I have a problem querying my geolocation data from my database in Cloud Firestore. I went through the documentation on Youtube and came to the conclusion that it will work best for me when i save the geolocation data in subcollections.
Here is my databse structure:
And if you go into one of the documents in the subcollection:
The database itself has a collection called "tourguides", with each document containing basic info like the name of the tour and the region where the tour is (both are Strings). Each of the documents then have a subcollection called "locations", where each document has the Strings "Name" and "ID" and also a geopoint with latitude and longitude data. The documents from the "Tourguides" collection are shown in a ListView. Whenever i tap on one of the entries, a map shall open where all the markers from the respective subcollection are shown.
Here is my ListView Builder:
@override
void initState() {
super.initState();
_pointsofinterest = Firestore.instance.collection('tourguides').document('sydney_downtown_guide').col lection('locations').orderBy('name').snapshots();
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: StreamBuilder<QuerySnapshot>(
stream: _pointsofinterest,
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) return new Text('Error: ${snapshot.error}');
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return new Text('Loading...');
default:
return new ListView(
children:
snapshot.data.documents.map((DocumentSnapshot document) {
return InkWell(
child: new ListTile(
title: new Text(document['name']),
subtitle: new Text(document['region']),
onTap: () {
return TourMap(
documents: snapshot.data.documents,
initialPosition: const LatLng(-33.868210, 151.208391),
mapController: _mapController,
);
},
),
);
}).toList(),
);
}
},
),
);
}
I put my map into a StatlessWidget (I am not sure. Maybe this has to be a StatefulWidget?):
class TourMap extends StatelessWidget {
const TourMap({
Key key,
@required this.documents,
@required this.initialPosition,
@required this.mapController,
}) : super(key: key);
final List<DocumentSnapshot> documents;
final LatLng initialPosition;
final Completer<GoogleMapController> mapController;
@override
Widget build(BuildContext context) {
return GoogleMap(
initialCameraPosition: CameraPosition(
target: initialPosition,
zoom: 12,
),
markers: documents
.map((document) => Marker(
markerId: MarkerId(document['placeId']),
icon: BitmapDescriptor.defaultMarker,
position: LatLng(
document['geolocation'].latitude,
document['geolocation'].longitude,
),
infoWindow: InfoWindow(
title: document['location_name'],
),
))
.toSet(),
onMapCreated: (mapController) {
this.mapController.complete(mapController);
},
);
}}
Now i dont exactly know how to set up the query in my OnTap function. The Firestore documentation showed that i always have to refer to specfic documents if i go down the collections from my database.
For example (collection/document/collecion). But in my query, the "document" in the middle of the path is always different, depending on which tourguide the user clicks.
Any ideas on that? Looking Forward to your replies!
UPDATE: I slightly configured my database structure! I now use two seperate databases. One database holds information about the available tourguides (just two Strings currently: Name and Region) and the other stores the actual individual Locations. I now use where-queries to get the correct locations based on the tourguide´s Name they´re belonging to.
The query itself works on the OnTap function now:
return new ListView(
children:
snapshot.data.documents.map((DocumentSnapshot document) {
return InkWell(
child: new ListTile(
title: new Text(document['name']),
subtitle: new Text(document['region']),
onTap: () {
Firestore.instance.collection('locations').where(
"toActivity",
isEqualTo: document['name'],
)
.snapshots()
.listen((data) =>
data.documents.forEach((doc) => print(doc["location_name"])));
},
),
);
}).toList(),
);
The database structure:
The correct entries are printed into the console if i tap on one of the entries in the ListView. But i will need a Google Map to pop up that shows the appropriate markers based on the "geolocation" values from the database.
