How to filter serializers.SlugRelatedField queryset using model field

Question

I am having trouble filtering the possible options for a SlugRelatedField using the queryset parameter. Here is my serializer

class AttendeeProfileSerializer(serializers.HyperlinkedModelSerializer):
    """
    Profile Serializer
    """
    user = serializers.SlugRelatedField(slug_field='username', queryset=User.objects.all())
    module = serializers.SlugRelatedField(slug_field='id', queryset=AttendeeModule.objects.all())
    picture = serializers.ImageField(allow_empty_file=False, required=False)

    class Meta:
        model = AttendeeProfile
        fields = (
            'user', 'module', 'title', 'company', 'email', 'picture', 'is_active', 'created'
        )

I would like to filter the module field though, a la serializers.SlugRelatedField(slug_field='id', queryset=AttendeeModule.objects.filter(module__app='module__app') or something similar where each module belongs to an app.

I imagine I need to provide more context to the serializer through the view? Should I be overriding a method on the view? I've tried but I'm still new to Django rest framework and it's giving me a lot of trouble

The view is

class AttendeesList(generics.ListCreateAPIView):
    """

    """
    queryset = AttendeeProfile.objects.all()
    serializer_class = AttendeeProfileSerializer

And using this route

url(r'^apps/(?P<url_name>[a-z][a-z0-9]+)/modules/(?P<module_id>[0-9]+)/attendees$',
    views.AttendeesList.as_view(),
    name='attendees-list'),

Answer 1

So I found a solution to my ancient question:

class SlugRelatedModuleField(SlugRelatedField):

    def get_queryset(self):
        queryset = self.queryset
        if hasattr(self.root, 'app_id'):
            queryset = queryset.filter(module__app_id=self.root.app_id)
        return queryset

class AttendeeProfileSerializer(ModelSerializer):

    def __init__(self, *args, **kwargs):
        self.app_id = kwargs.pop('app_id')
        super().__init__(*args, **kwargs)

    module = SlugRelatedModuleField(
        slug_field='id', 
        queryset=AttendeeModule.objects.all()
    )

    class Meta:
        model = AttendeeProfile
        fields = ('user', 'module', 'title', 'company', 'email', 'picture', 'is_active', 'created')

This assigns an app_id attribute on the parent/root serializer, and the SlugRelatedModuleField inspects the parent to filter the queryset. Tada.