How do i fetching List of Taxi Drivers on User flutter

[jacklyn01]

Hello Everyone,

I've been having error on my uber clone app on getDrivers(). the error is pointing to the DriverService and DriverModel.

E/flutter (21627): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: NoSuchMethodError: The method '[]' was called on null.
E/flutter (21627): Receiver: null
E/flutter (21627): Tried calling:
E/flutter (21627): #0      Object.noSuchMethod (dart:core-patch/object_patch.dart:54:5)
E/flutter (21627): #1      new DriverModel.fromSnapshot (package:flutter_artisan_user/models/driver.dart:59:39)
E/flutter (21627): #2      DriverService.getDrivers.. (package:flutter_artisan_user/services/drivers.dart:10:43)
E/flutter (21627): #3      MappedListIterable.elementAt (dart:_internal/iterable.dart:411:31)
E/flutter (21627): #4      ListIterator.moveNext (dart:_internal/iterable.dart:340:26)
E/flutter (21627): #5      new _GrowableList._ofEfficientLengthIterable (dart:core-patch/growable_array.dart:188:27)
E/flutter (21627): #6      new _GrowableList.of (dart:core-patch/growable_array.dart:150:28)
E/flutter (21627): #7      new List.of (dart:core-patch/array_patch.dart:50:28)
E/flutter (21627): #8      ListIterable.toList (dart:_internal/iterable.dart:211:44)
E/flutter (21627): #9      DriverService.getDrivers. (package:flutter_artisan_user/services/drivers.dart:10:60)
E/flutter (21627): #10     _MapStream._handleData (dart:async/stream_pipe.dart:213:31)
E/flutter (21627): #11     _ForwardingStreamSubscription._handleData (dart:async/stream_pipe.dart:153:13)
E/flutter (21627): #12     _rootRunUnary (dart:async/zone.dart:1362:47)
E/flutter (21627): #13     _CustomZone.runUnary (dart:async/zone.dart:1265:19)
E/flutter (21627): #14     _CustomZone.runUnaryGuarded (dart:async/zone.dart:1170:7)
E/flutter (21627): #15     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
E/flutter (21627): #16     _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271:7)
E/flutter (21627): #17     _ForwardingStreamSubscription._add (dart:async/stream_pipe.dart:123:11)
E/flutter (21627): #18     _MapStream._handleData (dart:async/stream_pipe.dart:218:10)
E/flutter (21627): #19     _ForwardingStreamSubscription._handleData (dart:async/stream_pipe.dart:153:13)
E/flutter (21627): #20     _rootRunUnary (dart:async/zone.dart:1362:47)
E/flutter (21627): #21     _CustomZone.runUnary (dart:async/zone.dart:1265:19)
E/flutter (21627): #22     _CustomZone.runUnaryGuarded (dart:async/zone.dart:1170:7)
E/flutter (21627): #23     _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
E/flutter (21627): #24     _DelayedData.perform (dart:async/stream_impl.dart:591:14)
E/flutter (21627): #25     _StreamImplEvents.handleNext (dart:async/stream_impl.dart:706:11)
E/flutter (21627): #26     _PendingEvents.schedule. (dart:async/stream_impl.dart:663:7)
E/flutter (21627): #27     _rootRun (dart:async/zone.dart:1346:47)
E/flutter (21627): #28     _CustomZone.run (dart:async/zone.dart:1258:19)
E/flutter (21627): #29     _CustomZone.runGuarded (dart:async/zone.dart:1162:7)
E/flutter (21627): #30     _CustomZone.bindCallbackGuarded. (dart:async/zone.dart:1202:23)
E/flutter (21627): #31     _rootRun (dart:async/zone.dart:1354:13)
E/flutter (21627): #32     _CustomZone.run (dart:async/zone.dart:1258:19)
E/flutter (21627): #33     _CustomZone.runGuarded (dart:async/zone.dart:1162:7)
E/flutter (21627): #34     _CustomZone.bindCallbackGuarded. (dart:async/zone.dart:1202:23)
E/flutter (21627): #35     _microtaskLoop (dart:async/schedule_microtask.dart:40:21)
E/flutter (21627): #36     _startMicrotaskLoop (dart:async/schedule_microtask.dart:49:5)
E/flutter (21627):

DriverModel

    DriverModel.fromSnapshot(DocumentSnapshot snapshot)
{
    _name = snapshot.data()[NAME];
    _id = snapshot.data()[ID];
    _occupation = snapshot.data()[OCCUPATION];
    _specialization = snapshot.data()[SPECIALIZATION];
    _photo = snapshot.data()[PHOTO];
    _phone = snapshot.data()[PHONE];
    _rating = snapshot.data()[RATING];
    _votes = snapshot.data()[VOTES];
    _position = DriverPosition
    (
        lat: snapshot.data()[POSITION][LATITUDE],
        lng: snapshot.data()[POSITION][LONGITUDE],
        heading: snapshot.data()[POSITION][HEADING]
    );
}
    LatLng getPosition() 
    {
        return LatLng(_position.lat, _position.lng);
    }
}
class DriverPosition 
{
    final double lat;
    final double lng;
    final double heading;
  
    DriverPosition({this.lat, this.lng, this.heading});
}

DriverService

class DriverService 
{
    String collection = 'drivers';
    Stream<List<DriverModel>> getDrivers()
    {
        return firebaseFiretore.collection(collection).snapshots().map((event) =>
        event.docs.map((e) => DriverModel.fromSnapshot(e)).toList());
    }
    Future<DriverModel> getDriverById(String id) =>
    firebaseFiretore.collection(collection).doc(id).get().then((doc) 
    {
        return DriverModel.fromSnapshot(doc);
    });
    Stream<QuerySnapshot> driverStream() 
    {
        CollectionReference reference = FirebaseFirestore.instance.collection(collection);
        return reference.snapshots();
    }
}

Kindly assist please, I've been on this for weeks.

[ibrierley]

I think you've posted this to the wrong place. It doesn't have anything to do with flutter_map that I can see....