This example assumes that both customers and sellers have user table entries.
from django.contrib.auth.models import User
class Customer(User): pass
class Seller(User):
acquired_customers = ManyToManyField(Customer,
related_name="acquired_sellers")
def acquire(customer):
" A convenience function to acquire customers "
self.acquired_customers.add(customer.id)
B：在 Django 中与其他用户共享模型实例的最佳方法是什么？
您可以使用ManyToManyField 的自定义“直通”模型来添加要跟踪的额外信息。在这种情况下，我们添加了卖家，以及共享时的自动时间戳。这使您可以执行一些操作，例如显示与您共享的产品（按共享时间排序），以及向您发送产品的卖家名称。
# Install mptt for heirararchical data.
from mptt.models import MPTTModel
class Box(MPTTModel):
" Nestable boxen for your Items "
owner = ForeignKey(Seller)
title = CharField(max_length=255)
shared_with = ManyToManyField(Customer,
related_name='boxes_sharedwithme', through=SharedBox)
class Item(Model):
" A shareable Item "
box = ForeignKey(Box)
title = CharField(max_length=255)
class SharedBox(Model):
" Keeps track of who shares what to whom, and when "
when = DateTimeField(auto_now_add=True)
box = ForeignKey(Box)
seller = ForeignKey(Seller)
customer = ForeignKey(Customer)
#----------------------------
# share an Item with a Customer
def share_item(request, box_id, customer_id, **kwargs):
# This will fail if the user is not a seller
seller = request.user.seller
# This will fail if the seller is not the owner of the item's box
box = Box.objects.get(
id=box_id, owner=seller)
# This will fail if the seller has not acquired the customer
customer = Customer.objects.get(
id=customer_id, acquired_sellers=seller)
# This will share the item if it has not already been shared.
SharedBox.objects.create_or_update(
box=box, seller=seller, customer=customer)
return HttpResponse("OK")
C：如果我只共享 Box 模型，是否意味着它的所有相关模型（#Foreign 模型的 Box 模型）也将被共享？
隐式权限是“业务逻辑”，这意味着您可能需要自己实现它。幸运的是，Django 的权限系统是可插入的，因此您可以添加自己的规则来递归层次结构以检查权限。或者，您可以创建自定义管理器，将适当的规则添加到使用的查询中。
from django.db.models import Manager
from django.db.models.query import EmptyQuerySet
class ItemManager(Manager):
def visible(user):
iqs = self.get_query_set()
oqs = EmptyQuerySet()
# add all the items a user can see as a seller
try: oqs |= iqs.filter(box__owner=user.seller)
except Seller.DoesNotExist: pass
# add all the items a user can see as a customer
try: oqs |= iqs.filter(box__shared_with=user.customer)
except Customer.DoesNotExist: pass
# return the complete list of items.
return oqs
class Item(Model): objects = ItemManager()
class ItemListView(ListView):
model = Item
def get_queryset(request):
return self.model.objects.visible(request.user)
D：控制每个用户的字段级别权限的最佳方法是什么？
如果这需要超级粒度或每个用户，那么 django-guardian 是要走的路。如果权限是基于规则的，那么您最好使用一个简单的字段，以降低数据库查询的复杂性。
class Property(Model):
title = CharField(max_length=255)
units = CharField(max_length=10,
choices=UNIT_TYPES, null=True, blank=True)
# -- A simple field that toggles properties for all users
class ItemProperty(Model):
item = ForeignKey(Item)
property = ForeignKey(Property)
value = CharField(max_length=100)
customer_viewable = BooleanField(default=False)
customer_editable = BooleanField(default=False)
# -- A simple field that defines user classes who can view/edit
from django.contrib.auth.models import Group
class ItemProperty(Model):
item = ForeignKey(Item)
property = ForeignKey(Property)
value = CharField(max_length=100)
viewable_by = ForeignKey(Group)
editable_by = ForeignKey(Group)
免责声明：这些是我对这个主题的看法。 Django 社区中关于授权的观点非常分散。永远不会有一种“最佳”方式来做任何事情，因此请仔细考虑您是否需要真正通用的东西并且能够承受数据库命中，或者您是否需要快速和特定于业务的东西并且能够承受失去灵活性的代价。