Geofire - not found locations

Question

How can I get the all locations that are near to a passed GeoLocation(double lat, double lng) using Geo Queries. I have the following code (and it happens nothing):

public void setCurrentLatLng(double lat, double lng){
    this.lat = lat;
    this.lng = lng;
    GeoLocation geoLocation = new GeoLocation(lat, lng);
    updateCurrenLocation(geoLocation);
    GeoQuery geoQuery = geoFire.queryAtLocation(geoLocation, 8f);
    geoQuery.addGeoQueryDataEventListener(new GeoQueryDataEventListener() {

        @Override
        public void onDataEntered(DataSnapshot dataSnapshot, GeoLocation location) {
            Log.d("geoQuery","onDataEntered "+dataSnapshot.toString());
            // ...
        }

        @Override
        public void onDataExited(DataSnapshot dataSnapshot) {
            Log.d("geoQuery","onDataExited "+dataSnapshot.toString());
            // ...
        }

        @Override
        public void onDataMoved(DataSnapshot dataSnapshot, GeoLocation location) {
            Log.d("geoQuery","onDataMoved "+dataSnapshot.toString());
            // ...
        }

        @Override
        public void onDataChanged(DataSnapshot dataSnapshot, GeoLocation location) {
            Log.d("geoQuery","onDataChanged "+dataSnapshot.toString());
            // ...
        }

        @Override
        public void onGeoQueryReady() {
            // ...
            Log.d("geoQuery","onGeoQueryReady");
        }

        @Override
        public void onGeoQueryError(DatabaseError error) {
            Log.d("geoQuery","onGeoQueryError");
            // ...
        }

    });
    this.setChanged();
    notifyObservers();
    this.clearChanged();
    Log.d("update","clearChanged");
}

And this is my firebase data:

I think I'm open to modify the data struct if needed.

Logs

09-12 08:55:33.818 17710-17710/es.rchampa.weirdo D/geoQuery: lat=40.4430883 lng=-3.721805
09-12 08:55:33.982 17710-17710/es.rchampa.weirdo D/geoQuery: lat=40.4430883 lng=-3.721805
09-12 08:55:33.986 17710-17710/es.rchampa.weirdo D/geoQuery: onGeoQueryReady
09-12 08:55:34.025 17710-17710/es.rchampa.weirdo D/geoQuery: onGeoQueryReady

Gradle file

....
// Firebase
implementation 'com.google.firebase:firebase-database:16.0.1'
implementation 'com.google.firebase:firebase-storage:16.0.1'
implementation 'com.google.firebase:firebase-auth:16.0.3'
implementation 'com.google.firebase:firebase-crash:16.2.0'
implementation 'com.google.firebase:firebase-core:16.0.3'

// Firebase UI
implementation 'com.firebaseui:firebase-ui-database:1.2.0'

//Firebase GeoFire
implementation 'com.firebase:geofire-android:2.3.1'

// Google Play Services
implementation 'com.google.android.gms:play-services-auth:16.0.0'
implementation 'com.google.android.gms:play-services-maps:15.0.1'
implementation 'com.google.android.gms:play-services-location:15.0.1'
....

UPDATE

I can grant access to my private repo if you wish.

Barfuss

Have you tried to log the error from onGeoQueryError() method? What does it print? – Footpace

@AlexMamo I've updated the code to add logs. Only onGeoQueryReady is executed. Any help? – Barfuss

I think the way you have designed the database is creating problems. https://mcmap.net/q/1622694/-storing-extra-data-under-geofire-nodes – Pontificate

Can you add some logs for lat, lng, geolocation, as well as geoquery and POST the log here. – Cherlynchernow

@Pontificate the design got no problem medium.com/google-cloud/… – Cherlynchernow

@AngusTay done. – Barfuss

@ricardo, Database should be designed as i.sstatic.net/CrPRQ.jpg – Pontificate

@ricardo, can you post the code where you have set up geoFire object? – Pontificate

Don't worry about the data structure, nothing wrong and it's common – Cherlynchernow

Correct me if I'm wrong, you want to show all the other users that are located 8km around the current user location right? – Cherlynchernow

@AngusTay right! – Barfuss

So the actual problem now is displaying users around? The current location is updated in the database? – Cherlynchernow

@Barfuss just added a working example. – Greg

Answer 1

you pass value 8f (float) as the radius there, while the the radius should rather be 8.0d or Double.valueOf(8.0), where MAX_SUPPORTED_RADIUS equals 8587 kilometers.

while the actual problem is, that GeoFire already would need to know of .child("location"), but it is not possible to represent that with a Reference; only DataSnapshot has getChildren().

the bottom line is:

you'd have to create a separate locations Reference, in order to avoid the nesting. nevertheless you still can use the related uid key for these nodes (or at least add it as a child-node), in order to be able to look up within the users Reference. it's a 1:1 relation, in between two References.

so here's a working Java example, just because ...

we're assuming the following structure (as described above):

{
  "locations" : {
    "CR88aa9gnDfJYYGq5ZTMwwC38C12" : {
      ".priority" : "9q8yywdgue",
      "g" : "9q8yywdgue",
      "l" : [ 37.7853889, -122.4056973 ]
    }
  },
  "users" : {
    "CR88aa9gnDfJYYGq5ZTMwwC38C12" : {
      "displayName" : "user 01",
      ...
    }
  }
}

the database rules should have .indexOn for locations field g set:

