query geoflutterfire as firestore - firebase

Question

I am trying to query firebase with the following requirements:
If I have a location, I want to receive the data in a certain radius through the GeoFlutterfire plugin.
If I don't have a location, I want to receive data with a limit.
I don't know if I do it correctly, but I am having problems preparing the stream.
With firestore's .snapshot() method, I get a Stream<QuerySnapshot>, but with Geoflutterfire's collection(...).Within(...) method, I get a Stream <List <DocumentSnapshot>>. This gives me trouble when trying to display the data.
If anyone can clear my mind, I would be very grateful.
Thanks in advance.
Consumer<LocationProvider>(
builder: (_, location, __) {
if (location.loading) {
return Center(
child: CircularProgressIndicator(),
);
}
final ref =
FirebaseFirestore.instance.collection("publicaciones");
Stream<List<DocumentSnapshot>> stream;
final pos = location.direccion?.geoPoint;
if (pos != null) {
final geo = Geoflutterfire();
stream = geo.collection(collectionRef: ref).within(
center: geo.point(
latitude: pos.latitude,
longitude: pos.longitude,
),
field: "direccion.geoHash",
radius: radio,
);
}
return StreamBuilder(
stream: stream ?? ref.snapshots(),
builder: (context, snapshot) {
if (snapshot.hasError) {
print(
"Error recibiendo publicaciones cercanas: ${snapshot.error}");
return Text("Error recibiendo publicaciones.");
}
if (snapshot.hasData) {
final List<Publicacion> publicaciones = snapshot.data
.map((p) => Publicacion.fromSnapshot(p))
.toList();
if (publicaciones.length == 0) {
return Text("No hay publicaciones cercanas.");
}
return ListView.builder(
shrinkWrap: true,
itemCount: publicaciones.length,
itemBuilder: (BuildContext context, int index) {
return Text(publicaciones[index].titulo);
},
);
}
return Center(
child: CircularProgressIndicator(),
);
},
);
},
)
PS: I know that stream: stream ?? ref.snapshots() is not the best way to program, but my head is a bit clouded today, sorry.
I don't know if the title of the post describes my problem, so if you can think of a better one, I'll change it.
SOLUTION:
Thanks to William Cardenas I have restructured my code as follows:
final ref =
FirebaseFirestore.instance.collection("publicaciones");
final pos = location.direccion?.geoPoint;
Stream<List<Publicacion>> stream;
if (pos != null) {
final geo = Geoflutterfire();
stream = geo
.collection(collectionRef: ref)
.within(
center: geo.point(
latitude: pos.latitude,
longitude: pos.longitude,
),
field: "direccion.geoHash",
radius: radio,
)
.map<List<Publicacion>>(
(snap) =>
snap.map((s) => Publicacion.fromSnapshot(s)).toList(),
);
} else {
stream = ref.snapshots().map<List<Publicacion>>((snap) =>
snap.docs.map((s) => Publicacion.fromSnapshot(s)).toList());
}
Then I used my stream:
return StreamBuilder<List<Publicacion>>(
stream: stream,
builder: (context, snapshot) {...

Answer 1

Map returns and iterable so we have to remember to add the "toList()" at the end.
With the Stream<List<DocumentSnapshots>> we could continue mapping the snapshots to a specific model class by the following:
stream.map((snapshot) {final data = snapshot.data();
return data != null ? Publicacion.fromSnapshot(data)
: null
}).toList();
And then try your streambuilder with something like this:
StreamBuilder<List<Publicacion>>(
stream: stream, builder: (context, snapshot) {
if(snapshot.hasData) { final pubs = snapshot.data;
final children = pubs.map((pub) =>
Text(pub.name)).toList();
return ListView(children: children);
} return Center(child: CircularProgressIndicator());
} if(snapshot.hasError){ return Center(child:
Text('Some error occurred'));
}return Center(child: CircularProgressIndicator());
)
In general do the data conversions before calling the streambuilder.