MinValueValidator and Date Localization in Django

Understanding the Issue

Based on the information provided, you're encountering a localization issue with MinValueValidator when used with date fields. While Django correctly translates the error message text into German, it doesn't localize the date format in the error message, keeping it in the YYYY-MM-DD format instead of the expected German format (DD.MM.YYYY).

Addressing Your Questions

a) Are you doing something wrong?

No, you're not doing anything wrong. The current implementation of MinValueValidator doesn't automatically localize the date format in error messages. The validator simply converts the limit value to a string without applying locale-specific formatting.

b) Could this be a feature request?

Yes, this could definitely be considered a valid feature request for Django. Currently, Django has the localize parameter for form fields as shown in the documentation:

PYTHONCopied
class CashRegisterForm(forms.Form):
    product = forms.CharField()
    revenue = forms.DecimalField(max_digits=4, decimal_places=2, localize=True)

However, there's no equivalent parameter for validators to localize their error message values. Adding such functionality would enhance the internationalization capabilities of Django, especially for applications serving users from different regions.

Workaround Solutions

Until this feature is potentially implemented, you have a few options:

1. Custom Validator: Create a custom validator that extends MinValueValidator and overrides the error message with a localized date format.

2. Custom Error Message: Provide a custom error message to the validator that includes the date in the format you want:

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from django.utils.formats import date_format
from django.utils.translation import gettext_lazy as _

min_date = date(2020, 1, 1)
formatted_date = date_format(min_date, format='SHORT_DATE_FORMAT', use_l10n=True)
custom_message = _("This value must be greater than or equal to %(limit_value)s.")

validators=[MinValueValidator(
    min_date, 
    message=custom_message % {'limit_value': formatted_date}
)]

3. Custom Clean Method: Handle the validation in the model's clean method where you have more control over the error message formatting.

Your suggestion to enhance Django's localization capabilities for validators is valid and would be a useful addition to the framework's internationalization features.