[py][mx]django form验证-给db减压

django form认证-解压db压力

一般系统都需要前后端都验证
前端验证容器逃逸破解,如通过js console口去发

试想如果后端只有db验证,那么前端无论发什么后端都查询一次db,对db压力太大, 所以后端先通过form验证,对其长度等验证通过后才db验证.

新建forms.py

forms.py里的字段要和前端的login表单字段name对应上

users/forms.py

from django import forms

class LoginForm(forms.Form):

    username = forms.CharField(required=True)

    password = forms.CharField(required=True)

users/viewspy

from django.contrib.auth import authenticate, login

from django.contrib.auth.backends import ModelBackend

from django.db.models import Q

from django.shortcuts import render

from django.views.generic import View

# Create your views here.

from users.forms import LoginForm

from users.models import UserProfile

class UserView(View):  # 新的login view. 继承了View类,它里面实现get post等方法, 使用类模式写免去了函数模式的判断

    def get(self, request):

        return render(request, "login.html", {})

    def post(self, request):

        login_form = LoginForm(request.POST)  # 传递进来的字段先进行表单验证,如果规则通过在进入查库逻辑

        if login_form.is_valid():

            user_name = request.POST.get("username", "")  # 字典取值,如果无,赋值为空

            pass_word = request.POST.get("password", "")

            user = authenticate(username=user_name, password=pass_word)

            if user is not None:  # 用户名密码验证成功

                login(request, user)  # django执行用户登录

                return render(request, "index.html")

            else:

                return render(request, "login.html", {'msg': "用户名或密码错误"})

        else:

            return render(request, "login.html", {'msg': "用户名或密码不符合规则"})

此时如果前端什么都不输入提交

debug模式看到

返回form报错到前端

users/views.py

class UserView(View):  # 新的login view. 继承了View类,它里面实现get post等方法, 使用类模式写免去了函数模式的判断

    def get(self, request):

        return render(request, "login.html", {})

    def post(self, request):

        login_form = LoginForm(request.POST)  # 传递进来的字段先进行表单验证,如果规则通过在进入查库逻辑

        if login_form.is_valid():

            user_name = request.POST.get("username", "")  # 字典取值,如果无,赋值为空

            pass_word = request.POST.get("password", "")

            user = authenticate(username=user_name, password=pass_word)

            if user is not None:  # 用户名密码验证成功

                login(request, user)  # django执行用户登录

                return render(request, "index.html")

            else:

                return render(request, "login.html", {'msg': "用户名或密码错误"})

        else:

            return render(request, "login.html", {'msg': "用户名或密码不符合规则", "login_form": login_form}) # 将django的form验证失败内置信息发给前端展示用

templates/login.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>login</title>

</head>

<body>

<div>

    <form action="/login/" method="post">

        <p><input type="text" name="username" placeholder="username"></p>

        <p><input type="text" name="password" placeholder="password"></p>

        <p><input type="submit"></p>

        {% csrf_token %}

    </form>

    {% if login_form.errors.username %}

        {% for key,value in login_form.errors.items %}

            {{ key }}: {{ value }}

        {% endfor %}

    {% endif %}

    {{ msg }}

</div>

</body>

</html>

也可以单独把erros提取出来返回给前端, 如error_msg = user_input_obj.errors

form有2个作用: 1, 验证 2,生成html(另一种写法了)

        if user_input_obj.is_valid():#form验证通过

        ...

        else:

            error_msg = user_input_obj.errors

            return render(request, "user_list.html", {'obj': user_input_obj, 'errors': error_msg})#错误信息返回

前端页面:

    <form action="/user_list/" method="post">

        <p>用户类型: {{ obj.user_type }} <span>{{ errors.user_type }}</span></p>

         ....

        {% csrf_token %}

    </form>

巴特西

[py][mx]django form验证-给db减压

django form认证-解压db压力

新建forms.py

返回form报错到前端

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