Add custom model name lookup to fix #389

[markkuleinio]

Fixes #389

The list_parser() function in Record._parse_values() is modified to support lists of custom models, defined like this:

class Permissions(Record):
    users = [Users]

Running example:

>>> perm = list(nb.users.permissions.all())[0]
>>> pprint(dict(perm))
{'actions': ['view'],
 'constraints': {'status': 'test'},
 'description': '',
 'display': 'TestPermission',
 'enabled': False,
 'groups': [],
 'id': 1,
 'name': 'TestPermission',
 'object_types': ['circuits.circuit'],
 'url': 'http://netbox31beta.lein.io/api/users/permissions/1/',
 'users': [{'display': 'admin',
            'id': 1,
            'url': 'http://netbox31beta.lein.io/api/users/users/1/',
            'username': 'admin'}]}
>>> perm.users
[admin]
>>> type(perm.users[0])
<class 'pynetbox.models.users.Users'>
>>>

---

The original PR text left here for the memory of all the unsuccessful attempts: 😁

The model name lookup table is populated in the model source file (users.py) to prevent circular imports (we cannot import Users in response.py because users.py already imports response.py).

Works now:

>>> permission = list(netbox.users.permissions.all())[0]
>>> permission.users
[test1]
>>>

[Dimaqa]

I believe the idea was to pass return_obj to Endpoint class and implement full Permission model not only users field.
So after you define

class User:
     def __str__(self):
        return self.username

class Permission:
     users = User

     @property
     def some_usefull_property(self):
          return 42

and somehow pass Permission model to permissions Endpoint you get the same behaviour as with default defined models.
This implementation would also be really helpful with plugins integration.

[Dimaqa]

I think you just need to find a way to pass your new model to App class or modify _lookup_ret_obj in Endpoint class

[markkuleinio]

Any new comments anyone? @Dimaqa @zachmoody

Is it a problem that Permission.users is a list of User objects, not just one User?

Lost track of all these classes and models already 😄 but thinking that something needs to be figured out to support modern NetBox versions. Is it then dealing with all kinds of custom models, or fixing the __str__() output with the display field as a last resort in

pynetbox/pynetbox/core/response.py

Line 316 in 33a7fb9

return getattr(self, "name", None) or getattr(self, "label", None) or ""

(because that's the common and good enough (for me, I think now, but untested) solution for NetBox 2.11+ objects).

@Dimaqa feel free to open your own PR if you have a better fix in mind.

[markkuleinio]

Not sure how @zachmoody gets the notifications for a new commit in an existing PR so here is a ping for you 😁 (see the modified message on top of this PR)