看看下面的元实现,它为所有将 MyModelMeta Class 设置为元类的 django 模型添加了读取权限:
class MyModelMeta(ModelBase):
# add a read permission to each MyModelMeta model
def __new__(cls, name, bases, attrs):
Meta = None
if "Meta" in attrs:
Meta = attrs.get("Meta")
if hasattr(Meta, "abstract") and getattr(Meta, "abstract"):
# if the class is abstract, don't create permissions for it, just return the class object
return super(MyModelMeta, cls).__new__(cls, name, bases, attrs)
if not Meta:
# create a new Meta Class
Meta = type('Meta', (object,), {})
setattr(Meta, 'permissions',(("read_%s"%name.lower(), "Can read %s"%name.lower()),))
attrs['Meta'] = Meta
return super(MyModelMeta, cls).__new__(cls, name, bases, attrs)
创建一个抽象的 django 模型并将元类成员设置为 MyModelMeta:
class MyAbstractModel(models.Model):
__metaclass__ = MyModelMeta
class Meta:
abstract=True
现在,像这样创建一个普通的 django 模型:
class SomeModel(MyAbstractModel):
someFieldName = models.CharField(max_length=256, db_index=True)
这将生成默认的 add/change/delete_somemodel 权限,但也会添加新的 read_somemodel 权限。
如果您也在使用 south,请使用它来生成额外的权限:
from django.db.models import get_app, get_models
from django.contrib.auth.management import create_permissions
create_permissions(get_app(app), get_models(), 2 if settings.DEBUG else 0)