I have method like this in my provider file to get a list of items :
Future<void> getServerMeals() async {
final QueryBuilder<ParseObject> parseQuery =
QueryBuilder<ParseObject>(ParseObject('UsersEaten'));
final ParseResponse apiResponse = await parseQuery.query();
if (apiResponse.success && apiResponse.results != null) {
List<dynamic>? apiRes = apiResponse.results;
List<EatenItem> newMeals = apiRes!
.map((e) => EatenItem(
id: e['objectId'],
eatenCal: e['eatenCal'],
eatenTitle: e['eatenTitle'],
eatenImageUrl: e['eatenImg'],
userId: e['objectId'],
))
.toList();
_eatenMeals = newMeals;
print(apiResponse.results);
notifyListeners();
}
}
and in my main screen I have a StatelessWidget and FutureBuilder to get that list :
class TimelineWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Column(
mainAxisAlignment: MainAxisAlignment.start,
children: [
Container(
child: FutureBuilder(
future: Provider.of<EatenMeals>(context, listen: false).getServerMeals(),
builder: (ctx, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(
child: CircularProgressIndicator(),
);
}
return Consumer<EatenMeals>(
builder: (ctx, mealsList, child) => ListView.builder(
itemCount: mealsList.eatenMeals.length,
itemBuilder: (ctx, index) =>
DailyEaten(mealsList.eatenMeals[index]),
),
);
},
),
),
],
);
}
as you can see there is nothing in my build method and I've tried to use Consumer as future to avoid infinite loop but it doesn't work for me please tell me what's wrong here I appreciate if u explain with code snippet
Related
I'm attempting display data from two diffrent collections within firestore , I treied to nest both streambuilds so i can particulary display the data as one stream , however I keep on getting the error bad state field doesnt exist with doc snapshot how can i fixing thus error , or is there another much more effective method i can use to display data from two diffrent collections in one class?
below is screenshot of the data(s) i want to display:
class OrderStream extends StatelessWidget {
static const String route = "/Order";
final CollectionReference meal =
FirebaseFirestore.instance.collection("menu");
final CollectionReference profile =
FirebaseFirestore.instance.collection("users");
OrderStream({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
body: StreamBuilder(
stream: profile.snapshots(),
builder: (context, AsyncSnapshot<QuerySnapshot> streamSnapshot) {
return StreamBuilder(
stream: meal.snapshots(),
builder:
(context, AsyncSnapshot<QuerySnapshot> streamSnapshot) {
if (!streamSnapshot.hasData) {
return const SizedBox(
height: 250,
child: Center(
child: CircularProgressIndicator(),
),
);
} else {
return ListView.builder(
itemCount: streamSnapshot.data!.docs.length,
itemBuilder: (context, index) {
final DocumentSnapshot documentSnapshot =
streamSnapshot.data!.docs[index];
return Column(
children: [
Text( documentSnapshot['price'],)
Text( documentSnapshot['name'],)
]
),
),
}
This is probably happening due to similar name for both snapshots.
The best way to check this is by renaming the snapshot for individual Streambuilder().
StreamBuilder(
stream: profile.snapshots(),
builder: (context, AsyncSnapshot<QuerySnapshot> profileStreamSnapshot) {
return StreamBuilder(
stream: meal.snapshots(),
builder:
(context, AsyncSnapshot<QuerySnapshot> mealStreamSnapshot) {
if (!streamSnapshot.hasData) {
//modified (renamed snapshot variable) code here
}
You can merge those two streams into 1 using library like rxdart which has combineLatest2 method although you can also use something like StreamZip to get the same effect.
