Method clean

django/forms/models.py:1637–1652

(self, value)

        return list(self._check_values(value))

    def clean(self, value):
        value = self.prepare_value(value)
        if self.required and not value:
            raise ValidationError(self.error_messages["required"], code="required")
        elif not self.required and not value:
            return self.queryset.none()
        if not isinstance(value, (list, tuple)):
            raise ValidationError(
                self.error_messages["invalid_list"],
                code="invalid_list",
            )
        qs = self._check_values(value)
        # Since this overrides the inherited ModelChoiceField.clean
        # we run custom validators here
        self.run_validators(value)
        return qs

    def _check_values(self, value):
        """