【django学习-25】登录及使用中间件进行登录校验

  • 1.登录功能实现
    • 1.1:管理员表
from django.db import models

class Admin(models.Model):
    """ 管理员 """
    username = models.CharField(verbose_name="用户名", max_length=32)
    password = models.CharField(verbose_name="密码", max_length=64)

    def __str__(self):
        return self.username
  • 1.2:前端登录界面
{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="{% static 'plugins/bootstrap-3.4.1/css/bootstrap.min.css' %}">
    <style>
        .account {
            width: 400px;
            border: 1px solid #dddddd;
            border-radius: 5px;
            box-shadow: 5px 5px 20px #aaa;

            margin-left: auto;
            margin-right: auto;
            margin-top: 100px;
            padding: 20px 40px;
        }

        .account h2 {
            margin-top: 10px;
            text-align: center;
        }
    </style>
</head>
<body>
<div class="account">
    <h2>用户登录</h2>
    <form method="post" novalidate>
        {% csrf_token %}
        <div class="form-group">
            <label>用户名</label>
            {{ form.username }}
            <span style="color: red;">{{ form.username.errors.0 }}</span>
        </div>
        <div class="form-group">
            <label>密码</label>
            {{ form.password }}
            <span style="color: red;">{{ form.password.errors.0 }}</span>
        </div>
        <div class="form-group">
            <label for="id_code">图片验证码</label>
            <div class="row">
                <div class="col-xs-7">
                    {{ form.code }}
                    <span style="color: red;">{{ form.code.errors.0 }}</span>
                </div>
                <div class="col-xs-5">
                    <img id="image_code" src="/image/code/" style="width: 125px;">
                </div>
            </div>
        </div>
        <input type="submit" value="登 录" class="btn btn-primary">
    </form>
</div>

</body>
</html>
  • 1.3:如果用户名、密码正确,登录成功,写入cookie到浏览器,session到后台
from django.shortcuts import render, redirect,HttpResponse
from app01 import models
from app01.utils.bootstrap import BootStrapForm
from django import forms
from io import BytesIO
from app01.utils.encrypt import md5
from app01.utils.code import check_code

class LoginForm(BootStrapForm):
    username = forms.CharField(
        label="用户名",
        widget=forms.TextInput,
        required=True
    )
    password = forms.CharField(
        label="密码",
        widget=forms.PasswordInput(render_value=True),  # 错误提示的时候,内容不清空
        required=True      # 必填,默认为True
    )

    code = forms.CharField(
        label="验证码",
        widget=forms.TextInput,
        required=True
    )

    def clean_password(self):
        pwd = self.cleaned_data.get("password")
        return md5(pwd)

def login(request):
    if request.method == "GET":
        form = LoginForm()
        return render(request,"login.html",{"form":form})
    form = LoginForm(data = request.POST)
    if form.is_valid():
        # print(form.cleaned_data)  # {'username': 'xwl', 'password': '1cd19cf980df7815e8303ab92ff66296'}
        # print(form.cleaned_data)  # {'username': 'xwl', 'password': '1cd19cf980df7815e8303ab92ff66296',"code":xxx}

        # 去数据库校验用户名和密码是否正确,获取用户对象、None
        # admin_object = models.Admin.objects.filter(username=xxx, password=xxx).first()
        admin_object = models.Admin.objects.filter(**form.cleaned_data).first()
        if not admin_object:
            form.add_error("password", "用户名或密码错误")   # 主动在username字段显示错误信息
            # form.add_error("username", "用户名或密码错误")
            return render(request, 'login.html', {'form': form})

        # 用户名和密码正确
        # 网站生成随机字符串,写入浏览器的cookie中,再写入到session中
        request.session["info"] = {'id': admin_object.id, 'name': admin_object.username}
        # sesion可以保存7天
        request.session.set_expiry(60 * 60 * 24 * 7)
        return redirect('/admin/list/')

    return render(request,"login.html",{"form":form})
  • 2.网站的某些界面,必须要登录才能访问,未登录跳转到登录界面,我们可以在每个视图函数中判断,但是这个太麻烦了。Django为我们提供了一个轻量级的组件,中间件实现起来就很方便了。
    • 2.1:中间件介绍
      • 2.1.1:什么是中间件?
        • 是介于request与response处理之间的一道处理过程,相对比较轻量级,并且在全局上改变django的输入与输出。因为改变的是全局,所以需要谨慎实用,用不好会影响到性能
      • 2.1.2:中间件可以定义五个方法,分别是:(主要的是process_request和process_response),在自己定义中间件时,必须继承MiddlewareMixin
process_request(self,request)
process_view(self, request, callback, callback_args, callback_kwargs)
process_template_response(self,request,response)
process_exception(self, request, exception)
process_response(self, request, response)
- 2.1.3:中间件流程
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。

  • 2.2:使用中间件
    • 2.2.1: 定义中间件
from django.utils.deprecation import MiddlewareMixin
from django.shortcuts import render,redirect,HttpResponse

class AuthMiddleWare(MiddlewareMixin):
    def process_request(self,request):
        #  排除不需要登录运行访问的界面
        if request.path_info in ['/login/','/image/code/']:
            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")
        # 如果登录过,继续往后走
        if info_dict:
            return

        # 没登录过,返回登录界面
        return redirect('/login/')

- 2.2.2:配置中间件,setting.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.AuthMiddleWare',
]
  • 3.如上所示,我们就实现了登录功能及登录验证
posted @ 2024-05-15 20:07  Tony_xiao  阅读(154)  评论(0编辑  收藏  举报