Tastypie relationship fields on obj_get_list - tastypie

Question

I have a very standard user/group many to many relationship with the following simplified definition:
class GroupResource(ModelResource):
users = fields.ToManyField(UserResource, 'group_set')
class Meta:
cache = SimpleCache()
queryset = Group.objects.all()
resource_name = "hr/group"
When I get a list groups it returns the group along with the list of uris of users connected to the group. However, our production system is starting to get quite large and a group can have hundreds of users in it. It is becoming painstakingly slow to return a list of groups, since each group also returns with it a list of users connected to that group.
Is there a way to exclude the linked users only for obj_get_list, but include the users when viewing the group instance? Or is there another solution to this problem that will fit better?

Answer 1

You need to specify a callable as use_in argument to fields.ToManyField which returns False if current request corresponds to get_list end point.
Example code
def is_not_group_get_list_end_point(bundle):
# TODO: use dynamically generated path here.
if bundle.request.get_full_path() == '/api/v1/hr/group/':
return False
return True
class GroupResource(ModelResource):
users = fields.ToManyField(UserResource, 'group_set',
use_in=is_not_group_get_list_end_point)
class Meta:
cache = SimpleCache()
queryset = Group.objects.all()
resource_name = "hr/group"