Django--form验证及错误处理

需求

from表单验证和ajax验证时返回的错误信息处理

速查

1、form表单提交时错误信息显示

views

error = form表单实例化对象.errors
return render(request,'前端html',{'obj':form表单实例化对象,'error':error})    #传到前端用simple_tag解析

html

{% load xx %}    <!--导入自定义sample_tag语言文件-->
<span>{% error_msg error.username %}</span>    <!--error.username当做参数传给error_msg函数，并获取返回值-->

simple_tag

@register.simple_tag
def error_msg(error_list):
    if error_list:
        return error_list[0]
    return ''

2、ajax提交时错误信息返回

views

error = obj.errors.as_json()
return HttpResponse(error)

html

$.ajax({
            success: function(arg){                //arg是返回值，必须是字符串
                var callback_dict = $.parseJSON(arg);
                $('#uname_error').text(callback_dict.username[0].message);
            }
        })

知识点

obj=表单生成文件.表单创建的类（request.POST）

request.POST：所有提交信息

obj.is_valid()：判断提交数据是否正确

obj.clean()：获取提交的所有数据

obj.errors()：获取提交的所有错误信息，有三种表示方式（as_ul、as_json、as_data）：

form表单提交用默认的，type<class django.forms.utils.ErrorDict>
ajax返回信息用as_json()，type<'str'>

错误信息里包含的字段和form里的字段一样，错误是个列表，取值obj.errors['username'][0]

html中jinja2语法取字典是不能用errors['key']的方式，得用errors.key;如果获取obj.errors['username'][0]，就得用sample_tag

详细

1、form表单提交时错误信息显示

app01/views/account.py

from app01.forms import account as AccountForm
 
def login(request):
    obj = AccountForm.LoginForm(request.POST)
    if request.method=='POST':
        if obj.is_valid():
            all_data = obj.clean()
        else:
            error = obj.errors
            return render(request,'account/login.html',{'obj':obj,'error':error})
    return render(request,'account/login.html',{'obj':obj})

为什么使用sample_tag去取值，而不取好了再传到html，因为如果字段很多的话，要分别定义每个的错误；

templates/login.html

{% load xx %}    <!--导入自定义sample_tag语言文件-->
<html lang="en">
<head></head>
<body>
    <form action="/login/" method="post">
        <p>
            {{ obj.username }}
            <span>{% error_msg error.username %}</span>    <!--error.username当做参数传给error_msg函数，并获取返回值-->
        </p>
        <p>
            {{ obj.password }}<span>{% error_msg error.password %}</span>
        </p>
        <input type="submit" value="submit" />
    </form>
</body>
</html>

app01/templatetags/xx.py

from django import template
from django.utils.safestring import mark_safe
from django.template.base import resolve_variable, Node, TemplateSyntaxError
 
register = template.Library()
 
@register.simple_tag
def error_msg(error_list):
    if error_list:
        return error_list[0]

browser

2、ajax提交时错误信息返回

ajax必须返回的是字符串，所以用as_json()格式。

先看as_json获取的信息格式

{
    "username": [
        {"message": "This field is required.", "code": "required"}
    ],
    "password": [
        {"message": "This field is required.", "code": "required"}
    ]
}

app01/views/account.py

from app01.forms import account as AccountForm
 
def login(request):
    obj = AccountForm.LoginForm(request.POST)
    if request.method=='POST':
        if obj.is_valid():
            all_data = obj.clean()
        else:
            error = obj.errors.as_json()
            return HttpResponse(error)
    return render(request,'account/login.html',{'obj':obj})

templates/login.html

<form action="/login/" method="post">
    <p>
        {{ obj.username }}
        <span id="uname_error"></span>
    </p>
    <p>
        {{ obj.password }}
        <span id="pwd_error"></span>
    </p>
{#        <input type="submit" value="submit" />#}
    <input type="button" value="AjaxSubmit" onclick="AjaxSubmit();"/>
</form>
 
<script src="{{ STATIC_URL }}js/jquery-2.1.4.min.js"></script>
<script type="text/javascript">
    function AjaxSubmit(){
        $.ajax({
            url: '/login/',
            type: 'POST',
            data: {'username':'','password':''},    //就当提交了一个空数据，制造错误
            success: function(arg){                //arg是返回值，必须是字符串
                var callback_dict = $.parseJSON(arg);
                $('#uname_error').text(callback_dict.username[0].message);
                $('#pwd_error').text(callback_dict.password[0].message);
{#                    console.log(callback_dict.username[0].message)#}
            }
        })
    }
</script>

app01/forms/account.py

from django import forms
 
class LoginForm(forms.Form):
    username = forms.CharField()
    password = forms.CharField(widget=forms.PasswordInput())

browser

来自为知笔记(Wiz)