pythonWeb～柒～Django之后台管理系统及其他功能完善

后台管理系统

1. 管理员操作

2. 用户登录

http无状态短连接：

什么是cookie和session？

http://127.0.0.1:8000/admin/list/
https://127.0.0.1:8000/admin/list/

2.1 登录

登录成功后：

• cookie，随机字符串
• session，用户信息

在其他需要登录才能访问的页面中，都需要加入：

def index(request):
    info = request.session.get("info")
    if not info:
        return redirect('/login/')
    
    ...

目标：在18个视图函数前面统一加入判断。

info = request.session.get("info")
if not info:
    return redirect('/login/')

2.2 中间件的体验

• 定义中间件

  from django.utils.deprecation import MiddlewareMixin
  from django.shortcuts import HttpResponse
  
  class M1(MiddlewareMixin):
      """ 中间件1 """
  
      def process_request(self, request):
  
          # 如果方法中没有返回值（返回None），继续向后走
          # 如果有返回值 HttpResponse、render 、redirect
          print("M1.process_request")
          return HttpResponse("无权访问")
  
      def process_response(self, request, response):
          print("M1.process_response")
          return response
  
  
  class M2(MiddlewareMixin):
      """ 中间件2 """
  
      def process_request(self, request):
          print("M2.process_request")
  
      def process_response(self, request, response):
          print("M2.process_response")
          return response
  

• 应用中间件 setings.py

  MIDDLEWARE = [
      'django.middleware.security.SecurityMiddleware',
      'django.contrib.sessions.middleware.SessionMiddleware',
      'django.middleware.common.CommonMiddleware',
      'django.middleware.csrf.CsrfViewMiddleware',
      'django.contrib.auth.middleware.AuthenticationMiddleware',
      'django.contrib.messages.middleware.MessageMiddleware',
      'django.middleware.clickjacking.XFrameOptionsMiddleware',
      'app01.middleware.auth.M1',
      'app01.middleware.auth.M2',
  ]
  

• 在中间件的process_request方法

  # 如果方法中没有返回值（返回None），继续向后走
  # 如果有返回值 HttpResponse、render 、redirect，则不再继续向后执行。
  

2.3 中间件实现登录校验

• 编写中间件

  from django.utils.deprecation import MiddlewareMixin
  from django.shortcuts import HttpResponse, redirect
  
  
  class AuthMiddleware(MiddlewareMixin):
  
      def process_request(self, request):
          # 0.排除那些不需要登录就能访问的页面
          #   request.path_info 获取当前用户请求的URL /login/
          if request.path_info == "/login/":
              return
  
          # 1.读取当前访问的用户的session信息，如果能读到，说明已登陆过，就可以继续向后走。
          info_dict = request.session.get("info")
          print(info_dict)
          if info_dict:
              return
  
          # 2.没有登录过，重新回到登录页面
          return redirect('/login/')
  

• 应用中间件

  MIDDLEWARE = [
      'django.middleware.security.SecurityMiddleware',
      'django.contrib.sessions.middleware.SessionMiddleware',
      'django.middleware.common.CommonMiddleware',
      'django.middleware.csrf.CsrfViewMiddleware',
      'django.contrib.auth.middleware.AuthenticationMiddleware',
      'django.contrib.messages.middleware.MessageMiddleware',
      'django.middleware.clickjacking.XFrameOptionsMiddleware',
      'app01.middleware.auth.AuthMiddleware',
  ]
  

2.4 注销

def logout(request):
    """ 注销 """

    request.session.clear()

    return redirect('/login/')

2.5 菜单栏显示当前用户

3.图片验证码

3.1 生成图片

pip install pillow

import random
from PIL import Image, ImageDraw, ImageFont, ImageFilter


def check_code(width=120, height=30, char_length=5, font_file='Monaco.ttf', font_size=28):
    code = []
    img = Image.new(mode='RGB', size=(width, height), color=(255, 255, 255))
    draw = ImageDraw.Draw(img, mode='RGB')

    def rndChar():
        """
        生成随机字母
        :return:
        """
        return chr(random.randint(65, 90))

    def rndColor():
        """
        生成随机颜色
        :return:
        """
        return (random.randint(0, 255), random.randint(10, 255), random.randint(64, 255))

    # 写文字
    font = ImageFont.truetype(font_file, font_size)
    for i in range(char_length):
        char = rndChar()
        code.append(char)
        h = random.randint(0, 4)
        draw.text([i * width / char_length, h], char, font=font, fill=rndColor())

    # 写干扰点
    for i in range(40):
        draw.point([random.randint(0, width), random.randint(0, height)], fill=rndColor