[oldboy-django][2深入django]form表单clean_xx, clean完成数据验证+ form错误信息

form后台生成form里面的Input标签，以及设置Input的属性

# 需求 后台生成form里面的input标签，并设置input标签的属性，
    class RegisterForm(Form):
        email = fields.EmailField()
        password = fields.CharField()
        password2 = fields.CharField()
        code = fields.CharField()
        avatar = fields.FileField(widget=widgets.FileInput(attrs={'id': 'inputAvatar'}))

    def register(request):
        if request.method == 'GET':
            obj = RegisterForm()
            return render(request, 'register.html', {'obj': obj})
    
     <form method="POST" action="/register/" enctype="multipart/form-data">
        {% csrf_token %}
        {{ obj.avatar }}
        {{ obj.usernam }}
     </form>

向在form里面获取session值，即传递request参数

# form标签向获取request里面的值--重写__init__函数
    def __init__(self, request, *args, **kwargs):
        self.request = request
        super(RegisterForm, self).__init__(*args, **kwargs)

form验证某个字段 self.clean_字段名

# form标签验证某个字段
    def clean_code(self):
    input_code = self.cleaned_data.get('code')
    session_code = self.request.session.get('code')  # 请查看check_code函数
    if input_code != session_code:
        raise ValidationError('验证码错误')
    else:
        return input_code
    # self.errors = {'code': ['验证码错误'], 'xx':[错误1，错误2]}

form验证多个字段 self.clean

# form标签联合数据验证
    def clean(self):
    """
    此时，已经拿到所有的input值,对两次输入密码进行验证
    """
    p1 = self.cleaned_data.get('password1')
    p2 = self.cleaned_data.get('password2')
    if p1 != p2:
        raise ValidationError('两次输入密码不一致') # 默认放到self.errors['__all__']里面
    else:
        return self.cleaned_data
        # return None
    """
    self.errors = {'__all__': ['两次输入密码不一致'], 'xx':[错误1，错误2]}
    NON_FIELD_ERRORS = '__all__'   前台获取需要用到
    此时前端获取该错误; obj.non_field_errors
    """

form验证多个字段 self.clean 指明错误信息的Key,方便前端使用

# 对整体错误的其他设置
    def clean(self):

        if p1 != p2:
            self.add_error('password2', '两次输入密码不一致')
            # 此时不用抛出异常了，因为抛出异常
            # 抛出异常也是执行self.add_error
            return None
        else:
            return self.cleaned_data

    此时在前端显示该错误： obj.errors.password2

form 的错误信息self.errors

# form标签数据验证错误信息
    self.errors = {'username':[错误1， 错误2]， 'password': [错误1， 错误2]}
    def clean_xx(self) 如果遇到错，放到self.errors['xx']里面
    def clean(self) 如果遇到错，放到self.errors['__all__']里面

    但是如果要前端获取self.errors['__all__']错误，obj.errors.__all__是拿不到的
    而是obj.non_field_errors, 不是self.errors.non_fields_errors

注册form

# 完整的forms.py
    # -*- coding: utf-8 -*-
    from django.forms import Form, fields, widgets
    from django.core.exceptions import ValidationError


    class RegisterForm(Form):
        username = fields.CharField(widget=widgets.TextInput(
            attrs={'class': "form-control"}
        ))
        password = fields.CharField(widget=widgets.PasswordInput(
            attrs={'class': "form-control"}
        ))
        password2 = fields.CharField(widget=widgets.PasswordInput(
            attrs={'class': "form-control"}
        ))
        code = fields.CharField(widget=widgets.TextInput(
            attrs={'class': "form-control"}
        ))
        avatar = fields.FileField(widget=widgets.FileInput(attrs={'id': 'inputAvatar'}))

        def __init__(self, request, *args, **kwargs):
            self.request = request
            super(RegisterForm, self).__init__(*args, **kwargs)

        def clean_code(self):
            input_code = self.cleaned_data.get('code').upper()
            session_code = self.request.session.get('code').upper()  # 请查看check_code函数
            if input_code != session_code:
                raise ValidationError('验证码错误')
            else:
                return input_code
            # self.errors = {'code': ['验证码错误'], 'xx':[错误1，错误2]}

        def clean(self):
            """
            此时，已经拿到所有的input值,对两次输入密码进行验证
            """
            p1 = self.cleaned_data.get('password')
            p2 = self.cleaned_data.get('password2')
            if p1 != p2:
                self.add_error('password2', '两次输入密码不一致') # 此时不用抛出异常了，因为抛出异常
                # 抛出异常也是执行self.add_error
                return None
                # raise ValidationError('两次输入密码不一致')
                #  默认放到self.errors['__all__']里面
                #  执行的是self.add_error('__all__', '两次输入密码不一致')
            else:
                return self.cleaned_data

    """
    self.errors = {'__all__': ['两次输入密码不一致'], 'xx':[错误1，错误2]}
    NON_FIELD_ERRORS = '__all__'   前台获取需要用到
    """