from django.shortcuts import render,HttpResponse
from django import forms
from django.core.exceptions import ValidationError     #校验错误


class UserInfo(forms.Form):

    username = forms.CharField(
        label=‘用户名‘,
        required=True,
    )

    password = forms.CharField(
        label=‘密码‘,
        widget=forms.widgets.PasswordInput(render_value=True)
    )

    def clean_username(self):    #此处自定义一个校验规则的函数：用户名不能含有admin
        value = self.cleaned_data.get("username")   #获取输入的username的值
        if "admin" in value:        #如果包含了admin
            raise ValidationError("用户名不能含有敏感信息")   #则返回错误信息


def test(request):
    if request.method == ‘GET‘:
        u_obj = UserInfo()
        return render(request, ‘test.html‘, {‘u_obj‘: u_obj})
    else:
        u_obj = UserInfo(request.POST)
        if u_obj.is_valid():
            print(u_obj.cleaned_data)
            return HttpResponse(‘检验通过‘)
        else:
            print(u_obj.errors)
            return render(request, ‘test.html‘, {‘u_obj‘: u_obj})

from django.shortcuts import render,HttpResponse
from django import forms
from django.core.exceptions import ValidationError     #校验错误

#自定义一个校验的函数，如果长度大于6，则抛出错误信息
def max_num(n):
    if len(n) > 6:
        raise ValidationError(‘太长了‘)


class UserInfo(forms.Form):

    username = forms.CharField(
        label=‘用户名‘,
        required=True,

        #validators：自定义校验
        validators=[max_num]    #在此处使用自定义的函数，检验时，会自动将输入的值作为参数传入函数中，并进行校验和返回错误信息
    )


    password = forms.CharField(
        label=‘密码‘,
        widget=forms.widgets.PasswordInput(render_value=True)
    )



def test(request):
    if request.method == ‘GET‘:
        u_obj = UserInfo()
        return render(request, ‘test.html‘, {‘u_obj‘: u_obj})
    else:
        u_obj = UserInfo(request.POST)
        if u_obj.is_valid():
            print(u_obj.cleaned_data)
            return HttpResponse(‘检验通过‘)
        else:
            print(u_obj.errors)
            return render(request, ‘test.html‘, {‘u_obj‘: u_obj})