django - Can't exclude ForeignKey fields for User in Piston -

i have model:

# models.py django.contrib.auth.models import user  class test(models.model):     author = models.foreignkey(user, related_name="tests")     title = models.charfield(_("title"), max_length=100) 

then in api folder django piston webservice:

class testhandler(basehandler):     allowed_methods = ("get")     model = test     fields = ("title", ("author", ("username",)))      def read(self, request, id):         base = self.model.objects         try:             r = base.get(pk=id)             return r         except:             return rc.not_found 

if call webservice get:

{     "title": "a test"     "author": {         "username": "menda",          "first_name": "",          "last_name": "",          "is_active": true,          "is_superuser": true,          "is_staff": true,          "last_login": "2011-02-09 10:39:02",          "password": "sha1$83f15$feb85449bdae1a55f3ad5b41a601dbdb35c844b7",          "email": "b@a.as",          "date_joined": "2011-02-02 10:49:48"     }, } 

i have tried use exclude, doesn't work either.

how can username author? thanks!

okay, problem piston using set of fields defined on user model handler class, rather nested fields specified here.

another user refers exact same issue on piston discussion group here:

http://groups.google.com/group/django-piston/browse_thread/thread/295de704615ee9bd

the problem apparently caused bug in piston's serialization code. in words of documentation:

by using model in handler, piston remember fields/exclude directives , use them in other handlers return objects of type (unless overridden.)

which good, except "(unless overridden.)" case doesn't seem handled correctly.

i think slight modification in emitters.py might fix issue (lines 160-193)...

if handler:     fields = getattr(handler, 'fields')                     if not fields or hasattr(handler, 'fields'):     ...dostuff... else:     get_fields = set(fields) 

which should (perhaps?) read

if fields:     get_fields = set(fields) else:     if handler:         fields = getattr(handler, 'fields')     ...dostuff... 

if decide try patching emitters.py let me know if trick - it'd patched in django-piston.

cheers!