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python测试开发django-73.django视图 CBV 和 FBV

作者:互联网

前言

FBV(function base views) 就是在视图里使用函数处理请求,这一般是学django入门的时候开始使用的方式。
CBV(class base views) 就是在视图里使用类处理请求,这是面向对象的编程方式。

面试的时候基本上都是问到:你平常写的视图是基于函数的视图 (FBV),还是基于类的视图 (CBV),两者的区别在哪?
如果你只会写基于函数的视图,那说明还处于初级入门的阶段了。

FBV 模式

FBV(function base views)在views.py文件中定义视图函数来处理用户请求,函数中通过 if 判断 request.method 请求方式是 GET 还是 POST请求做对应的处理。

# views.py
from django.shortcuts import render
from django.http import HttpResponse, JsonResponse
# 上海-悠悠,QQ交流群:750815713
# Create your views here.

# function base views

def fbvdemo(request):
    '''function base views'''
    context = {
        "code": 0,
        "msg": ""
    }
    if request.method == "GET":
        context["msg"] = "这是fbvdemo get请求"
        return JsonResponse(context)

    if request.method == "POST":
        context["msg"] = "这是fbvdemo POST请求"
        return JsonResponse(context)

urls.py配置访问路径

from django.conf.urls import url

urlpatterns = [

    url(r'^fbvdemo/$', views.fbvdemo)
]
CBV 模式

CBV(class base views) 就是在视图里使用类处理请求

# views.py
from django.shortcuts import render
from django.http import HttpResponse, JsonResponse

# Create your views here.
# 上海-悠悠,QQ交流群:750815713
# class base views

class Cbvdemo(View):
    context = {
        "code": 0,
        "msg": ""
    }

    def get(self, request):
        self.context["msg"] = "这是Cbvdemo get请求"
        return JsonResponse(self.context)

    def post(self, request):
        self.context["msg"] = "这是Cbvdemo post请求"
        return JsonResponse(self.context)

urls.py 配置访问路径

from django.conf.urls import url

urlpatterns = [

    url(r'^fbvdemo/$', views.fbvdemo),
    url(r'^cbvdemo/$', views.Cbvdemo.as_view()),
]

这2种方式从功能上讲都可以实现对应的功能,从代码的可读性来讲,建议多使用 CBV 模式。
另外通过 CBV 如果想要在执行get或post方法前执行其他步骤,可以重写dispatch。

login_requierd登录校验

FBV 模式如果需要加登录之后才能访问,只需在函数上加装饰器@login_required

from django.contrib.auth.decorators import login_required

# function base views

@login_required
def fbvdemo(request):
    '''function base views'''
    context = {
        "code": 0,
        "msg": ""
    }
    if request.method == "GET":
        context["msg"] = "这是fbvdemo get请求"
        return JsonResponse(context)

    if request.method == "POST":
        context["msg"] = "这是fbvdemo POST请求"
        return JsonResponse(context)

没加装饰器之前,可以直接访问

C:\Users\dell>http http://localhost:8000/fbvdemo/
HTTP/1.1 200 OK
Content-Length: 55
Content-Type: application/json
Date: Sat, 23 Nov 2019 06:26:58 GMT
Server: WSGIServer/0.2 CPython/3.6.0
Vary: Origin
X-Frame-Options: SAMEORIGIN

{
    "code": 0,
    "msg": "这是个get请求"
}

加了@login_required装饰器后,没登录的话会302重定向到登录页 /accounts/login/

C:\Users\dell>http http://localhost:8000/fbvdemo/
HTTP/1.1 302 Found
Content-Length: 0
Content-Type: text/html; charset=utf-8
Date: Sat, 23 Nov 2019 06:27:19 GMT
Location: /accounts/login/?next=/fbvdemo/
Server: WSGIServer/0.2 CPython/3.6.0
Vary: Origin, Cookie
X-Frame-Options: SAMEORIGIN
CBV 模式加 login_requierd 登录校验

method_decorator给CBV视图添加登录校验。

from django.utils.decorators import method_decorator
from django.contrib.auth.decorators import login_required
# 上海-悠悠,QQ交流群:750815713

class Cbvdemo(View):
    context = {
        "code": 0,
        "msg": ""
    }

    @method_decorator(login_required)
    def get(self, request):
        self.context["msg"] = "这是Cbvdemo get请求"
        return JsonResponse(self.context)
    
    @method_decorator(login_required)
    def post(self, request):
        self.context["msg"] = "这是Cbvdemo post请求"
        return JsonResponse(self.context)

也可以直接在class上用装饰器

from django.utils.decorators import method_decorator
from django.contrib.auth.decorators import login_required

@method_decorator(login_required, name='get')
@method_decorator(login_required, name='post')
class Cbvdemo(View):
    context = {
        "code": 0,
        "msg": ""
    }

    def get(self, request):
        self.context["msg"] = "这是Cbvdemo get请求"
        return JsonResponse(self.context)

    def post(self, request):
        self.context["msg"] = "这是Cbvdemo post请求"
        return JsonResponse(self.context)

标签:FBV,views,self,视图,django,context,msg,login
来源: https://blog.51cto.com/u_15249893/2848148