django-admin的源码流程

django-admin的源码流程

 一、admin的源码流程

首先可以确定的是：路由关系一定对应一个视图函数

a、当点击运行的时候，会先找到每一个app中的admin.py文件，并执行

b、执行urls.py 

admin.site是什么？

admin.site,urls    返回的是一个元组，里面的第一个元素是一个列表

django-admin的源码流程
我们自己生成的动态的访问url
====================================初级版=========================
from django.shortcuts import HttpResponse
from django.conf.urls import url
from django.contrib import admin
from app01 import views
def login(request):
    return HttpResponse("ok")
url_list = []
for model_class,v in admin.site._registry.items():

print(model_class)  #打印的是每一个类<class 'app01.models.UserInfo'>

cls_name = model_class._meta.model_name #当前类名称的小写

app_name = model_class._meta.app_label  #当前app的名称

val = url(r'^{0}/{1}/$'.format(app_name,cls_name), login, name="login")

url_list.append(val)
urlpatterns = [

url(r'^admin/', admin.site.urls),

# admin.site这个对象里面有一个属性_registry = {}

#点击urls查看源码返回的是一个元组，元组的第一个元素是一个列表

url(r'^index/', ([

url(r'^app01/userinfo/$', login,name="login"),

url(r'^app01/roles/$', login,name="login"),

],None,None)),
url(r</span><span style="color: #800000;">'</span><span style="color: #800000;">^index2/</span><span style="color: #800000;">'</span>, (url_list,None,None,)),  <span style="color: #008000;">#</span><span style="color: #008000;">吧上面定义的列表拿下来，这是后就动态生成了</span>

]

================================升级============================
路径http://127.0.0.1:8001/index/app01/roles/后面还有增删改查的路径
http://127.0.0.1:8001/index/app01/roles/add/
http://127.0.0.1:8001/index/app01/roles/1/change/
http://127.0.0.1:8001/index/app01/roles/1/del/
实现流程

from django.shortcuts import HttpResponse

from django.conf.urls import url

from django.contrib import admin

from app01 import views

def login(request):

return HttpResponse("ok")
def change_list(request):

return HttpResponse("列表页面")
def add_view(request):

return HttpResponse("添加页面")
def change_view(request,nid):

return HttpResponse("修改页面")
def delete_view(request,nid):

return HttpResponse("删除页面")
url_list = []
for model_class,v in admin.site._registry.items():

print(model_class)  #打印的是每一个类<class 'app01.models.UserInfo'>

cls_name = model_class._meta.model_name #当前类名称的小写

app_name = model_class._meta.app_label  #当前app的名称

urls_list = url(r'^{0}/{1}/$'.format(app_name,cls_name), change_list, name="login")

url_list.append(urls_list)
add_url </span>= url(r<span style="color: #800000;">'</span><span style="color: #800000;">^{0}/{1}/add/$</span><span style="color: #800000;">'</span>.format(app_name, cls_name), add_view, name=<span style="color: #800000;">"</span><span style="color: #800000;">login</span><span style="color: #800000;">"</span><span style="color: #000000;">)
url_list.append(add_url)

change_url </span>= url(r<span style="color: #800000;">'</span><span style="color: #800000;">^{0}/{1}/(d+)/change/$</span><span style="color: #800000;">'</span>.format(app_name, cls_name), change_view, name=<span style="color: #800000;">"</span><span style="color: #800000;">login</span><span style="color: #800000;">"</span><span style="color: #000000;">)
url_list.append(change_url)

del_url </span>= url(r<span style="color: #800000;">'</span><span style="color: #800000;">^{0}/{1}/(d+)/del/$</span><span style="color: #800000;">'</span>.format(app_name, cls_name), delete_view, name=<span style="color: #800000;">"</span><span style="color: #800000;">login</span><span style="color: #800000;">"</span><span style="color: #000000;">)
url_list.append(del_url)

urlpatterns = [

url(r'^admin/', admin.site.urls),

# admin.site这个对象里面有一个属性_registry = {}

#点击urls查看源码返回的是一个元组，元组的第一个元素是一个列表

url(r'^index/', (

[

url(r'^app01/userinfo/$', login,name="login"),

url(r'^app01/roles/$', login,name="login"),

],None,None)),

url(r'^index2/', (url_list,None,None,)),  #吧上面定义的列表拿下来，这是后就动态生成了

]
说明了：

url的本质：它读取_registry所有字典里面的数据，为字典里面的每一个类生成了4个url

==================================修改上面的版本=============================
定义了一个
def get_urls():
    temp = [
        url(r'^$'.format(app_name, cls_name), change_list),
        url(r'^add/$'.format(app_name, cls_name), add_view),
        url(r'^del/$'.format(app_name, cls_name), delete_view),
        url(r'^change/$'.format(app_name, cls_name), change_view)
    ]
    return temp
url_list = []

