零、预备知识 单例对象
方式一：__new__方法
方式二：模块导入，只要在引入的文件中实例了这个对象，不管引道哪里，这个对象都指向同一个内存空间
class My_singleton(object):
def foo(self):
print("ok")
my_singleton = My_singleton()
from xxx import my_singleton my_singleton.foo()
一、Xadmin之注册与生成url
在Xadmin.apps中：
from django.apps import AppConfig
from django.utils.module_loading import autodiscover_modules
class XadminConfig(AppConfig):
name = 'Xadmin'
def ready(self): #调用这个类时自动执行
autodiscover_modules('Xadmin') #从admin.py文件中复制，读取每个app中Xadmin.py文件
在Xadmin.py中：
from django.conf.urls import re_path
from django.shortcuts import HttpResponse
class ModelXadmin(object):
def __init__(self,model,site):
self.model = model
self.site = site
def list_view(self,request): #查询界面
return HttpResponse("list_view")
def add_view(self,request): #增加界面
return HttpResponse("add_view")
def change_view(self,request,id): #修改界面
return HttpResponse("change_view")
def delete_view(self,request,id): #删除界面
return HttpResponse("delete_view")
@property
def urls(self):
temp = []
temp.append(re_path(r'^$',self.list_view))
temp.append(re_path(r'^add/$',self.add_view))
temp.append(re_path(r'^(\d+)/delete/$',self.delete_view))
temp.append(re_path(r'^(\d+)/change/$',self.change_view))
return temp,None,None
class XadminSite(object):
def __init__(self):
self._registry = {}
def register(self,model,Xadmin_class=None,**options):
if not Xadmin_class:
Xadmin_class = ModelXadmin
self._registry[model] = Xadmin_class(model,self) #{Book:ModelXadmin(Book)}
@property
def urls(self):
temp = []
for model,Xadmin_class in self._registry.items():
app_name = model._meta.app_label #取相应app的名字
model_name = model._meta.model_name #取相应model的名字
temp.append(re_path(r'^{0}/{1}/'.format(app_name,model_name),Xadmin_class.urls))#
return temp,None,None
site = XadminSite() #创建单例对象
在app的Xadmin.py中：
from Xadmin.service import Xadmin from app02 import models Xadmin.site.register(models.Food) Xadmin.site.register(models.Order)