Django 自定义 error_messages={} 返回错误信息

Considerations regarding model’s​​error_messages​​​​¶​​

Error messages defined at the​​formfield​​​level or at the​​form Meta​​​level always take precedence over the error messages defined at the​​modelfield​​level.

Error messages defined on​​modelfields​​​are only used when the​​ValidationError​​​is raised during the​​model validation​​step and no corresponding error messages are defined at the form level.

#您可以通过将NON_FIELD_ERRORS键添加到ModelForm的内部Meta类的error_messages字典中来覆盖模型验证所引起的NON_FIELD_ERRORS错误消息：

You can override the error messages from​​NON_FIELD_ERRORS​​​raised by model validation by adding the​​NON_FIELD_ERRORS​​​key to the​​error_messages​​​dictionary of the​​ModelForm​​​’s inner​​Meta​​class:

from django.core.exceptions import NON_FIELD_ERRORS
from django.forms import ModelForm

class ArticleForm(ModelForm):
    class Meta:
        error_messages = {
            NON_FIELD_ERRORS: {
                'unique_together': "%(model_name)s's %(field_labels)s,
            }
        }




对于常见序列化error_message可以使用以下：

例子IntegerField

class ShopCartSerializer(serializers.Serializer):

nums = serializers.IntegerField(required=True,label='数量',min_value=1,error_messages={

"min_value":"商品数量不能小于一","required":"请选择购物数量"})

不同类型的字段有不同的error_messages 定义

查看rest framework 源码 看到最基础的field 中定义了两个error_messages

class Field(object):
_creation_counter = 0

default_error_messages = {
'required': _('This field is required.'),
'null': _('This field may not be null.')
}
不同字段中还定义了不同的error_messages IntegerField 中增加了

class IntegerField(Field):
default_error_messages = {
'invalid': _('A valid integer is required.'),
'max_value': _('Ensure this value is less than or equal to {max_value}.'),
'min_value': _('Ensure this value is greater than or equal to {min_value}.'),
'max_string_length': _('String value too large.')
}
这里面的字段我们可以自定义返回前端

CharField

class CharField(Field):
default_error_messages = {
'invalid': _('Not a valid string.'),
'blank': _('This field may not be blank.'),
'max_length': _('Ensure this field has no more than {max_length} characters.'),
'min_length': _('Ensure this field has at least {min_length} characters.')
}
例子：

code = serializers.CharField(required=True, write_only=True, max_length=6, min_length=6,
error_messages={
"blank": "请输入验证码",
"required": "请输入验证码",
"max_length": "验证码格式错误",
"min_length": "验证码格式错误"
},
help_text="验证码")

外键字段

class PrimaryKeyRelatedField(RelatedField):
default_error_messages = {
'required': _('This field is required.'),
'does_not_exist': _('Invalid pk "{pk_value}" - object does not exist.'),
'incorrect_type': _('Incorrect type. Expected pk value, received {data_type}.'),
}

当然也可以使用validator:

project_name = serializers.CharField(max_length=50, required=True,
                                     validators=[UniqueValidator(queryset=models.ProjectInformation.objects.all())]
                                     )

还可以再extra_kwargs里使用:

class Meta:
    model = models.JenkinsServices
    fields = "__all__"
    validators = [
        UniqueTogetherValidator(
            queryset=models.JenkinsServices.objects.all(),
            fields=['project_id', 'service_name']
        )
    ]
    extra_kwargs = {"service_name": {"error_messages": {"required": "Give your service_name"}}}

其次模型层也可以限制：

from django.core.validators import (MaxValueValidator, MinValueValidator,
                                    MinLengthValidator,MaxLengthValidator)

class JenkinsServices(models.Model):
    project_id = models.IntegerField(
                                     validators=[MaxValueValidator(1000), MinValueValidator(1)])
    service_name = models.CharField(max_length=100, null=False)