for model_class,v in admin.site._registry.items():

print('-------',model_class)  #打印的是每一个类<class 'app01.models.UserInfo'>

cls_name = model_class._meta.model_name #当前类名称的小写

app_name = model_class._meta.app_label  #当前app的名称

    方式一：

# all_urls = url(r'^{0}/{1}/'.format(app_name,cls_name), (get_urls(),None,None,))

    方式二：

all_urls = url(r'^{0}/{1}/'.format(app_name,cls_name), include(get_urls()) )

url_list.append(all_urls)
urlpatterns = [

url(r'^admin/', admin.site.urls),

# admin.site这个对象里面有一个属性_registry = {}

#点击urls查看源码返回的是一个元组，元组的第一个元素是一个列表

url(r'^index/', (

[

url(r'^app01/userinfo/', ([

url(r'^$', change_list, name="login"),

url(r'^add/$', add_view, name="login"),

url(r'^(d+)/del/$', delete_view, name="login"),

url(r'^(d+)/change/$', change_view, name="login"),

],None,None),name="login"),

url(r'^app01/usertype/', ([

url(r'^$', change_list, name="login"),

url(r'^add/$', add_view, name="login"),

url(r'^(d+)/del/$', delete_view, name="login"),

url(r'^(d+)/change/$', change_view, name="login"),

], None, None), name="login"),],None,None)),

url(r'^app02/article/', ([

url(r'^$', change_list, name="login"),

url(r'^add/$', add_view, name="login"),

url(r'^(d+)/del/$', delete_view, name="login"),

url(r'^(d+)/change/$', change_view, name="login"),

],None,None),name="login"),
</span><span style="color: #008000;">#</span><span style="color: #008000;"> index和index2的两个是一样的，我们可以用index2的方式替代index</span>
url(r<span style="color: #800000;">'</span><span style="color: #800000;">^index2/</span><span style="color: #800000;">'</span>, (url_list,None,None,)),  <span style="color: #008000;">#</span><span style="color: #008000;">吧上面定义的列表拿下来，这是后就动态生成了</span>

]
include的本质就是：返回了一个元组，元组的第一个是这个模块

include里面

既可以写一个列表include([])，利用include做分发

也可以返回一个字符串：帮我们去找到这个模块，找到所有的映射关系
include(model_admin.urls)

model_admin是什么？ModelAdmin对象的urls

总结

- admin源码流程
        a. 运行程序，找到每一个app中的 admin.py 文件，并加载
            - app01.admin.py 
                - 创建admin.site中的对象
                - 执行对象的 register方法，目的：将注册类添加到 _registry中 
                    _registry = {  
                        key是传进来的model   value:是ModelAdmin的对象，传了两个参数
                        models.Role: ModelAdmin(models.Role,admin.site),
                        models.UserInfo: ModelAdmin(models.UserInfo,admin.site)
                        models.UserType: ModelAdmin(models.UserType,admin.site)
                    }
        </span>-<span style="color: #000000;"> app02.admin.py
            </span>-<span style="color: #000000;"> 用app01.admin中创建那个admin.site对象
            </span>-<span style="color: #000000;"> 执行对象的 register方法，目的：讲注册类添加到 _registry中 
                _registry </span>=<span style="color: #000000;"> {
                    models.Role: ModelAdmin(models.Role,admin.site),
                    models.UserInfo: ModelAdmin(models.UserInfo,admin.site)
                    models.UserType: ModelAdmin(models.UserType,admin.site)
                    models.Article: ModelAdmin(models.Article,admin.site)
                }
    
        admin.site是一个对象（单例模式创建），其中封装了： 
            _registry </span>=<span style="color: #000000;"> {
                models.Role: ModelAdmin(models.Role,admin.site),
                models.UserInfo: ModelAdmin(models.UserInfo,admin.site)
                models.UserType: ModelAdmin(models.UserType,admin.site)
                models.Article: ModelAdmin(models.Article,admin.site)
            }
    b. urls.py 
        再次调用 admin.site 对象的 urls属性：
            urlpatterns </span>=<span style="color: #000000;"> [
                url(r</span><span style="color: #800000;">'</span><span style="color: #800000;">^admin/</span><span style="color: #800000;">'</span><span style="color: #000000;">, admin.site.urls),
            ]
        