I have used rxdart combineLatest2 as follows:
import 'package:rxdart/rxdart.dart';//import ⇐
class MyHomePage extends StatelessWidget {
final CollectionReference profile =
FirebaseFirestore.instance.collection("users");
final CollectionReference meal =
FirebaseFirestore.instance.collection("menu");
MyHomePage({super.key});
#override
Widget build(BuildContext context) {
return Scaffold(
body: StreamBuilder(
stream: Rx.combineLatest2(profile.snapshots(), meal.snapshots(),
(QuerySnapshot profileSnapshot, QuerySnapshot mealSnapshot) {
return [...profileSnapshot.docs, ...mealSnapshot.docs];
}),
builder: (context, AsyncSnapshot<List<DocumentSnapshot>> snapshot) {
if (!snapshot.hasData) {
return const SizedBox(
height: 250,
child: Center(
child: CircularProgressIndicator(),
),
);
} else {
return ListView.builder(
itemCount: snapshot.data!.length,
itemBuilder: (context, index) {
final DocumentSnapshot documentSnapshot =
snapshot.data![index];
final Map<String, dynamic> data =
documentSnapshot.data() as Map<String, dynamic>;
if (data.containsKey("price") && data.containsKey("name")) {
return Column(
children: [Text(data["price"]), Text(data["name"])],
);
} else {
return Container();
}
},
);
}
}),
);
}
}
You can also use Stream.merge() as follows:
final Stream<QuerySnapshot> mealsStream = meal.snapshots();
final Stream<QuerySnapshot> profilesStream = profile.snapshots();
//.. All that Scaffold stuff
stream: Stream.merge([mealsStream, profilesStream]),
class StudentProvider extends ChangeNotifier {
DataBaseHelper data = DataBaseHelper();
List<StudentModel>? student = [];
List<StudentModel>? searchStudentList;
Future<List<StudentModel>> getStudentList() async {
student = await data.getStudent();
return student!;
}
void insert(StudentModel studentModel) async {
print("reached insert in provider class");
await data.insertStudent(studentModel);
notifyListeners();
}
}
The code above is the provider class of mine and I want to use the list that I get from getStudentList list method to build widgets. The problem is it returns a future because I am getting the data from the database.
body: TabBarView(children: [
Consumer<StudentProvider>(
builder: (context, StudentProvider student, ch) {
print("rebuild happened");
return ListView(
children: [
...student.getStudentList().map((e) {
return HomeScreen(student: e);
}).toList(),
],
);
}),
This is where I am trying to build widgets. I am unable to do so.
in getStudentList() you have used Future<List<StudentModel>> so that future can not access in listview.
> So please use streambuilder or remove the future from the list
class StreamBuilderUsage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Expanded(
child: Center(
child: Consumer<StudentProvider>(
builder: (context, StudentProvider student, ch) {
return StreamBuilder(
stream: student.getStudentList().asStream(),
builder: (context, snapshot){
print(snapshot.connectionState);
if(snapshot.hasData){
var data = snapshot.data as List<String>;
return ListView.builder(
itemCount: data.length,
itemBuilder: (context, index){
return Text(data[index]);
},
);
}else{
return CircularProgressIndicator();
}
},
);
}
),
),
),
],
),
);
}
}
The answer I accepted will also work and we can use Future builder for the same.
Here is the code:-
body: TabBarView(
children: [
Consumer<StudentProvider>(
builder: (context, StudentProvider student, ch) {
print("rebuild happened");
return FutureBuilder(
future: student.getStudentList(),
builder: (context, snapshot) {
if (snapshot.hasData) {
List<StudentModel> data =
snapshot.data as List<StudentModel>;
return ListView.builder(
itemCount: data.length,
itemBuilder: (context, index) {
return HomeScreen(student: data[index]);
});
} else
return Container(child: Text("No data"));
},
);
},
),
Container(),//neglect this container
],
),
I am using streambuilder to display snapshot data but it is not displaying. The screen is just blank but When I use the future builder with get() methode it display the data but I want realtime changes. I am new to flutter please help me with this. here is code.
