上一篇我们使用了 jQuery 的 get
方法来实现了 AJAX,本篇我们采用 post
方法来实现。
编写 test.html
:
<body>
<p>姓名:<input type="text" id="name" value=""></p>
<p>年龄:<span id="result"></span></p>
<button id="AJAX_get" type="button">ajax get</button>
<button id="AJAX_post" type="button">ajax post</button>
</body>
<script type="text/javascript">
// 请求服务器,返回JSON
$(document).ready(function(){
$("#AJAX_post").click(function(){
var name = $("#name").val(); // 获取输入框的值
var data = {"name": name}; // 打包成get请求发送的数据
// post 方法请求服务器
$.post(
// 请求的url
'{% url 'ajax_post' %}',
// 发送的数据
data,
// 回调函数,其中ret是返回的JSON
function(ret){
var name = ret['name'];
var age = ret['age'];
// 把查询结果输出到网页上
$("#result").text(age);
})
})
})
</script>
和 get
方法最大的不同,由于 django 中对 post
增加了 CSRF 的保护,所以其 views.py
的响应函数需要加上 @csrf_exempt
装饰器,该装饰器意味着在该方法中取消 CSRF 保护:
from django.views.decorators.csrf import csrf_exempt
# AJAX的post方法
@csrf_exempt
def ajax_post(request):
# 获取前端输入的内容
name = request.POST.get('name')
try:
student = Student.objects.get(name=name)
age = student.age
except:
age = "该姓名不存在"
data = {}
data['name'] = name
data['age'] = age
return JsonResponse(data)
其余步骤和 get
方法一摸一样。
以上方法明显是不安全的,为了使 AJAX 的 post 方法拥有 CSRF 保护,我们需要在页面加上以下这段 js 代码:
jQuery(document).ajaxSend(function(event, xhr, settings) {
function getCookie(name) {
var cookieValue = null;
if (document.cookie && document.cookie != '') {
var cookies = document.cookie.split(';');
for (var i = 0; i < cookies.length; i++) {
var cookie = jQuery.trim(cookies[i]);
// Does this cookie string begin with the name we want?
if (cookie.substring(0, name.length + 1) == (name + '=')) {
cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
break;
}
}
}
return cookieValue;
}
function sameOrigin(url) {
// url could be relative or scheme relative or absolute
var host = document.location.host; // host + port
var protocol = document.location.protocol;
var sr_origin = '//' + host;
var origin = protocol + sr_origin;
// Allow absolute or scheme relative URLs to same origin
return (url == origin || url.slice(0, origin.length + 1) == origin + '/') ||
(url == sr_origin || url.slice(0, sr_origin.length + 1) == sr_origin + '/') ||
// or any other URL that isn't scheme relative or absolute i.e relative.
!(/^(\/\/|http:|https:).*/.test(url));
}
function safeMethod(method) {
return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method));
}
if (!safeMethod(settings.type) && sameOrigin(settings.url)) {
xhr.setRequestHeader("X-CSRFToken", getCookie('csrftoken'));
}
});
view.py
中则不需使用 csrf_exempt 装饰器:
from django.views.decorators.csrf import csrf_exempt
def ajax_post(request):
# 获取前端输入的内容
name = request.POST.get('name')
try:
student = Student.objects.get(name=name)
age = student.age
except:
age = "该姓名不存在"
data = {}
data['name'] = name
data['age'] = age
return JsonResponse(data)