models.py

from django.db import models
from django.contrib.auth.models import AbstractUser
from django.conf import settings


class User(AbstractUser):
    """Custom user model for future extension"""


class BalanceType(models.Model):
    """Defines the available types a Balance instance can use"""

    name = models.CharField(max_length=settings.CHAR_FIELD_MAX_LENGTH)

    def __str__(self):
        return "%s" % self.name


class Balance(models.Model):
    """Store generic balance for an user, carry its own type"""

    type = models.ForeignKey('BalanceType', on_delete=models.CASCADE)
    value = models.IntegerField()

    user = models.ForeignKey('User', on_delete=models.CASCADE)

    def __str__(self):
        return "'%s': %s=%d " % (self.user, self.type, self.value)

serializers.py

from django.contrib.auth.models import Group
from django.contrib.auth import get_user_model
from rest_framework import serializers


class UserSerializer(serializers.HyperlinkedModelSerializer):
    """Serialize users data, return username, email, URL and groups"""

    class Meta:
        model = get_user_model()
        fields = ('url', 'username', 'email', 'groups')
        extra_kwargs = {'url': {'view_name': 'authenticator:user-detail'},
                        'groups': {'view_name': 'authenticator:group-list', 'lookup_field': 'name'} ,
        }


class GroupSerializer(serializers.HyperlinkedModelSerializer):
    """Serialize users data, return username, email, URL and groups"""

    class Meta:
        model = Group
        fields = ('url', 'name')
        extra_kwargs = {'url': {'view_name': 'authenticator:group-detail'}}

server-error.txt

(tas) ada@fse ~/development/tsa-as/src $ fg
[1]+ running: ./manage.py runserver 0.0.0.0:8000 (17193)
Internal Server Error: /api/users/
Traceback (most recent call last):
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 882, in _resolve_lookup
    current = current[bit]
TypeError: 'BoundField' object is not subscriptable

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/relations.py", line 375, in to_representation
    url = self.get_url(value, self.view_name, request, format)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/relations.py", line 313, in get_url
    return self.reverse(view_name, kwargs=kwargs, request=request, format=format)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/reverse.py", line 50, in reverse
    url = _reverse(viewname, args, kwargs, request, format, **extra)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/reverse.py", line 63, in _reverse
    url = django_reverse(viewname, args=args, kwargs=kwargs, **extra)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/urls/base.py", line 91, in reverse
    return force_text(iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs)))
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/urls/resolvers.py", line 497, in _reverse_with_prefix
    raise NoReverseMatch(msg)
django.urls.exceptions.NoReverseMatch: Reverse for 'group-list' with keyword arguments '{'pk': 1}' not found. 2 pattern(s) tried: ['api/groups\\.(?P<format>[a-z0-9]+)/?$', 'api/groups/$']

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/core/handlers/exception.py", line 41, in inner
    response = get_response(request)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/core/handlers/base.py", line 217, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/core/handlers/base.py", line 215, in _get_response
    response = response.render()
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/response.py", line 107, in render
    self.content = self.rendered_content
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/response.py", line 72, in rendered_content
    ret = renderer.render(self.data, accepted_media_type, context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/renderers.py", line 703, in render
    context = self.get_context(data, accepted_media_type, renderer_context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/renderers.py", line 676, in get_context
    'post_form': self.get_rendered_html_form(data, view, 'POST', request),
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/renderers.py", line 509, in get_rendered_html_form
    return self.render_form_for_serializer(serializer)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/renderers.py", line 519, in render_form_for_serializer
    {'style': {'template_pack': 'rest_framework/horizontal'}}
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/renderers.py", line 371, in render
    return template_render(template, context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/compat.py", line 340, in template_render
    return template.render(context, request=request)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/backends/django.py", line 66, in render
    return self.template.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 207, in render
    return self._render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 199, in _render
    return self.nodelist.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 990, in render
    bit = node.render_annotated(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 957, in render_annotated
    return self.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/defaulttags.py", line 216, in render
    nodelist.append(node.render_annotated(context))
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 957, in render_annotated
    return self.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/defaulttags.py", line 322, in render
    return nodelist.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 990, in render
    bit = node.render_annotated(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 957, in render_annotated
    return self.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/library.py", line 203, in render
    output = self.func(*resolved_args, **resolved_kwargs)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/templatetags/rest_framework.py", line 91, in render_field
    return renderer.render_field(field, style)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/renderers.py", line 350, in render_field
    return template_render(template, context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/compat.py", line 340, in template_render
    return template.render(context, request=request)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/backends/django.py", line 66, in render
    return self.template.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 207, in render
    return self._render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 199, in _render
    return self.nodelist.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 990, in render
    bit = node.render_annotated(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 957, in render_annotated
    return self.render(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 1040, in render
    output = self.filter_expression.resolve(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 708, in resolve
    obj = self.var.resolve(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 849, in resolve
    value = self._resolve_lookup(context)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/django/template/base.py", line 890, in _resolve_lookup
    current = getattr(current, bit)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/utils/serializer_helpers.py", line 70, in __getattr__
    return getattr(self._field, attr_name)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/relations.py", line 523, in choices
    return self.get_choices()
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/relations.py", line 519, in get_choices
    return self.child_relation.get_choices(cutoff)
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/relations.py", line 193, in get_choices
    for item in queryset
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/relations.py", line 193, in <listcomp>
    for item in queryset
  File "/home/ada/.virtualenvs/tas/lib/python3.5/site-packages/rest_framework/relations.py", line 390, in to_representation
    raise ImproperlyConfigured(msg % self.view_name)
django.core.exceptions.ImproperlyConfigured: Could not resolve URL for hyperlinked relationship using view name "authenticator:group-list". You may have failed to include the related model in your API, or incorrectly configured the `lookup_field` attribute on this field.
[25/May/2017 16:50:56] "GET /api/users/ HTTP/1.1" 500 295085

urls.py

from django.conf.urls import include, url
from rest_framework import routers
from pprint import pprint

from . import views


app_name = 'authenticator'

router = routers.DefaultRouter()
router.register(r'users', views.UserViewSet)
router.register(r'groups', views.GroupViewSet)

pprint(router.get_urls())

urlpatterns = [
    url(r'^$', views.BalanceView.as_view(), name='root'),
    url(r'^index$', views.BalanceView.as_view(), name='index'),
    url(r'^api/', include(router.urls)),
    url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework')),
]

views.py

from django.shortcuts import render
from django.views.generic import ListView
from django.contrib.auth.mixins import LoginRequiredMixin
from django.contrib.auth.models import Group
from django.contrib.auth import get_user_model
from rest_framework import viewsets

from .models import Balance
from .serializers import UserSerializer, GroupSerializer



# Front-end views

class BalanceView(LoginRequiredMixin, ListView):
    """Displlay balances for current user, require authentication"""

    model = Balance


# API views

class UserViewSet(viewsets.ModelViewSet):
    """Allow users to be viewed or edited"""

    User = get_user_model()
    queryset = User.objects.all().order_by('-date_joined')
    serializer_class = UserSerializer


class GroupViewSet(viewsets.ModelViewSet):
    """Allow groups to be viewed or edited"""

    queryset = Group.objects.all()
    serializer_class = GroupSerializer