Django之Ajax

  1. ajax(特点：异步请求和局部刷新)

    版本一：利用ajax做到局部刷新页面向后端提交数据，前端接受后端返回的数据来选择跳转还是添加页面信息。
views:
    from django.shortcuts import render,HttpResponse

    # Create your views here.
    def login(request):
        if request.method=='GET':
            return render(request,'login.html')
        else:
            user = request.POST.get('username')
            pwd = request.POST.get('password')
            print(user,pwd)
            if user == 'liu' and pwd == '123':
                return HttpResponse('1')
            else:
                return HttpResponse('0')
    def home(request):
        return render(request,'home.html')

    urls:

    from app01 import views
    urlpatterns = [
        url(r'^admin/', admin.site.urls),
        url(r'^login/$',views.login,name='login'),
        url(r'^home/$',views.home,name='home'),

    login.html:

    {% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
用户名：<input type="text" id="username" >
密码：<input type="password" id="password" >
<button id="btn">提交</button>
<span></span>
</body>
<script src="{% static 'jquery.js' %}"></script>
<script>
    $('#btn').click(function () {
        var user = $('#username').val();
        var pwd = $('#password').val();
        console.log(user,pwd);
        $.ajax({
            url:'{% url "login" %}',
            type:'post',
            data:{username:user,password:pwd},
            success:function (res) {
                console.log(res,typeof res);
                if(res==='1'){
                    location.href = '/home/'
                }else{
                    $('span').text('用户名或密码错误')
                }
            }
        })
    })
</script>
</html>

    home.html:

    <!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>day,day,up</h1>
</body>
</html>

  2. csrftoken

    2.1 原理：

    详述CSRF（Cross-site request forgery），中文名称：跨站请求伪造，也被称为：one click attack/session riding，缩写为：CSRF/XSRF。攻击者通过HTTP请求江数据传送到服务器，从而盗取回话的cookie。盗取回话cookie之后，攻击者不仅可以获取用户的信息，还可以修改该cookie关联的账户信息。

    1570707900302

    所以解决csrf攻击的最直接的办法就是生成一个随机的csrftoken值，保存在用户的页面上，每次请求都带着这个值过来完成校验。

    https://blog.csdn.net/qq_42327755/article/details/80575565?tdsourcetag=s_pcqq_aiomsg

    2.2 例证：

    form表单通过csrf认证
login.html
    <form action="" method="post">
        {% csrf_token %}
        用户名：<input type="text" name="username">
        密码：<input type="password" name="password">
        <input type="submit">
    </form>

    ajax通过csrf认证（三种方式）
第一种：
    <body>
    {% csrf_token %}-----浏览器渲染加上一个隐藏的input标签
    用户名: <input type="text" id="username">
    密码: <input type="password" id ='password'>
    <button id="btn">提交</button>
    <span></span>
    </body>
    <script src="{% static 'js/jquery.js' %}"></script>
    <script>
        $('#btn').click(function () {
            var user = $('#username').val();
            var pwd = $('#password').val();
            var csrf = $('[name=csrfmiddlewaretoken]').val();---获取隐藏input标签里的value值
            $.ajax({
                url: '{% url "login" %}',
                type: 'post',
                data: {username: user, password: pwd,csrfmiddlewaretoken:csrf},---将数据添加上传
                success: function (res) {
                    if (res === '1') {
                        location.href = '/home/'
                    } else {
                        $('span').text('用户名或密码错误')
                    }
                }
            })
        })
    </script>

    第二种：
{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
{#from表单通过csrf#}
{#<form action="" method="post">#}
{#    {% csrf_token %}#}
{#    用户名：<input type="text" name="username">#}
{#    密码：<input type="password" name="password">#}
{#    <input type="submit">#}
{#</form>#}

{#{% csrf_token %}#}
用户名: <input type="text" id="username">
密码: <input type="password" id ='password'>
<button id="btn">提交</button>
<span></span>
</body>
<script src="{% static 'js/jquery.js' %}"></script>
<script>
    $('#btn').click(function () {
        var user = $('#username').val();
        var pwd = $('#password').val();
        {#var csrf = $('[name=csrfmiddlewaretoken]').val();#}
        var csrf = '{{ csrf_token }}';---{{变量}}浏览器直接将变量渲染成csrf_token值
        {#var csrf = $('')#}
        $.ajax({
            url: '{% url "login" %}',
            type: 'post',
            data: {username: user, password: pwd,csrfmiddlewaretoken:csrf},
            success: function (res) {
                if (res === '1') {
                    location.href = '/home/'
                } else {
                    $('span').text('用户名或密码错误')
                }
            }
        })
    })

