id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30578	SelectDateWidget doesn't use DATE formats properly when settings.USE_L10N=False.	fensta	Shubham Bhagat	"I think I found a bug in Django related to L10N.  I'm using a SelectDateWidget in my ModelForm and want it displayed in the order <day, month, year> at the frontend. Therefore, I set 
{{{
#!div style=""font-size: 80%""
  {{{#!python
  USE_L10N=False
  }}}
}}} 
in settings.py so that my custom order specified in DATE_FORMAT takes precedence. In my case, I defined it in settings.py as

{{{
#!div style=""font-size: 80%""
  {{{#!python
  DATE_FORMAT=""d M Y""
  }}}
}}}  

Moreover, I also set

{{{
#!div style=""font-size: 80%""
  {{{#!python
DATE_INPUT_FORMATS = [
    ""%d.%m.%Y"", 
]
 }}}
}}}

However, validating any dates on the server yielded invalid dates and my custom clean method for my field wasn't called. When looking at the source code for SelectDateWidget, I found value_from_datadict():

{{{
#!div style=""font-size: 80%""
  {{{#!python
def value_from_datadict(self, data, files, name):
        y = data.get(self.year_field % name)
        m = data.get(self.month_field % name)
        d = data.get(self.day_field % name)
        if y == m == d == '':
            return None
        if y is not None and m is not None and d is not None:
           if settings.USE_L10N:  ###### <-- This is the line
                input_format = get_format('DATE_INPUT_FORMATS')[0]
                try:
                    date_value = datetime.date(int(y), int(m), int(d))
                except ValueError:
                    pass
                else:
                    date_value = datetime_safe.new_date(date_value)
                    return date_value.strftime(input_format)
            # Return pseudo-ISO dates with zeros for any unselected values,
            # e.g. '2017-0-23'.
            return '%s-%s-%s' % (y or 0, m or 0, d or 0)
        return data.get(name)
  }}}
}}}  

Shouldn't the highlighted if condition be instead?

{{{
#!div style=""font-size: 80%""
  {{{#!python
if not settings.USE_L10N:
  }}}
}}}

As far as I understand the code, without the added negation above the default date format (""year-month-day"") will be used all the time. But since I explicitly disabled L10N in the settings, I was expecting that DATE_INPUT_FORMATS will be used instead of the default format. Of course, I could be wrong as I just started with Django, so apologies in advance if I misunderstood something and the code is correct as it is right now. 

Thanks in advance,
Stefan
"	Bug	closed	Forms	dev	Normal	fixed	Locale, SelectDateWidget		Accepted	1	0	0	0	0	0