How to change datetime format in Django-filter form?

Question

I'm creating a filter which contains datetime range choice. I would like user to be able to input date in this format: 24.08.2017 17:09

From docs, it is possible to specify a widget (from django.forms) and widget has attribute input_formats.

So this would be a solution:

datetime_range = django_filters.DateTimeFromToRangeFilter(method='datetime',
                 label=u'Čas od do',widget=forms.widgets.DateTimeInput(format="%D.%m.%Y %H:%M:%S")

The problem is that it uses DateTimeFromToRangeFilter which uses two DateTimeInput fields. So if I specify the widget, it renders one DateTimeInput instead of two inputs.

So the question is, how to specify the format (without changing widget)?

I'm trying to specify input_formats inside __init__(...) but it raises:

Exception Value: can't set attribute

def __init__(self,*args,**kwargs):
    self.base_filters['datetime_range'].field = (forms.DateTimeField(input_formats=["%D.%m.%Y %H:%M"]),forms.DateTimeField(input_formats=["%D.%m.%Y %H:%M"]))

Answer 1

An easy solution would be to simply modify the DATETIME_INPUT_FORMATS setting.

Alternatively, you could create a custom field, based on the existing DateTimeRangeField.

class CustomDateTimeRangeField(django_filters.RangeField):

    def __init__(self, *args, **kwargs):
        fields = (
            forms.DateTimeField(input_formats=["%D.%m.%Y %H:%M"]),
            forms.DateTimeField(input_formats=["%D.%m.%Y %H:%M"]),
        )
        super(CustomDateTimeRangeField, self).__init__(fields, *args, **kwargs)

From here, you can either create a separate class, or override the field_class for all DateTimeFromToRangeFilters.

class CustomDateTimeFromToRangeFilter(django_filters.RangeFilter):
    field_class = CustomDateTimeRangeField

# or 

django_filters.DateTimeFromToRangeFilter.fields_class = CustomDateTimeRangeField