django_filters issue with gte, lte

January 5, 2022

I am trying to filter by DateField using django_filters lib. Following the doc I encounter an issue with the "gte" and "lte" lookup_expressions (I tried both). The problem is that it only return results if the date I input in my datepicker is the exact date, which I would suspect would be the expected "iexact" or "exact" lookup_expression results. This is my simplified code, note that I have tried using only one date (removing end_date in both model and filter.py) and the result was the same so I don’t believe this is a range issue

Model 

class Replacement(models.Model):
    start_date = models.DateField(
        null=True, blank=True)
    end_date = models.DateField(
        null=True, blank=True)

filter.py 

#not sure if this DateInput is related to the issue, just a way to attach "date" type so as to get a datepicker on template

class DateInput(forms.DateInput):
    input_type = 'date'


class ReplacementFilter(django_filters.FilterSet):

    start_date = DateFilter(field_name="start_date", lookup_expr='gte')
    end_date = DateFilter(field_name="end_date", lookup_expr='gte')

    class Meta:
        model = Replacement
        fields = ['start_date', 'end_date']

    start_date = django_filters.DateFilter(
        widget=DateInput(attrs={'type': 'date'}))
    end_date = django_filters.DateFilter(
        widget=DateInput(attrs={'type': 'date'}))

 Views

def replacement_list_page(request):
 
    replacements = Replacement.objects.all()
    replacement_filter = ReplacementFilter(request.GET, queryset=replacements)
    print(replacement_filter)
    return render(request, "replacements/replacementlist.html", {"replacement": replacements, 
      'filter': replacement_filter})

Thanks

>Solution :

You defined start_date and end_date twice, once with the lookup_expr and once with the widget, as a result, the last defined DateFilters will be used, and thus ommitting the earlier defined start_date and end_date.

You thus should define the FilterSet with:

class ReplacementFilter(django_filters.FilterSet):
    start_date = DateFilter(
        field_name='start_date',
        lookup_expr='gte',
        widget=DateInput(attrs={'type': 'date'})  # 🖘 specify widget
    )
    end_date = DateFilter(
        field_name='end_date',
        lookup_expr='gte',
        widget=DateInput(attrs={'type': 'date'})  # 🖘 specify widget
    )

    class Meta:
        model = Replacement
        fields = ['start_date', 'end_date']

    # no new definitions of start_date and end_date