Django初体验（一）:自定义表单提交

时间：2024-01-11 09:30:14

注：本人使用的Django1.8.3版本进行测试

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."

本篇博客只要针对"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：

<!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:

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

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：

<!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：

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

 $.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

总结：本人学习Django的时间不长，写博客的目的只要是为了自己做知识记录和对知识的分享，如果哪里写的不好，还请广大博友指点，多多包涵。

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