class TalentScreen2 extends StatelessWidget {
final Query _fetchFavUser = FirebaseRepo.instance.fetchFavUsers();
#override
Widget build(BuildContext context) {
return SafeArea(
child: Scaffold(
body: Column(
children: [
Text('Talent Screen 2(Favourites)'),
Expanded(child: _retrieveData(context))
],
),
),
);
}
Widget _retrieveData(BuildContext context) => StreamBuilder<QuerySnapshot>(
stream: _fetchFavUser.snapshots(),
builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
if (snapshot.hasError) return const Text('Something went wrong');
if (!snapshot.hasData) return const Text('Alas! No data found');
if (snapshot.connectionState == ConnectionState.waiting)
return Center(
child: CircularProgressIndicator(
strokeWidth: 2.0,
));
if (snapshot.connectionState == ConnectionState.done)
return theUserInfo(snapshot.data.docs);
return Container();
});
Widget theUserInfo(List<QueryDocumentSnapshot> data) {
return ListView.builder(
shrinkWrap: true,
itemCount: data.length,
itemBuilder: (BuildContext context, int index) {
var uid = data[index]['uid'];
TalentHireFavModel userData = TalentHireFavModel.fromMap(
data[index].data(),
);
return Card(
child: Column(
children: <Widget>[
Text(data[index]['orderBy']),
// Text(userData.name ?? ''),
Text(userData.categories),
Text(userData.skills),
// Text(userData.country ?? ''),
Text(userData.phoneNo),
Text(userData.hourlyRate),
Text(userData.professionalOverview),
Text(userData.skills),
Text(userData.expert),
// Text(userData.createdAt ?? ''),
_iconButton(userData.uid, context),
],
),
);
});
}
Future<DocumentSnapshot> fetch(data) async =>
await FirebaseRepo.instance.fetchWorkerUserData(data);
Widget _iconButton(uid, context) {
return IconButton(
icon: Icon(Icons.favorite),
onPressed: () {
BlocProvider.of<TalentFavCubit>(context).removeTalentFav(uid);
});
}
}
and here is the firestore query methode where I am just applying simple query to fetch all documents and display them. I want real-time changes
Query fetchFavUsers() {
var data = _firestore
.collection('workerField')
.doc(getCurrentUser().uid)
.collection('favourites')
// .where('uid', isNotEqualTo: getCurrentUser().uid)
.orderBy('orderBy', descending: true);
return data;
}
The solution is to just return the function. Get that method out of if statement and place it in just return statement.
At first, when i started writing my calls to get data from firestore, it worked. But when i tried writing more docs to my collection, it failed to bring data for the docs i recently added. Then, when i deleted the first one i added, i stopped receiveing data from firestore all together. I have tried several methods, but have all ended in failure.
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
class collect extends StatefulWidget {
#override
_collectState createState() => _collectState();
}
class _collectState extends State<collect>
{
Future _data;
void initState()
{
super.initState();
_data = getStuff();
}
Future getStuff()
async {
var firestore = FirebaseFirestore.instance;
QuerySnapshot qn = await firestore.collection("buses").get();
return qn.docs;
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: FutureBuilder(
future: _data,
builder: (_, snapshot)
{
if(snapshot.connectionState == ConnectionState.waiting)
{
return Center(
child:Text("Loading")
);
}
else if(snapshot.connectionState == ConnectionState.done)
{
return ListView.builder(itemCount: snapshot.data.length,itemBuilder:(_, index)
{
return Container(
child: ListTile(
title: Text(snapshot.data[index].data()["name"].toString()),
subtitle: Text(snapshot.data[index].data()["price"].toString()),
),
);
});
}
},
),
);
}
}
```
Define your database call as,
Future getStuff() async {
var docs;
await FirebaseFirestore.instance
.collection("buses")
.get()
.then((querySnapshot) {
docs = querySnapshot.docs;
});
return docs;
}
Then use the FutureBuilder in the build() function as,
return Scaffold(
body: Center(
child: FutureBuilder<dynamic>(
future: getStuff(),
builder: (BuildContext context, AsyncSnapshot<dynamic> snapshot) {
if (snapshot.hasData) {
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (_, index) {
return Container(
child: ListTile(
title: Text(
snapshot.data[index].data()["name"].toString()),
subtitle: Text(
snapshot.data[index].data()["price"].toString()),
),
);
});
} else {
return CircularProgressIndicator();
}
},
),
),
);
I wrapped the FutureBuilder inside a Center just for clarity, you may remove that Center widget.
I have a small problem, I need to retrieve into my list a collection retrieved by StreamBuilder from Firestore.
