Django中decorators裝飾器的使用

1、CBV實現的登錄視圖

class LoginView(View):

    def get(self, request):
        """
        處理GET請求
        """
        return render(request, 'login.html')

    def post(self, request):
        """
        處理POST請求 
        """
        user = request.POST.get('user')
        pwd = request.POST.get('pwd')
        if user == 'alex' and pwd == "alex1234":
            next_url = request.GET.get("next")
            # 生成隨機字符串
            # 寫瀏覽器cookie -> session_id: 隨機字符串
            # 寫到服務端session：
            # {
            #     "隨機字符串": {'user':'alex'}
            # }
            request.session['user'] = user
            if next_url:
                return redirect(next_url)
            else:
                return redirect('/index/')
        return render(request, 'login.html')

2、要在CBV視圖中使用我們上面的check_login裝飾器，有以下三種方式：

2.1、加在CBV視圖的get或post方法上

from django.utils.decorators import method_decorator


class HomeView(View):

    def dispatch(self, request, *args, **kwargs):
        return super(HomeView, self).dispatch(request, *args, **kwargs)

    def get(self, request):
        return render(request, "home.html")
    
    @method_decorator(check_login)
    def post(self, request):
        print("Home View POST method...")
        return redirect("/index/")

2.2、加在dispatch方法上

from django.utils.decorators import method_decorator


class HomeView(View):

    @method_decorator(check_login)
    def dispatch(self, request, *args, **kwargs):
        return super(HomeView, self).dispatch(request, *args, **kwargs)

    def get(self, request):
        return render(request, "home.html")

    def post(self, request):
        print("Home View POST method...")
        return redirect("/index/")

　　因為CBV中首先執行的就是dispatch方法，所以這么寫相當於給get和post方法都加上了登錄校驗。

2.3、直接加在視圖類上，但method_decorator必須傳 name 關鍵字參數

　　如果get方法和post方法都需要登錄校驗的話就寫兩個裝飾器。

from django.utils.decorators import method_decorator

@method_decorator(check_login, name="get")
@method_decorator(check_login, name="post")
class HomeView(View):

    def dispatch(self, request, *args, **kwargs):
        return super(HomeView, self).dispatch(request, *args, **kwargs)

    def get(self, request):
        return render(request, "home.html")

    def post(self, request):
        print("Home View POST method...")
        return redirect("/index/")

3、CSRF Token相關裝飾器在CBV中的使用

　　CSRF Token相關裝飾器在CBV只能加到dispatch方法上，或者加在視圖類上然后name參數指定為dispatch方法。

• csrf_protect，為當前函數強制設置防跨站請求偽造功能，即便settings中沒有設置全局中間件。
• csrf_exempt，取消當前函數防跨站請求偽造功能，即便settings中設置了全局中間件。

　　

from django.views.decorators.csrf import csrf_exempt, csrf_protect
from django.utils.decorators import method_decorator


class HomeView(View):

    @method_decorator(csrf_exempt)
    def dispatch(self, request, *args, **kwargs):
        return super(HomeView, self).dispatch(request, *args, **kwargs)

    def get(self, request):
        return render(request, "home.html")

    def post(self, request):
        print("Home View POST method...")
        return redirect("/index/")

　　或者

from django.views.decorators.csrf import csrf_exempt, csrf_protect
from django.utils.decorators import method_decorator


@method_decorator(csrf_exempt, name='dispatch')
class HomeView(View):
   
    def dispatch(self, request, *args, **kwargs):
        return super(HomeView, self).dispatch(request, *args, **kwargs)

    def get(self, request):
        return render(request, "home.html")

    def post(self, request):
        print("Home View POST method...")
        return redirect("/index/")