Remove unused filters

unicorn/utilities/filters.py

@@ -1,8 +1,4 @@
-import itertools
-
 import django_filters
-from django import forms
-from django.utils.encoding import force_str
 
 #
 # Filters
@@ -15,53 +11,3 @@ class NumericInFilter(django_filters.BaseInFilter, django_filters.NumberFilter):
     """
 
     pass
-
-
-class NullableCharFieldFilter(django_filters.CharFilter):
-    """
-    Allow matching on null field values by passing a special string used to signify NULL.
-    """
-
-    null_value = "NULL"
-
-    def filter(self, qs, value):
-        if value != self.null_value:
-            return super(NullableCharFieldFilter, self).filter(qs, value)
-        qs = self.get_method(qs)(**{"{}__isnull".format(self.name): True})
-        return qs.distinct() if self.distinct else qs
-
-
-class NullableModelMultipleChoiceField(forms.ModelMultipleChoiceField):
-    """
-    This field operates like a normal ModelMultipleChoiceField except that it allows for one additional choice which is
-    used to represent a value of Null. This is accomplished by creating a new iterator which first yields the null
-    choice before entering the queryset iterator, and by ignoring the null choice during cleaning. The effect is similar
-    to defining a MultipleChoiceField with:
-        choices = [(0, 'None')] + [(x.id, x) for x in Foo.objects.all()]
-    However, the above approach forces immediate evaluation of the queryset, which can cause issues when calculating
-    database migrations.
-    """
-
-    iterator = forms.models.ModelChoiceIterator
-
-    def __init__(self, null_value=0, null_label="-- None --", *args, **kwargs):
-        self.null_value = null_value
-        self.null_label = null_label
-        super(NullableModelMultipleChoiceField, self).__init__(*args, **kwargs)
-
-    def _get_choices(self):
-        if hasattr(self, "_choices"):
-            return self._choices
-        # Prepend the null choice to the queryset iterator
-        return itertools.chain([(self.null_value, self.null_label)], self.iterator(self))
-
-    choices = property(_get_choices, forms.ChoiceField._set_choices)
-
-    def clean(self, value):
-        # Strip all instances of the null value before cleaning
-        if value is not None:
-            stripped_value = [x for x in value if x != force_str(self.null_value)]
-        else:
-            stripped_value = value
-        super(NullableModelMultipleChoiceField, self).clean(stripped_value)
-        return value