I am using snapshot.data.documents.lenght but once I add it I got error:
Class 'DocumentSnapshot' has no instance getter 'documents'.
Receiver: Instance of 'DocumentSnapshot'
Tried calling: documents
this is my code:
Stream<DocumentSnapshot> getDatabase() async* {
FirebaseUser user = await FirebaseAuth.instance.currentUser();
yield* Firestore.instance
.collection('dataCollection')
.document(user.uid)
.snapshots();
}
#override
Widget build(BuildContext context,) {
return StreamBuilder(
stream: getDatabase(),
builder: (context, snapshot,) {
if (snapshot.data != null) {
return Column(
children: <Widget>[
Container(
height: 500,
child: ListView.builder(
shrinkWrap: true,
itemCount: 2,
itemBuilder: (BuildContext context, int index) {
return Card(
color: Color(0xFF1f2032),
elevation: 15,
child: Text(
snapshot.data['phone']..
just change your code as following
Stream dataStream
then
#override
void initState() {
getDatabase().then((value) {
dataStream = value;
setState(() {});
});
super.initState();
}
the funcion getDatbase()
getDatabase() async {
FirebaseUser user = await FirebaseAuth.instance.currentUser();
yield* Firestore.instance
.collection('dataCollection')
.document(user.uid)
.snapshots();
}
then
#override
Widget build(BuildContext context,) {
return StreamBuilder(
stream: dataStream,
builder: (context, snapshot,) {
if (snapshot.data != null) {
return Column(
children: <Widget>[
Container(
height: 500,
child: ListView.builder(
shrinkWrap: true,
itemCount: 2,
itemBuilder: (BuildContext context, int index) {
return Card(
color: Color(0xFF1f2032),
elevation: 15,
child: Text(
snapshot.data['phone']..
Try this,
StreamBuilder(
stream: stream,
builder: (BuildContext context,
AsyncSnapshot<List<DocumentSnapshot>> snapshots) {
if (snapshots.connectionState == ConnectionState.active &&
snapshots.hasData) {
return Expanded(
child: ListView.builder(
scrollDirection: Axis.vertical,
shrinkWrap: true,
itemCount: snapshots.data.length,
itemBuilder: (BuildContext context, int index) {
//do something with snapshot.
}
}
return Container();
},
),
);
} else {
return Container();
}
},
),
Initialise your stream like this,
Stream<DocumentSnapshot> stream;
Future<dynamic> getDatabase() async {
FirebaseUser user = await FirebaseAuth.instance.currentUser();
setState(() {
stream=Firestore.instance
.collection('dataCollection')
.document(user.uid)
.snapshots();
});
}
You can call getDatabase() in initState.
Update:-
This is your full code.
class DataCo extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.white,
appBar: AppBar(
backgroundColor: Colors.blue,
),
body: Column(
children: [
CollectData(),
],
),
);
}
}
class CollectData extends StatefulWidget {
#override
_CollectDataState createState() => _CollectDataState();
}
class _CollectDataState extends State<CollectData> {
final String phone;
final String wife;
final String location;
_CollectDataState({this.phone, this.wife, this.location});
#override
void initState() {
super.initState();
getDatabase();
}
Stream<DocumentSnapshot> stream;
Future<dynamic> getDatabase() async {
FirebaseUser user = await FirebaseAuth.instance.currentUser();
setState(() {
stream=Firestore.instance
.collection('dataCollection')
.document(user.uid)
.snapshots();
});
}
#override
Widget build(BuildContext context,) {
return StreamBuilder(
stream: stream,
builder: (BuildContext context,
AsyncSnapshot<DocumentSnapshot> snapshots) {
if (snapshots.connectionState == ConnectionState.active &&
snapshots.hasData) {
return Expanded(
child: ListView.builder(
scrollDirection: Axis.vertical,
shrinkWrap: true,
itemCount: snapshots.data.length,
itemBuilder: (BuildContext context, int index) {
//do something with snapshot.
}
}
return Container();
},
),
);
} else {
return Container();
}
},
);
}
}
class NoData extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Column(
children: [
Text('No Data available'),
],
);
}
}