# Application definition

INSTALLED_APPS = [
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'Xadmin.apps.XadminConfig',
 'blogs.apps.BlogsConfig',
 'bigs.apps.BigsConfig',
]

from django.contrib.admin.sites import AdminSite, site
from django.utils.module_loading import autodiscover_modules

def autodiscover():
 autodiscover_modules('admin', register_to=site)

class AdminSite(object):
 """
 An AdminSite object encapsulates an instance of the Django admin application, ready
 to be hooked in to your URLconf. Models are registered with the AdminSite using the
 register() method, and the get_urls() method can then be used to access Django view
 functions that present a full admin interface for the collection of registered
 models.
 """
 def __init__(self, name='admin'):
 self._registry = {} # model_class class -> admin_class instance
 self.name = name
 # 关于register的方法
 def register(self, model_or_iterable, admin_class=None, **options):
 if not admin_class:
  admin_class = ModelAdmin
 # Instantiate the admin class to save in the registry
 self._registry[model] = admin_class(model, self)
 #备注：截取的源码中的一部分 

class ModelAdmin(BaseModelAdmin):
 "Encapsulates all admin options and functionality for a given model."

 list_display = ('__str__',)
 list_display_links = ()
 list_filter = ()
 list_select_related = False
 list_per_page = 100
 list_max_show_all = 200
 list_editable = ()
 search_fields = ()
 date_hierarchy = None
 save_as = False
 save_as_continue = True
 save_on_top = False
 paginator = Paginator
 preserve_filters = True
 inlines = []

 # Custom templates (designed to be over-ridden in subclasses)
 add_form_template = None
 change_form_template = None
 change_list_template = None
 delete_confirmation_template = None
 delete_selected_confirmation_template = None
 object_history_template = None
 popup_response_template = None

 # Actions
 actions = []
 action_form = helpers.ActionForm
 actions_on_top = True
 actions_on_bottom = False
 actions_selection_counter = True
 checks_class = ModelAdminChecks

 def __init__(self, model, admin_site):
 self.model = model
 self.opts = model._meta
 self.admin_site = admin_site
 super(ModelAdmin, self).__init__()

 def __str__(self):
 return "%s.%s" % (self.model._meta.app_label, self.__class__.__name__)

# 使用model代指模型类的类名
model._meta.model_name #得到字符串格式的类名（全小写的）
model._meta.app_label #可以得到当前类所在APP的字符串的名字
# 补充
model._meta.get_field("字符串格式的字段属性") # 得到一个字段属性的对象field_obj，这样我们就可以利用这个字段对象取得属性　　　　　　　　　　　　　　　　　　　　　　　　　　　# 比如： field_obj.verbose_name 

from django.conf.urls import url

from django.contrib import admin

def get_urls_operate():
 emp = []
 emp.append(url(r'^$',查询页面的视图函数))
 emp.append(url(r'^add/$',添加页面的视图函数))
 emp.append(url(r'^(\d+)/change/$',编辑页面的视图函数))
 emp.append(url(r'^(\d+)/delete/$',删除页面的视图函数))
 return emp


def get_urls():
 temp = []
 for model,main_class_obj in admin.site._registry.items():
 app_name = model._meta.app_label
 model_name = model._meta.model_name
 temp.append(url(r'^{}/{}/'.format(app_name,model_name),(get_urls_operate(),None,None))) #实现第二层路由的分发
 return temp

urlpatterns = [
 url(r'^Xadmin/',(get_urls(),None,None)) #自定义一个前缀 实现第一层路由的分发
]

from django.apps import AppConfig
class BlogsConfig(AppConfig):
 name = 'blogs'

MODELS_MODULE_NAME = 'models'
class AppConfig(object):
 """
 Class representing a Django application and its configuration.
 """
 def __init__(self, app_name, app_module):
 # Full Python path to the application eg. 'django.contrib.admin'.
 self.name = app_name

 def ready(self):
 """
 Override this method in subclasses to run code when Django starts.
　　　　#这句话的语义为：在子类中重写此方法，以便在Django启动时运行代码
 """

from django.apps import AppConfig
from django.utils.module_loading import autodiscover_modules
class XadminConfig(AppConfig):
 name = 'Xadmin'
 def ready(self):
  autodiscover_modules('Xadmin') #Django启动时会自动扫描每个app下的Xadmin.py文件

from blogs import models
from Xadmin.service.Xadmin import site
site.register(models.UserInfo)
site.register(models.Book)

from django.conf.urls import url
from django.shortcuts import HttpResponse,render
class ModelXadmin(object):
 def __init__(self,model,site):
  self.model = model
  self.site = site
 def show(self,request):
  data_list = self.model.objects.all()
  return render(request,'show.html',locals()) #locals() 请函数内部所有的键值对存储 == {"data_list":data_list}
 def add(self,request):
  return HttpResponse('添加页面')
 def edit(self,request, pk):
  return HttpResponse('编辑页面')
 def delete(self,request, pk):
  return HttpResponse('删除页面')
 @property
 def get_urls_operate(self):
  emp = []
  emp.append(url(r'^$', self.show))
  emp.append(url(r'^add/$', self.add))
  emp.append(url(r'^(\d+)/change/$', self.edit))
  emp.append(url(r'^(\d+)/delete/$', self.delete))
  return emp
 @property
 def urls(self):
  return self.get_urls_operate,None,None
class XadminSite(object):
 def __init__(self,name='xadmin'):
  self._registry = {}
 def register(self,model,class_main=None,**option):
  if not class_main:
   class_main = ModelXadmin
  self._registry[model] = class_main(model,self)
 @property
 def get_urls(self):
  # print(admin.site._registry)
  temp = []
  for model, model_admin_object in self._registry.items():
   model_name = model._meta.model_name
   model_app = model._meta.app_label
   temp.append(url(r'^{}/{}/'.format(model_app, model_name), model_admin_object.urls))
  return temp
 @property
 def urls(self):
  return self.get_urls,None,None
site = XadminSite()