Default selected option for LookupChoiceFilter ?

[Kagee]

I have read docs, source code, and more source code - is there no way to configure a default selected value for the LookupChoiceFilter dropdown?

Django 3.2
django-filter 23.3

I currently have a LookupChoiceFilter as follows

name = django_filters.LookupChoiceFilter(
     lookup_choices=[
        ('icontains', 'Contains'),
        ('istartswith', 'Starts with'),
        ('iexact', 'Equals'),
    ],
    # empty_label='Contains', # Only changes the label from ----- to Contains
    # empty_value='icontains', # does nothing
    # lookup_expr=('icontains', 'Contains'), # does nothing
    # lookup_expr='icontains', # does nothing
    # required=True, # just makes both fields required, user must still select from dropdown
    # label="exact",  # does nothing     
    # null_value='icontains', # Field.__init__() got an unexpected keyword argument '...'
    # default=('icontains', 'Contains'),  # Field.__init__() got an unexpected keyword argument '...'
    # default='icontains', # Field.__init__() got an unexpected keyword argument '...'
    )

[Kagee]

Alternatively, is it possible for me to supply the whole dropdown form element myself?

[carltongibson]

You should be able to pass the initial kwarg, that will get passed to the form field. https://docs.djangoproject.com/en/4.2/ref/forms/fields/#django.forms.Field.initial

[Kagee]

Neither of these three worked...

class OrderItemFilter(django_filters.FilterSet):
      name = django_filters.LookupChoiceFilter(
           lookup_choices=[
          ('icontains', 'Contains'),
          ('istartswith', 'Starts with'),
          ('iexact', 'Equals'),
      ],
      # initial=('icontains', 'Contains'),  # does nothing
      # initial='icontains',  # does nothing
      # initial='Contains',  # does nothing
     )

[Kagee]

Just for fun i also tried this, no worky

class OrderItemFilter(django_filters.FilterSet):
      name = django_filters.LookupChoiceFilter(
           lookup_choices=[
          ('icontains', '---------'), # Just created a extra optionwith label --------- and value icontains
          ('icontains', 'Contains'),
          ('istartswith', 'Starts with'),
          ('iexact', 'Equals'),
      ],
      )

[carltongibson]

See the test case here:

django-filter/tests/test_forms.py

Lines 161 to 170 in 4a618e0

	def test_filter_with_initial(self):
	class F(FilterSet):
	status = ChoiceFilter(choices=STATUS_CHOICES, initial=1)
	class Meta:
	model = User
	fields = ["status"]
	f = F().form
	self.assertEqual(f.fields["status"].initial, 1)

... but you have to pass the initial data in the format expect for the multi-value field... [..., 'icontains'] I suppose.

[Kagee]

Solution: empty_label=None,

I could get no version of inital to work.

After having read hundreds of documentation pages and source code lines for both Django and django-filters i found that this will work - there will be no empty option element, and the first tuple in lookup_choices will be the top of the list. It will not have the selected HTML attribute, but still works.

If this is how it is supposed to be done i strongly suggest it is added to the documentation, optionally the correct way.

class OrderItemFilter(django_filters.FilterSet):
      name = django_filters.LookupChoiceFilter(
           lookup_choices=(
              ('icontains', 'Contains'),
              ('istartswith', 'Starts with'),
              ('iexact', 'Equals'),
          ),
      empty_label=None,
      )

      class Meta:
          model = OrderItem