Django之admin
一、admin简介
admin为Django提供的后台管理工具，可以通过“http://127.0.0.1:8000/admin/”进行访问，访问是需要用户名和密码（可以在创建的Django项目命令行下创建 “python manage.py createsuperuser” ）
如果想在后台看到admin管理的对象（数据对象），首先要在Django所创建的app中的admin.py注册数据对象，代码如下：
class BookConfig(admin.ModelAdmin):
def deletes(self):
return mark_safe("<a href=''>删除</a>")
list_display = ["title","publish","publishDate","price",deletes]
#list_display_links = ["title","publish","publishDate","price",]
list_display_links = ["publish", "publishDate", "price", ]
list_filter = ["price","authors","publish",]
list_editable = ["title",]
search_fields = ["title", "price"]
def patch_init(self,request,queryset):
queryset.update(price=100)
patch_init.short_description = "批量初始化"
actions = [patch_init,]
#change_list_template = "list.html"
fields = ("title",)
admin.site.register(models.Book,BookConfig)
admin.site.register(models.AuthorDetail)
admin.site.register(models.Author)
红色部分为正常注册，如果需要向admin界面中添加更多功能(样式)，则需要在配置是加入第二个参数：配置类（代码蓝色--样式类），配置类需要继承admin.ModelAdmin类，具体参数配置可以查看admin.ModelAdmin源码
二、Admin的实现流程：
1、启动；
当Django启动时，程序扫描setting.py，加载INSTALLED_APPS下的每个app，加载django.contrib.admin时，django.contrib.admin下的autodiscover方法自动扫描加载每个app下的admin.py文件
def autodiscover():
autodiscover_modules('admin', register_to=site)
2、注册；
admin.site(单例对象)
admin.site.register(模型对象)
#源代码解析
class AdminSite(object): ...... def __init__(self, name='admin'): self._registry = {} ...... def register(self, model, admin_class=None, **options): if not admin_class: admin_class = ModelAdmin ...... self._registry[model] = admin_class(model, self) # {Book:ModelAdmin(Book)} #admin.site.register(Book) #admin.site._registry={Book:ModelAdmin(Book)} #admin.site.register(Publish) #admin.site._registry={Book:ModelAdmin(Book),Publish:ModelAdmin(Publish)} #class Authoconfig(admin.ModelAdmin): pass admin.site.register(Author,Authoconfig) # admin.site._registry={Book:ModelAdmin(Book),Publish:ModelAdmin(Publish),Author:Authoconfig(Author)}
3、设计URL
在此以模型类Book为例，每一个app下的模型类，后台管理提供增删改查四个url：
127.0.0.1:8000/admin/app01/book/
127.0.0.1:8000/admin/app01/book/add/
127.0.0.1:8000/admin/app01/book/1/change/
127.0.0.1:8000/admin/app01/book/1/delete/
Django内部实现：
path('admin/', admin.site.urls)#实现所有模型类的增删改查url的分发
下面为自定义URL分发(当然，你也可以自己尝试重构admin的url分发，原理是一样的)
from django.contrib import admin
from django.urls import path
from django.conf.urls import url
from app01 import views
from django.shortcuts import HttpResponse
def get_urls2():
temp=[]
temp.append(url(r"^$",views.list_view))
temp.append(url(r"^add/$", views.add_view))
temp.append(url(r"^(\d+)/change/$", views.change_view))
temp.append(url(r"^(\d+)/delete/$", views.delete_view))
return temp
def get_urls():
#print(admin.site._registry)
temp=[]
for model,admin_class_obj in admin.site._registry.items():#admin.site._registry.items（所有注册过的模型类）
#model对应模型类，admin_class_obj 对应自定义样式类
app_name=model._meta.app_label
model_name=model._meta.model_name
print(app_name,model_name)
temp.append(url(r'^{0}/{1}/'.format(app_name,model_name),(get_urls2(),None,None)),)
return temp
urlpatterns = [
path('admin/', admin.site.urls),
url(r'^Xadmin/',(get_urls(),None,None)),
]
4、Xadmin注册
下面是关于Xadmin，Xadmin其实是自定义的admin，通过以上对admin源码的分析，我们可以自己构造出admin——Xadmin。
Xadmin注册流程：
1）新建Django项目，创建名为Xadmin的app；
2）在Xadmin中创建Xadmin，代码如下：
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 list_view(self, request):
print(self.model)
data_list=self.model.objects.all()
return render(request, "list_view.html",{"data_list":data_list})
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")
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
@property
def urls2(self):
return self.get_urls2(), None, None
class XadminSite(object):
def __init__(self,name="admin"):
self._registry={}
def get_urls(self):
temp = []
for model, admin_class_obj in self._registry.items():
app_name = model._meta.app_label
model_name = model._meta.model_name
temp.append(url(r'^{0}/{1}/'.format(app_name, model_name), admin_class_obj.urls2), )
return temp
@property
def urls(self):
return self.get_urls(), None, None
def register(self,model,admin_class=None,**options):
if not admin_class:
admin_class=ModelXadmin
self._registry[model]=admin_class(model,self)
site=XadminSite()#基于模块的单例对象
首先，仿照admin源码实现__init__和register方法；其次，实现url分发；最后，实例化一个单例对象。
使用，新建一个app，并新建一个Xadmin.py，将app的模型类在此Xadmin中注册，代码如下：
print("app01_Xadmin")
from app01.models import *
#自定义注册
site.register(Book)
site.register(Publish)
site.register(Author)
site.register(AuthorDetail)
#原始注册
#admin.site.register()
