关于Django中登录认证的方式:

关于method_decorator的作用,以及不再使用method_decorator为装饰器,添加self

1.method_decorator的作用:

为函数视图装饰器补充第一个参数self,以适配类视图的方法;

如果装饰器本身就可以适配类视图的方法,就无须再使用method_decorator

def my_decorator(view_func):
	def wrapper(request,*args,**kwargs):
        print('装饰器被调用')
        print(request.path)
        return view_func(request,*args,**kwargs)
    return wrapper

#method_decorator装饰器为函数视图装饰器(就是wrapper)补充第一个self参数,以适配类视图方法
@method_decortaor(my_decorator,name='disatch')
class DemoView(View):
    def get(self,request):
        return HttpResponse('aaa')
    def post(self,request):
        return HttpResponse('bbb')

我们可以自己补充self,就不再使用method_decorator

def my_decorator(view_func):
    def wrapper(self,request,*args,**kwargs):
        print('装饰器被调用')
        print(request.path)
        return view_func(self,request,*args,**kwargs)
    return wrapper

@my_decorator
class DemoView(View):
    def get(self,request):
        return HttpResponse('aaa')
    def post(self,request):
        return HttpResponse('bbb')

def check_ip(func):
    #实现禁止ip黑名单访问发帖界面.可以通过在视图函数使用装饰器实现
    def wrapper(request,*args,**kwargs):
        #禁止ip黑名单访问
        IP = request.META.get('REMOTE_ADDR')
        if IP in ['192.168.168.11']:
            return HttpResponse("此IP禁止访问")
        return func(request,*args,**kwargs)
    return wrapper

补充一个login_required -- 登录验证装饰器:

源码:

def login_required(function=None, redirect_field_name=REDIRECT_FIELD_NAME, login_url=None):
    """
    Decorator for views that checks that the user is logged in, redirecting
    to the log-in page if necessary.
    """
    actual_decorator = user_passes_test(
        lambda u: u.is_authenticated,
        login_url=login_url,
        redirect_field_name=redirect_field_name
    )
    if function:
        return actual_decorator(function)
    return actual_decorator

# user_passes_test源码
def user_passes_test(test_func, login_url=None, redirect_field_name=REDIRECT_FIELD_NAME):
    """
    Decorator for views that checks that the user passes the given test,
    redirecting to the log-in page if necessary. The test should be a callable
    that takes the user object and returns True if the user passes.
    """

    def decorator(view_func):
        @wraps(view_func)
        def _wrapped_view(request, *args, **kwargs):
            if test_func(request.user):
                return view_func(request, *args, **kwargs)
            path = request.build_absolute_uri()
            resolved_login_url = resolve_url(login_url or settings.LOGIN_URL)
            # If the login url is the same scheme and net location then just
            # use the path as the "next" url.
            login_scheme, login_netloc = urlparse(resolved_login_url)[:2]
            current_scheme, current_netloc = urlparse(path)[:2]
            if ((not login_scheme or login_scheme == current_scheme) and
                    (not login_netloc or login_netloc == current_netloc)):
                path = request.get_full_path()
            from django.contrib.auth.views import redirect_to_login
            return redirect_to_login(
                path, resolved_login_url, redirect_field_name)
        return _wrapped_view
    return decorator


#1.直接在类的视图中写登录校验实现:
"""
Django用户认证系统提供了request.user.is-authenticated()来判断用户是否登录,如果登录返回True,反之,返回False;

缺点:登录认证逻辑需要地方太多,代码重复多次
"""
class UserInfoView(View):
    '''用户中心'''
    def get(self,request):
        '''个人信息界面'''
        if request.user.is_authenticated():
            return render(request,'user_center_info.html')
        else:
            return redirect(reverse('users:login'))

        
#2.1(URLconf装饰使用方法)对路由中的as_view()使用装饰器:login_required
'''在定义路由时添加:'''
url(r'^info/$',login_required(views.UserinfoView.as_view()),name='info')

#2.2装饰基于函数的视图
from django.contrib.auth.decorators import login_required
from django.http import HttpResponse

@login_required
def my_view(request):
    if request.method == 'GET':
        return HttpResponse('result')
    
#2.3装饰类的视图
from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
from django.views.generic import TemplateView

class ProtectedView(TempalteView):
    template_name = 'secret.html'
    @method_decorator(login_required)
    def dispatch(self,*args,**kwargs):
        return super(ProtectedView,self).dispatch(*args,**kwargs)
    
    
# 2.4 装饰通过Mixin类继承来实现:
from django.contrib.auth.decorators import login-required
from django.http import HttpResponse
from django.shortcuts import render
from django.views.generic import View
from .forms import MyForm

class LoginRequiredMixin(object):
    @classmethod
    def as_view(cls,**kwargs):
        view == super(LoginRequiredMixin,cls).as_view(**initkwargs)
        return login_required(view)
    
    
class MyFormView(LoginRequiredMixin,View):
    form_class = MyForm
    initial = {'key':'value'}
    template_name = 'form_template.html'
    
    def get(self,request,*args,**kwargs):
        form = self.form_class(initial = self.initial)
        return render(request,self.template_name,{'form':form})
    

#3.定义验证用户是否登录扩展类
'''使用Django自带的login_required装饰器来完成扩展,完成扩展后需要该功能的视图只需多继承该类就可以,复用率很高'''

#自定义的工具目录:
from django.contrib.auth.decorator import login_required

class LoginRequiredMinxin(object):
    @classmethod
    def as_view(cls,**kwargs):
        view = super().as_view(**kwargs)
        return login_required(view)
#使用时导包,并同时继承自定义类LoginRequiredMixin和View即可:
class UserInfoView(LoginRequiredMixin,View):
    '''用户中心'''
    def get(self,request):
        '''个人信息页面'''
        return render(request,'user_center_info.html')

    
'''
3.1装饰器login_required会自带next参数,和重定向地址,用于登陆后跳转以及不满足登录状态的重定向地址;
3.2 如果未设置登录验证则被重定向到LOGIN_URL配置(settings.py)项指定的地址;
3.3 在设置文件添加如下配置:表示当前用户未通过登录验证时,将用户重定向到/login/登录页面,LOGIN_URL = '/login/'
3.4 若不设置,默认未通过的登录验证时跳转路径是:/account/login/
3.5 跳转后的next参数,帮助用户完成登录后,自动跳转回登录前的页面


'''