from django.forms import NullBooleanField, TypedChoiceField

class StrictBooleanField(TypedChoiceField):

    def __init__(self, *args, coerce=lambda val: bool(val), empty_value='', **kwargs):
        super().__init__(*args, coerce=coerce, empty_value=empty_value, **kwargs)
        
    def to_python(self, value):
        """
        Explicitly validate empty / missing values, otherwise normal conversion
        """
        value = NullBooleanField.to_python(self, value)
        if value is None:
            raise ValidationError(_('Invalid Boolean value %(value)s'), params={'value': value}, code='invalid')          

        return value