ModelMultipleChoiceFilter does not validate GET request parameter?: ValueError if not int

[tombreit]

Problem

I have a working django-filter based ModelMultipleChoiceFilter implementation (see below).

A valid (and functional) request could be:

http://fqdn/?authors_filter=9684

But if I get a "malformed" request, say:

http://fqdn/?authors_filter=9xyz4

I get a ValueError: Field 'id' expected a number but got '9dyz4'., resulting in a ServerError with DEBUG = False.

Questions

• Where am I missing some kind of validation/sanitizing for these kind of URL GET parameters?
• How can this filter validate the type (here: integer) before trying to build a queryset filter?

Guesswork

Perhaps the ModelMultipleChoiceFilter does not handle this validation, but another filter (eg. NumberFilter) must be used in conjunction with ModelMultipleChoiceFilter (mentioned in #824 (comment))? But I did not manage to mix these two filters successfully...

Implementation

# models.py
class Author(models.Model):
    last_name = models.CharField(max_length=255)
    first_name = models.CharField(max_length=255, blank=True)

# filters.py
class PublicationFilter(django_filters.FilterSet):
    authors_filter = django_filters.ModelMultipleChoiceFilter(
        field_name='authors__id',
        to_field_name='id',
        queryset=Author.public_objects.all(),
    )

    class Meta:
        model = Publication
        strict = False
        fields = (
            'authors_filter',
        )

Versions

Django                   4.0.3
django-filter            21.1

SO

Already tried via https://stackoverflow.com/q/70659936/5071435 ....

[tombreit]

Sorry for the noise: the 500 for malformed request parameters (e.g. ?authors_filter=70--XYZ--56& instead of ?authors_filter=7056& was caused by the wrong widget I used (django_select2.forms.ModelSelect2MultipleWidget instead of django_select2.forms.Select2MultipleWidget).