Filter StreamBuilder snapshot data - flutter - flutter

Question

When the user enters 1st value and 2nd value and clicks the submit button, StreamBuilder should output the data between the values (age filter). How to do this?
Here is picture of display. and my code - below the picture
Full page code:
class TestScreen extends StatefulWidget {
const TestScreen({super.key});
#override
State<TestScreen> createState() => _TestScreenState();
}
class _TestScreenState extends State<TestScreen> {
final _firstTextController = TextEditingController();
final _secondTextController = TextEditingController();
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(),
body: SafeArea(
child: StreamBuilder(
stream: FirebaseFirestore.instance
.collection("users")
// .orderBy("accountCreated")
.where("activeStatus", isEqualTo: "active")
// .where("uid", isNotEqualTo: FirebaseAuth.instance.currentUser!.uid)
.snapshots(),
builder: (context, AsyncSnapshot<QuerySnapshot> streamSnapshot) {
if (streamSnapshot.connectionState == ConnectionState.waiting ||
!streamSnapshot.hasData) {
return const Center(
child: CircularProgressIndicator(),
);
}
return ListView.builder(
itemCount: streamSnapshot.data!.docs.length + 1,
itemBuilder: (context, index) {
if (index == 0) {
return Column(
children: <Widget>[
Padding(
padding: const EdgeInsets.all(8.0),
child: TextField(
controller: _firstTextController,
decoration: const InputDecoration(
hintText: "from",
),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextField(
controller: _secondTextController,
decoration: const InputDecoration(
hintText: "to",
),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: TextButton(
onPressed: () {
print("First value: ${_firstTextController.text}");
print(
"Second value: ${_secondTextController.text}");
},
child: const Text("Submit"),
),
),
],
);
} else {
return Text(
streamSnapshot.data!.docs[index - 1]["displayName"]);
}
},
);
},
),
),
);
}
}

Answer 1

class TestScreen extends StatefulWidget {
const TestScreen({super.key});
#override
State<TestScreen> createState() => _TestScreenState();
}
class _TestScreenState extends State<TestScreen> {
int userLowerValue = 20;
int userUpperValue = 60;
Stream<QuerySnapshot> getDataStream(int lower, int upper) {
return FirebaseFirestore.instance
.collection("users")
.where("age", isGreaterThan: lower)
.where("age", isLessThan: upper)
.snapshots();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
actions: [
IconButton(
onPressed: () {
int lower = 20;
int upper = 60;
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text("Enter Filter Values"),
content: SingleChildScrollView(
child: ListBody(
children: <Widget>[
TextFormField(
keyboardType: TextInputType.number,
decoration:
InputDecoration(labelText: "Lower Value"),
onChanged: (value) {
lower = int.parse(value);
},
),
TextFormField(
keyboardType: TextInputType.number,
decoration:
InputDecoration(labelText: "Upper Value"),
onChanged: (value) {
upper = int.parse(value);
},
),
],
),
),
actions: <Widget>[
TextButton(
child: Text("Apply"),
onPressed: () {
Navigator.of(context).pop();
setState(() {
userLowerValue = lower;
userUpperValue = upper;
});
},
),
],
);
},
);
},
icon: const Icon(Icons.filter))
],
),
body: SafeArea(
child: StreamBuilder(
stream: getDataStream(userLowerValue, userUpperValue),
builder: (context, AsyncSnapshot<QuerySnapshot> streamSnapshot) {
if (streamSnapshot.connectionState == ConnectionState.waiting ||!streamSnapshot.hasData) {
return const Center(
child: CircularProgressIndicator(),
);
}
if (streamSnapshot.data!.docs.isEmpty) {
return const Center(
child: CustomText(
text: "No results found",
size: 30,
),
);
}
return ListView.builder(
itemCount: streamSnapshot.data!.docs.length,
itemBuilder: (context, index) {
return Text(streamSnapshot.data!.docs[index]["displayName"]);
},
);
},
),
),
);
}
}