[Django] Development Daily _2_Day: Simple User Management System (3)

Table of contents

1. Create a template

2. Three request methods

3. Three response methods

4. Case: fake user login

( 1) Create a template

(2) csrf_token verification

( 3) POST form data acquisition and processing

(4) Handling of login failures

(5) Handling of successful login

1. Create a template

views.py

def something(request):
    #request是一个对象，封装了用户发送来的所有请求相关的数据
    #1、获取请求方式
    #2、在url上面传递值http://127.0.0.1:8000/something/?n1=123&n2=789
    print(request.GET)
    #3、在请求体中提交数据
    return HttpResponse("返回内容")

urls.py

path('something/',views.something),

access:

output:

2. Three request methods

 #1、获取请求方式
    print(request.method)
    #2、在url上面传递值http://127.0.0.1:8000/something/?n1=123&n2=789
    print(request.GET)
    #3、在请求体中提交数据
    print(request.POST)

3. Three response methods

 #4、【响应】HttpResponse("返回内容"),将字符串返回给请求者
    #return HttpResponse(123)

    #5、【响应】读取HTML的内容+渲染（替换）->字符串（网页源码），返回给用户浏览器
    #return render(request,'something.html',{"title":"requst"})

    #6、【响应】让浏览器重定向
    return redirect("https://www.baidu.com/")

Redirect processing:

4. Case: fake user login

(1) Create a template

views.py

import json

from django.shortcuts import render,HttpResponse,redirect

# Create your views here.
def index(request):
    return HttpResponse("Hello Django!")

def user_list(requets):
    return render(requets,'user_list.html')

def user_add(requets):
    return render(requets,'user_add.html')

def tpl(requets):
    name="代码骑士"
    name_list=["小明","小红","李华","康康"]
    role_dicts={"name":"小明","salary":100000,"position":"CEO"}
    data_list=[
        {"name": "小明", "salary": 100000, "position": "CEO"},
        {"name": "小红", "salary": 100000, "position": "HR"},
        {"name": "康康", "salary": 100000, "position": "CTO"}
    ]
    return render(requets,'tpl.html',{"n1":name,"n2":name_list,"n3":role_dicts,"n4":data_list})
def news(requet):
    #定义一个列表或字典存储数据
    #向网址：http://www.chinaunicom.com.cn/api/article/NewsByIndex/2/2022/09/news发送请求
    #使用第三方模块：requests
    import requests
    url = "http://www.chinaunicom.com.cn/api/article/NewsByIndex/2/2022/09/news"
    headers = {'User-Agent': 'Mozilla/4.0'}
    res = requests.get(url,headers=headers)
    data_list=res.json()
    print(data_list)
    return render(requet,'news.html',{"news_list":data_list})

def something(request):
    #request是一个对象，封装了用户发送来的所有请求相关的数据
    #1、获取请求方式
    print(request.method)
    #2、在url上面传递值http://127.0.0.1:8000/something/?n1=123&n2=789
    print(request.GET)
    #3、在请求体中提交数据
    print(request.POST)

    #4、【响应】HttpResponse("返回内容"),将字符串返回给请求者
    #return HttpResponse(123)

    #5、【响应】读取HTML的内容+渲染（替换）->字符串（网页源码），返回给用户浏览器
    #return render(request,'something.html',{"title":"requst"})

    #6、【响应】让浏览器重定向
    return redirect("https://www.baidu.com/")

def login(request):
    if request.method == "GET":
        return render(request,'login.html')
    else:
        #如果是POST请求，获取用户提交的数据
        print(request.POST)
        return HttpResponse("登录成功！")

urls.py

from django.urls import path
from app import views

urlpatterns = [
    path('index/', views.index),
    path('user/list/',views.user_list),
    path('user/add/',views.user_add),
    path('tpl/',views.tpl),
    path('news/',views.news),
    path('something/',views.something),
    #用户登录
    path('login/',views.login),
]

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>用户登录</h1>
    <form method="post" action="/login/">
        <input type="text" name="user" placeholder="用户名">
        <input type="password" name="pwd" placeholder="密码">
        <input type="submit" value="提交"/>
    </form>
</body>
</html>

access:

It seems that there is no problem, but click submit

This is because, when making a post request, Django has another layer of encryption protection mechanism, which cannot directly access the post form, and needs to make special instructions in html:

(2) csrf_token verification

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>用户登录</h1>
    <form method="post" action="/login/">
        {% csrf_token %}
        <input type="text" name="user" placeholder="用户名">
        <input type="password" name="pwd" placeholder="密码">
        <input type="submit" value="提交"/>
    </form>
</body>
</html>

Just submit it again

Django will automatically generate a hidden code for token encryption, which is used for form verification and enhances confidentiality.

Do not add this code (note that this code must be added to the form form.):

{% csrf_token %}

Django can't verify the submission form, and can't find the jump interface.

(3) POST form data acquisition and processing

def login(request):
    if request.method == "GET":
        return render(request,'login.html')
    else:
        #如果是POST请求，获取用户提交的数据
        print(request.POST)
        username=request.POST.get("user")
        password = request.POST.get("pwd")
        if username == 'root' and password == '123456':
            return HttpResponse("登录成功！")
        else:
            return HttpResponse("登录失败！")

(4) Handling of login failures

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <h1>用户登录</h1>
    <form method="post" action="/login/">
        {% csrf_token %}
        <input type="text" name="user" placeholder="用户名">
        <input type="password" name="pwd" placeholder="密码">
        <input type="submit" value="提交"/>
        <span style="color: red">{
   
   { error_msg }}</span>
    </form>
</body>
</html>

access:

(5) Handling of successful login

def login(request):
    if request.method == "GET":
        return render(request,'login.html')
    #如果是POST请求，获取用户提交的数据
    print(request.POST)
    username=request.POST.get("user")
    password = request.POST.get("pwd")
    if username == 'root' and password == '123456':
        #return HttpResponse("登录成功！")
        return redirect("https://blog.csdn.net/qq_51701007?spm=1000.2115.3001.5343")
    #return HttpResponse("登录失败！")
    return render(request,'login.html',{"error_msg":"用户名或密码错误！"})

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