Xtykutl

I have such models in my application:

class User(AbstractUser):

    pass





class MyObject(models.Model):

    name = models.CharField(max_length=200, unique=False, db_index=True)



    related_users = models.ManyToManyField(

        User, through='RelatedUsers', related_name='related_users'

    )





class RelatedUsers(models.Model):

    my_object = models.ForeignKey(

        MyObject, related_name='my_object_related_users'

    )

    user = models.ForeignKey(User)

    type = models.CharField(

        max_length=100,

        choices=RelatedUsersTypes.choices()

    )



    class Meta:

        unique_together = ('user', 'my_object', 'type')





class FunctionalityRelatedUsersTypes(BaseChoiceEnum):

    TYPE_1 = 'TYPE 1'

    TYPE_2 = 'TYPE 2'

    TYPE_3 = 'TYPE 3'

    TYPE_4 = 'TYPE 4'

    TYPE_5 = 'TYPE 5'

I'm wondering if there is an option to create some kind of synthetic relations on MyObject.
I would like to be able to get users by type using one field, example: related_users_type_1. I'd like to use it in DRF serializer as well (so I can pass just List of ids, and relation will create a Proxy object with the corresponding type).

Pseudocode:

related_users_type_1 = models.RelationField(RelatedUsers, filter={'type': 'TYPE_1'})

Sample payload I want to send:

{

    "related_users_type_1": [1, 2, 3],

    "related_users_type_2": [3]

}

Expected result:

• 3 RelatedUsers with TYPE_1
  


• 1 RelatedUser with TYPE_2
  

From the comments we've had, I think your problem can be solved with models as such:

# just for completeness. should probably use an actual user model

class User (models.Model):

    name = models.CharField(max_length=64)



class MyObject(models.Model):

    name = models.CharField(max_length=64)

    users = models.ManyToMany(User, through='MyObjectUsers', symmetrical=False)



    def add_relations(self, relations):

        for key, list in relations.items():

            for id in list:

                users.add(user=User.objects.get(pk=id), rel_type=key)







class MyObjectUsers(models.Model):

    REL_TYPE_CHOICES=(

        ('TYPE1','TYPE1'),

        ('TYPE2','TYPE2')

    )

    myobject = models.ForeignKey('MyObject', null=True, on_delete=models.SET_NULL)

    user = models.ForeignKey('User', null=True, on_delete=models.SET_NULL)

    rel_type = models.CharField(max_length=32, choices = REL_TYPE_CHOICES)

The django documentation shows you how to traverse the relationship.

With the above implementation of MyObject, you should be able to to call .add_relations({'TYPE1':[1,2,3]}) on a MyObject instance to create the relationships you need.

I wrote this on my phone so I don't really know if it runs (will test tomorrow)