</script>
</html>

    第三种：
{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
用户名: <input type="text" id="username">
密码: <input type="password" id ='password'>
<button id="btn">提交</button>
<span></span>
</body>
<script src="{% static 'js/jquery.js' %}"></script>
<script src="{%  static 'js/jquery.cookie.js'%}"></script>
<script>
    $('#btn').click(function () {
        var user = $('#username').val();
        var pwd = $('#password').val();

        $.ajax({
            url: '{% url "login" %}',
            type: 'post',
            data: {username: user, password: pwd},
            headers:{
                "X-CSRFToken":$.cookie('csrftoken'),
            },----直接对cookie操作添加键值对即可
            success: function (res) {
                if (res === '1') {
                    location.href = '/home/'
                } else {
                    $('span').text('用户名或密码错误')
                }
            }
        })
    })
</script>
</html>

    1. 上传文件

      3.1 form表单上传文件

      views:
from django.shortcuts import render,HttpResponse,redirect
from django.http import JsonResponse
def upload(request):
    if request.method=='GET':
        return render(request,'upload.html')
    else:
        print(request.POST)
        print(request.FILES)
        file_obj = request.FILES.get('file')
        print(file_obj.name)
        with open(file_obj.name,'wb') as f:
           第一种： for i in file_obj:
                f.write(i)
           第二种：for chunk in file_obj.chunks():防止/r/n
                f.write(chunk)

        return HttpResponse('ok')
        
   upload.html
   {% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="" method="post" enctype="multipart/form-data">
    {% csrf_token %}
    用户名：<input type="text" id="username">
    密码：<input type="password" id = 'password'>
    <span></span>
    头像：<input type="file" name="file">
    <input type="submit">
</form>
</body>
<script src="{% static 'js/jquery.js' %}"></script>
</html>

      3.2 ajax上传文件

      views:
from django.conf import settings
def upload(request):
    if request.method=='GET':
        return render(request,'upload.html')
    else:

        file_obj = request.FILES.get('file')
        with open(file_obj.name,'wb') as f:
            for chunk in file_obj.chunks():
                f.write(chunk)

        return HttpResponse('ok')


upload.html
{% load static %}
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    用户名：<input type="text" id="username">
    密码：<input type="password" id = 'password'>
    头像：<input type="file">
    <button id="stn">提交</button>
</body>
<script src="{% static 'js/jquery.js' %}"></script>
<script src="{% static 'js/jquery.cookie.js' %}"></script>
<script>
    $('#stn').click(function () {
        var formdata = new FormData();
        var user = $('#username').val();
        var pwd = $('#password').val();
        var file_obj = $('[type=file]')[0].files[0];
        formdata.append('user',user);
        formdata.append('pwd',pwd);
        formdata.append('file',file_obj);
        $.ajax({
            url:'{% url "upload" %}',
            type:'post',
            data:formdata,
            headers:{
                "X-CSRFToken":$.cookie('csrftoken'),
            },
            processData:false,
            contentType:false,
            success:function (res) {
                console.log(res)                      
            }                     
        })
    }) 
</script>
    
</html>

    2. jsonresponse

      from django.http import JsonResponse

        username = request.POST.get('username')
        pwd = request.POST.get('password')
        ret_data = {'status':None,'msg':None}
        print('>>>>>',request.POST)
        #<QueryDict: {'{"username":"123","password":"123"}': ['']}>
        if username == 'chao' and pwd == '123':
            ret_data['status'] = 1000  # 状态码
            ret_data['msg'] = '登录成功'
        else:
            ret_data['status'] = 1001  # 状态码
            ret_data['msg'] = '登录失败'

        # ret_data_json = json.dumps(ret_data,ensure_ascii=False)
        # return HttpResponse(ret_data_json,content_type='application/json')
        return JsonResponse(ret_data)---做了上面两句话所做的事情


       $.ajax({
            url:'{% url "jsontest" %}',
            type:'post',
            // data:{username:uname,password:pwd,csrfmiddlewaretoken:csrf},           //data:JSON.stringify({username:uname,password:pwd}),
            data:{username:uname,password:pwd},
            headers:{
                // contentType:'application/json',
                "X-CSRFToken":$.cookie('csrftoken'),
            },
            success:function (res) {
                {#console.log(res,typeof res); // statusmsg {"status": 1001, "msg": "登录失败"}#}
                {#var res = JSON.parse(res);  //-- json.loads()#}
                console.log(res,typeof res);  //直接就是反序列化之后的了
                //JSON.stringify()  -- json.dumps
                if (res.status === 1000){
                    // $('.error').text('登录成功');
                    location.href = '/home/'; // http://127.0.0.1:8000/home/
                }else{
                    $('.error').text(res.msg);
                }
            }
        })
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原文地址：https://www.cnblogs.com/-777/p/11656502.html