python Django框架实现自定义表单提交

时间:2022-09-12 18:57:52

除了使用Django内置表单,有时往往我们需要自定义表单。对于自定义表单Post方式提交往往会带来由CSRF(跨站请求伪造)产生的错误"CSRF verification failed. Request aborted."

本篇文章主要针对"表单提交"和"Ajax提交"两种方式来解决CSRF带来的错误

一、表单提交
Template:

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>计算数字和</title>
</head>
<body>
  <form method="post" action="{%url 'Calculate' %}">
    {% csrf_token %}
    <label for="A"><input id="A" name="ValueA" type="text"></label>
    <label for="B"><input id="B" name="ValueB" type="text"></label>
    <input type="submit" value="开始计算">
  </form>
</body>
</html>

Views.py:

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def Calculate(request):
  if request.POST:
    a=request.POST["ValueA"]
    b=request.POST["ValueB"]
    c=str(int(a)+int(b))
    return render_to_response('Result.html',{'result':c})
  else:
    return render_to_response('Calculation.html',context_instance=RequestContext(request))

需要注意:

(1)在<form>标签内添加{% csrf_token %},这样在表单提交的过程中,会产生"csrfmiddlewaretoken"标识去防止CSRF

(2)在Get请求页面时,需要添加context_instance=RequestContext(request) ,它和{% csrf_token %}配合使用,缺少一个都会出现上述错误,RequestContext 需要在 django.shortcuts 导入

(3)只有当表单以Post方式提交时,才需要验证CSRF,Get方式是不需要的

二、Ajax提交
同比与表单提交,Ajax提交需要进行额外的操作,Ajax提交时需要自己提供"csrfmiddlewaretoken"标识参数。我们除了需要引入JQuery外还需要引入一段JS代码

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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'));
  }
});

Template:

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Ajax 提交</title>
  <script type="text/javascript" src="/static/jquery.js"></script>
  <script type="text/javascript">
    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'));
  }
});
  </script>
  <script type="text/javascript">
    $(function(){
       $.ajaxSetup({
          data:{csrfmiddlewaretoken: '{{ csrf_token }}'}
        });
        $("#Comment").click(function(){
          $.post('{% url 'AjaxRequest' %}',{"a":$("#A").val(),"b":$("#B").val()},function(data){
            $("#result").html(data);
          });
        });
    });
  </script>
</head>
<body>
  <label for="A"><input id="A" name="ValueA" type="text"></label>
  <label for="B"><input id="B" name="ValueB" type="text"></label>
  <input type="button" id="Comment" value="开始计算">
  <h1>计算的结果为:<span id="result"></span></h1>
</body>
</html>

View.py:

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def AjaxRequest(request):
  if request.POST:
    a =request.POST["a"]
    b=request.POST["b"]
    c=int(a)+int(b)
    return JsonResponse(c,safe=False)
  else:
    return render_to_response('AjaxDemo.html',context_instance=RequestContext(request))

需要注意:

(1)在使用引入的JS代码后,需要添加如下代码,这样JS就可以自动帮我们生成"csrfmiddlewaretoken"标识,接下来你就可以使用$.post()了

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$.ajaxSetup({
          data:{csrfmiddlewaretoken: '{{ csrf_token }}'}
        });

(2)context_instance=RequestContext(request) 并不是必须的

(3)Get请求不需要以上操作,直接使用$.get()即可
注:本文使用的Django1.8.3版本进行测试。

以上就是本文的全部内容,希望对大家的学习有所帮助。