DRF choices not set in MultiChoiceField serializer field

[MattFanto]

I'm using this library to provide metadata information for a frontend application, one of the field in my model is a simple M2M mapped to "static" table with 15 entries.

class Waste(models.Model):
    cer = models.CharField(verbose_name='Codice CER', null=True, blank=True, max_length=10, choices=CER_CODES)
    descr = models.CharField(verbose_name='Descrizione rifiuto', null=True, blank=True, max_length=300)
    unofficial_descr = models.CharField(verbose_name='Descrizione informale del rifiuto', null=True, blank=True, max_length=300)
    categ_rifiuto = models.CharField(verbose_name='Tipologia rifiuto', null=True, blank=True, max_length=20, choices=CHOICES_CATEG_RIF)
    haz = models.BooleanField(verbose_name='Pericoloso', default=False)  # MAYBE default None?
    hp = models.ManyToManyField(HP, verbose_name='Proprietà di pericolo', blank=True)

For that reason, in the related serializer I decided to use MultiChoiceField

class WasteSerializer(serializers.ModelSerializer):
    hp = serializers.MultipleChoiceField(choices=tuple(HP.objects.all().values_list('code', 'descr')), label='Proprietà di pericolo')

    def create(self, validated_data):
        # custom code to set hp appropriately

    class Meta:
        model = Waste
        fields = '__all__'

Unfortunately the available choices are not rendered in the metadata response, the reason is that drf_auto_endpoint.get_field_dict.GetFieldDict.update_choices_from_serializer only recognize ChoiceField as a field for which choices should be populated

    def update_choices_from_serializer(self, rv, field_instance, force=False):
        if field_instance.__class__.__name__ != 'ChoiceField' and force is False:
            return # --> in my case the field is of type 'MultiChoiceField'

        if not hasattr(field_instance, 'choices'):
            return

        if rv.get('related_endpoint', None) is not None and force is False:
            return

        rv['type'] = settings.WIDGET_MAPPING['choice']
        rv['choices'] = [
            {
                'label': v,
                'value': k,
            } for k, v in field_instance.choices.items()
        ]

For this field the rendered metadata is the following (which is not particularly useful for the frontend)

  {
    "key": "hp",
    "type": "manytomany-lists",
    "read_only": false,
    "ui": {
      "label": "Proprietà di pericolo"
    },
    "validation": {
      "required": true
    },
    "extra": {},
    "translated": false,
    "related_endpoint": {
      "app": "core",
      "singular": "hp",
      "plural": "hps"
    }

Thanks,
Mattia

[nanuxbe]

Thanks for the report and your patience. I will look into the possible fixes for this. Using isinstance instead of relying on __class__.__name__ sounds like it should work but I will have to investigate the Django inheritance scheme for those fields.