INSTALLED_APPS = [
    ‘django.contrib.admin‘,
    ‘django.contrib.auth‘,
    ‘django.contrib.contenttypes‘,
    ‘django.contrib.sessions‘,
    ‘django.contrib.messages‘,
    ‘django.contrib.staticfiles‘,
    ‘Xadmin.apps.XadminConfig‘,     # 加载Xadmin下的apps.py里的XadminConfig类
    ‘app01.apps.App01Config‘,
    ‘app02.apps.App02Config‘,
]

from django.apps import AppConfig
from django.utils.module_loading import autodiscover_modules    

class XadminConfig(AppConfig):
    name = ‘Xadmin‘

    def ready(self):                     # 这个类被加载的时候会执行这个方法。
        autodiscover_modules(‘Xadmin‘)   # 自动发现并加载应用下所有Xadmin的模板

from django.conf.urls import url
from django.shortcuts import render, HttpResponse, redirect


# Xadmin流程回顾:1启动 2注册 3设计urls ! admin是为model服务的,所以注册的是model,设计的也是model的增删改查urls
# 一个py文件可以同时完成注册、设计urls


class ModelXadmin(object):
    def __init__(self, model, site):
        self.model = model
        self.site = site


    @property
    def urls2(self):
        return self.get_urls2(), None, None

    def get_urls2(self):
        temp = []

        temp.append(url(r"^$", self.list_view))
        temp.append(url(r"^add/$", self.add_view))
        temp.append(url(r"^(\d+)/change/$", self.change_view))
        temp.append(url(r"^(\d+)/delete/$", self.delete_view))

        return temp

    def list_view(self, request):
        all_obj = self.model.objects.all()
        return render(request, ‘list_view.html‘, {‘all_obj‘: all_obj})

    def add_view(self, request):
        return render(request, ‘add_view.html‘)

    def change_view(self, request, id):
        return render(request, ‘change_view.html‘)

    def delete_view(self, request, id):
        return render(request, ‘delete_view.html‘)


class XadminSite():
    def __init__(self):
        self._register = {}

    # ②注册model的函数,传入model和model的自定义类
    def register(self, model, admin_class=None, **options):
        if not admin_class:
            admin_class = ModelXadmin
        # ③key是model,设计url的时候取app名字和类名
        # values是样式对象,设计二级url,哪个model就设计哪个model的增删改查,然后就好取值了
        self._register[model] = admin_class(model, self)

    # ④ 开始设计model的增删改查url(r‘^Xadmin/‘, site.urls)
    @property
    def urls(self):
        return self.get_urls(), None, None

    # ⑤ 第一次url分发，它是什么样的？ /app01/book/  /app02/order/
    def get_urls(self):
        temp = []  # 肯定返回列表
        # ⑥ 循环self._register, key是model,value是样式对象
        for model, admin_class_obj in self._register.items():
            app_name = model._meta.app_label
            model_name = model._meta.model_name
            # ⑦ 第二次url分发
            temp.append(url(r‘^{0}/{1}/‘.format(app_name, model_name), admin_class_obj.urls2))
        return temp


# ①单例模式对象，所有app的model都使用这个对象注册
site = XadminSite()

from Xadmin.service.Xadmin import site
urlpatterns = [
    url(r‘^admin/‘,  admin.site.urls),
    url(r‘^Xadmin/‘, site.urls),
]