{
  "rules": {
    ...
    "locations": {
      ".indexOn": "g"
    }
  }
}

the dependencies in the module's build.gradle:

dependencies {
    ...
    implementation "com.firebase:geofire-android:2.3.1"
}

and this demonstrates, how to obtain a user's snapshot by a GeoQuery result;

notice the GeoQueryEventListener instead of the GeoQueryDataEventListener:

public class GeofireActivity extends AppCompatActivity {

    private static final String LOG_TAG = GeofireActivity.class.getSimpleName();

    private DatabaseReference refBase     = null;
    private DatabaseReference refLocation = null;
    private DatabaseReference refUser     = null;

    private GeoFire geoFire = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.fragment_geofire);
        this.setReferences();
    }

    private void setReferences() {
        this.refBase = FirebaseDatabase.getInstance().getReference();
        this.refUser = refBase.child("users");
        this.refLocation = refBase.child("locations");
        this.geoFire = new GeoFire(this.refLocation);
    }

    private void searchNearby(double latitude, double longitude, double radius) {
        this.searchNearby(new GeoLocation(latitude, longitude), radius);
    }

    private void searchNearby(GeoLocation location, double radius) {

        GeoQuery geoQuery = this.geoFire.queryAtLocation(location, radius);
        geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {

            @Override
            public void onKeyEntered(String key, GeoLocation location) {

                String loc = String.valueOf(location.latitude) + ", " + String.valueOf(location.longitude);
                Log.d(LOG_TAG, "onKeyEntered: " + key + " @ " + loc);

                /* once the key is known, one can lookup the associated record */
                refUser.child(key).addListenerForSingleValueEvent(new ValueEventListener() {

                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                        Log.d(LOG_TAG, "onDataChange: " + dataSnapshot.toString());
                    }

                    @Override
                    public void onCancelled(@NonNull DatabaseError firebaseError) {
                        Log.e(LOG_TAG, "onCancelled: " + firebaseError.getMessage());
                    }
                });
            }

            @Override
            public void onKeyExited(String key) {
                Log.d(LOG_TAG, "onKeyExited: " + key);
            }

            @Override
            public void onKeyMoved(String key, GeoLocation location) {
                Log.d(LOG_TAG, "onKeyMoved: " + key);
            }

            @Override
            public void onGeoQueryReady() {
                Log.d(LOG_TAG, "onGeoQueryReady");
            }

            @Override
            public void onGeoQueryError(DatabaseError error) {
                Log.e(LOG_TAG, "onGeoQueryError" + error.getMessage());
            }
        });
    }
}

in order to maintain the integrity, one would need to remove the associated location record, when a user record is being removed - else it would result in keys, which cannot be looked up anymore.

Greg

I've updated the post because still can't find locations. – Barfuss

@Barfuss which version of the library do you use and which listener? your code still uses the GeoQueryDataEventListener and I think there is a difference in between the GeoFire v1 and v2 libraries (that's why I posted the example code as well, which works for me). – Greg

I'm using: com.firebase:geofire-android:2.3.1 – Barfuss

@Barfuss try implementing the GeoQueryEventListener instead, which has whole other events - and a whole other meaning; the other one GeoQueryDataEventListener is good for being notified of server-side changes, eg. when another client changes the data. – Greg

My bad. I was using a wrong path reference. Now is working! Thanks. – Barfuss

Answer 2

As it stands right now geofire sort of serves as an index to make geoqueries on, and provides the key of the document you want (which would be stored in a separate "collection").

You should be using geofire and a separate "collection" (call it usersLocations)

DatabaseReference ref = FirebaseDatabase.getInstance().getReference("usersLocations");
GeoFire geoFire = new GeoFire(ref);

Now you can use it as an index for your users, and can add items to it like so.

geoFire.setLocation('QymlMpC0Zc', new GeoLocation(40.2334983, -3.7185183));

Your Firebase RTDB will look like this now:

{
   'users': {
        'QymlMpC0Zc': {
            // All your data here
        }
    },
   'usersLocations': {
        'QymlMpC0Zc': {
            'g': 'ezjkgkk305',
            'l': {
                '0': 40.2334983,
                '1': -3.7185183
            }
        }
    }
}

So finally when you do a query on your geoFire you'll end up being firing whatever listeners you have.

As a small note... I am not a Java developer, but I do use/know geofire in general. Hopefully my bits of advice/thoughts will be helpful.

Roane

I've updated the post because still can't find locations. – Barfuss

Answer 3

The Problem is When You Passed Radius According to Issue https://github.com/firebase/geofire-java/issues/72

    double radius = 8589; // Fails
//  double radius = 8587.8; //Passes

try to pass value like this this may helps

//GeoQuery geoQuery = geoFire.queryAtLocation(geoLocation, 8f);
GeoQuery geoQuery = geoFire.queryAtLocation(geoLocation, radius);

passing value 8f (float) as the radius, while the the radius should rather be 8.0d or Double.valueOf(8.0), where MAX_SUPPORTED_RADIUS equals 8587 kilometers.

Corded

I've updated the post because still can't find locations. – Barfuss