        </span><span style="color: #0000ff;">class</span><span style="color: #000000;"> ModelAdmin(object):
            </span><span style="color: #0000ff;">def</span> <span style="color: #800080;">__init__</span><span style="color: #000000;">(self,model_class,site):
                self.model_class </span>=<span style="color: #000000;"> model_class
                self.site </span>=<span style="color: #000000;"> site 
                
            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> changelist_view(self,request):
                data_list </span>= self.model_class.objects.all()   <span style="color: #008000;">#</span><span style="color: #008000;">是动态的</span>
                <span style="color: #0000ff;">return</span> HttpResponse(<span style="color: #800000;">'</span><span style="color: #800000;">列表页面</span><span style="color: #800000;">'</span><span style="color: #000000;">)

            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> add_view(self,request):
                </span><span style="color: #0000ff;">return</span> HttpResponse(<span style="color: #800000;">'</span><span style="color: #800000;">添加页面</span><span style="color: #800000;">'</span><span style="color: #000000;">)


            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> delete_view(self,request,nid):
                </span><span style="color: #0000ff;">return</span> HttpResponse(<span style="color: #800000;">'</span><span style="color: #800000;">删除页面</span><span style="color: #800000;">'</span><span style="color: #000000;">)

            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> change_view(self,request,nid):
                </span><span style="color: #0000ff;">return</span> HttpResponse(<span style="color: #800000;">'</span><span style="color: #800000;">修改页面</span><span style="color: #800000;">'</span><span style="color: #000000;">)
            
            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> get_urls(self):
                 urlpatterns </span>=<span style="color: #000000;"> [
                    url(r</span><span style="color: #800000;">'</span><span style="color: #800000;">^$</span><span style="color: #800000;">'</span><span style="color: #000000;">, self.changelist_view),
                    url(r</span><span style="color: #800000;">'</span><span style="color: #800000;">^add/$</span><span style="color: #800000;">'</span><span style="color: #000000;">, self.add_view),
                    url(r</span><span style="color: #800000;">'</span><span style="color: #800000;">^(.+)/delete/$</span><span style="color: #800000;">'</span><span style="color: #000000;">, self.delete_view),
                    url(r</span><span style="color: #800000;">'</span><span style="color: #800000;">^(.+)/change/$</span><span style="color: #800000;">'</span><span style="color: #000000;">, self.change_view),
                ]
                </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> urlpatterns
            
            @property 
            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> urls(self):
                </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> self.get_urls()
            
        
        </span><span style="color: #0000ff;">class</span><span style="color: #000000;"> AdminSite(object):
            </span><span style="color: #0000ff;">def</span> <span style="color: #800080;">__init__</span><span style="color: #000000;">(self):
                self._registry </span>=<span style="color: #000000;"> {}
                
            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> register(self,model_class,model_admin):
                self._registry[model_class] </span>=<span style="color: #000000;"> model_admin(model_class,self)
            
            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> get_urls(self):
                </span><span style="color: #800000;">"""</span><span style="color: #800000;">
                models.Role: ModelAdmin(models.Role,admin.site),
                models.UserInfo: ModelAdmin(models.UserInfo,admin.site)
                models.UserType: ModelAdmin(models.UserType,admin.site)
                models.Article: ModelAdmin(models.Article,admin.site)
                </span><span style="color: #800000;">"""</span><span style="color: #000000;">
                url_list </span>=<span style="color: #000000;"> []
                </span><span style="color: #0000ff;">for</span> model_class,model_admin <span style="color: #0000ff;">in</span><span style="color: #000000;"> self._registry.items():
                    model_class是一个类
                    app_name </span>=<span style="color: #000000;"> model_class._meta.app_label
                    model_name </span>=<span style="color: #000000;"> model_class._meta.model_name 
                    url_list </span>+=<span style="color: #000000;"> [
                        url(</span><span style="color: #800000;">'</span><span style="color: #800000;">%s/%s</span><span style="color: #800000;">'</span> %<span style="color: #000000;">(app_name,model_name,), include(model_admin.urls))
                    ]
                    
                </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> url_list
                    
            
            @property
            </span><span style="color: #0000ff;">def</span><span style="color: #000000;"> urls(self):
                </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> (self.get_urls(), None,None )
        </span></pre>