Parse.com get users nearby - ios

Question

i need to get a list of f.e the 15 nearest users using my app. The current location of the current user is stored like this:
PFGeoPoint *currentLocation = [PFGeoPoint geoPointWithLocation:newLocation];
PFUser *currentUser = [PFUser currentUser];
[currentUser setObject:currentLocation forKey:#"location"];
[currentUser saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
if (!error)
{
NSLog(#"Saved Users Location");
}
}];
Now i'd like to retrieve the users nearby via PFQuery like so:
- (NSArray *)findUsersNearby:(CLLocation *)location
{
PFGeoPoint *currentLocation = [PFGeoPoint geoPointWithLocation:location];
PFQuery *locationQuery = [PFQuery queryWithClassName:#"User"];
[locationQuery whereKey:#"location" nearGeoPoint:currentLocation withinKilometers:1.0];
locationQuery.limit = 15;
NSArray *nearbyUsers = [locationQuery findObjects];
return nearbyUsers;
}
Unfortunately it won't work. My array seems to have no entries. Can somebody clear things up for me, how the use the query the right way ?
Cheers, David
(also posted at: https://www.parse.com/questions/pfquery-to-retrieve-users-nearby)

Answer 1

First a quick comment
The code for creating a geo point is a "long running process" you will probably see this appearing in the console as you are running it on the main thread. This means the app is blocked (frozen) until the geo point is returned.
You would be better off using the code...
[PFGeoPoint geoPointForCurrentLocationInBackground:^(PFGeoPoint *geoPoint, NSError *error) {
// Now use the geopoint
}];
This is the same for the findObjects query. You should be using...
[locationQuery findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
// use the objects
}];
Actual answer
I imagine this is a read access issue. As you are accessing the User table which, by default, has no public read access.
Are you setting the default read access in the app delegate something like this...
PFACL *defaultACL = [PFACL ACL];
[defaultACL setPublicReadAccess:YES];
[PFACL setDefaultACL:defaultACL withAccessForCurrentUser:YES];
Also, maybe try loosening off the constraints. 1km is a very small radius to be checking.
Ah, something else I just spotted. [PFQuery queryWithClassName:#"User"]; is using the wrong class name.
It should be #"_User".
However, a better solution would be to use the class to generate the query...
PFQuery *userQuery = [PFUser query];
When you subclass the PFObject class properly it has this method which will generate the correct query for you.