Django的：改变MinLengthValidator错误消息

Question

这里是如何MinLengthValidator在Django的定义：

class MinLengthValidator(BaseValidator): 
    compare = lambda self, a, b: a < b 
    clean = lambda self, x: len(x) 
    message = ungettext_lazy(
     'Ensure this value has at least %(limit_value)d character (it has %(show_value)d).', 
     'Ensure this value has at least %(limit_value)d characters (it has %(show_value)d).', 
     'limit_value') 
    code = 'min_length' 

我试着在我的代码更改错误信息是这样的：

password_min_length_validator = MinLengthValidator(8) 
password_min_length_validator.message = ungettext_lazy(
    'Ensure password has at least %(limit_value)d character (it has %(show_value)d).', 
    'Ensure password has at least %(limit_value)d characters (it has %(show_value)d).', 
    'limit_value') 

但我得到这个错误：

ugettext() takes exactly 1 argument (3 given) 

我这样做就像django.core.validators那样做。

Answer 1

看起来您使用的是早期版本的Django，因此您应该将代码基于您的Django版本的MinLengthValidator，而不是当前的实现。由于在Django 1.6中更改了ungettext_lazy方法，因此您会收到错误消息（请参见凭证#19160）。

例如，在Django 1.5.X，你会怎么做：

from django.utils.translation import ugettext_lazy as _ 

class MinLengthValidator(BaseValidator): 
    compare = lambda self, a, b: a < b 
    clean = lambda self, x: len(x) 
    message = _('Ensure this value has at least %(limit_value)d characters (it has %(show_value)d).') 
    code = 'min_length' 

password_min_length_validator = MinLengthValidator(8) 
password_min_length_validator.message = _(
    'Ensure password has at least %(limit_value)d characters (it has %(show_value)d).', 
) 

而不是设置消息你实例验证后属性的，你可以继承它：

class MyMinLengthValidator(MinLengthValidator): 
    message = _('Ensure my_field has at least %(limit_value)d characters (it has %(show_value)d).') 

my_min_length_validator = MyMinLengthValidator(8) 

另外，您可以在表单字段上使用error_messages选项：

class MyForm(forms.Form): 
    my_field = forms.CharField(validators=[MinLengthValidator(8)], 
         error_messages={'min_length': _('Ensure my_field has at least %(limit_value)d characters (it has %(show_value)d).') 
})