tastypie check for missing fields in json - django

Question

I am creating an api using tastypie. Code is as follows. I have inspected code using ipdb.
class UserProfileResource(ModelResource):
class Meta:
queryset = User.objects.all()
resource_name = 'userprofiles'
excludes = ['password', 'is_active', 'is_staff', 'is_superuser']
filtering = {
'username': ALL,
}
class UserResource(ModelResource):
user = fields.ForeignKey(UserProfileResource, 'user', full=True)
class Meta:
queryset = User.objects.all()
resource_name = 'users'
list_allowed_methods = ['get','post']
allowed_methods = ['get', 'put', 'patch', 'delete']
authentication = ApiKeyAuthentication()
serializer = Serializer(formats=['json', 'jsonp', 'xml', 'yaml', 'html', 'plist'])
def post_list(self, request, **kwargs):
print 'post list method'
mandatory_fields = ['username', 'email', 'first_name', 'last_name', 'address', 'city', 'pin']
fields_apicall = request.GET.keys()
#import ipdb;ipdb.set_trace();
print request.POST
if set(mandatory_fields).issubset(fields_apicall):
print request.GET.keys()
create_object = True
else:
print 'NO'
err_dict = { 'error':'Mandatory Fields Missing.' }
return HttpResponse(json.dumps(err_dict))
def obj_create(self, bundle, **kwargs):
print 'obj_create() '
mandatory_fields = ['username', 'email', 'first_name', 'last_name', 'address', 'city', 'pin']
fields_apicall = bundle.data.keys()
# import ipdb;ipdb.set_trace();
if set(mandatory_fields).issubset(fields_apicall):
bundle.obj = self._meta.object_class()
else:
err_dict = { 'error':'Mandatory Fields Missing.' }
return HttpResponse(json.dumps(err_dict))
I want to create nested user object, ie user object together with userprofile. For that I have to make sure all fields exists in the json. I tried overriding hydrate(),dehydrate(),and post_list() methods. Among these only post_list() get invoked on a post request.
I can check for fields in request json by overriding post_list() method but is this a good way to check for missing fields? I have googled and have gone through many SO posts but I didn't find any posts mentioning to override post_list() to check for missing fields some of them said to override hydrate(). Also is it necessary to override obj_create() method to create objects using tastypie?

Answer 1

obj_create() seems like the best place to do it. Something like this should work:
def obj_create(self, bundle, **kwargs):
mandatory_fields = ['username', 'email', 'first_name', 'last_name', 'address', 'city', 'pin']
for field_name, field_object in self.fields.items():
if field_name not in mandatory_fields:
err_dict = { 'error':'Mandatory Fields Missing.' }
return HttpResponse(json.dumps(err_dict))
super(SomeResource, self).obj_create(self, bundle, **kwargs)