Develop Reference

I can't get a return from flutterfire realtime database emulator?

I have already done everything for the setup I'm sure. I connected my project in the firebase console, and I was able to get my app to run after an await firebase initialize (options : options...etc.) once I finished with the flutterfire CLI config.
But now I can't get the actual value from my json file in the realtime database emulator. All I can get is null. Maybe I am not referring to the json right, but my json right now is just:
{ "hello" : "hi" }
so I don't think that's the problem. This is how I'm calling the database.
final _database = FirebaseDatabase.instance.ref();
and I'm using a future builder.
child:FutureBuilder(
future: _database.child('http://{$host_number}/?ns=nimble-autumn-{$project_id_number}/hello').get(),
builder: (context, AsyncSnapshot snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
return ListView.builder(
//shrinkWrap: true,
scrollDirection: Axis.vertical,
physics: AlwaysScrollableScrollPhysics(),
itemCount: gocrazy.length,
itemBuilder: (BuildContext context, int index) {
return PostCard(
status: public[0], comments: [snapshot.toString()]);
//rags[index]);
},
);
}
else {
return Column(
children: <Widget>[
SizedBox(
width: 60,
height: 60,
child: CircularProgressIndicator(),
),
Padding(
padding: EdgeInsets.only(top: 16),
child: Text('Awaiting result...'),
),
]
);
};
And the UI will complete with the if statement because I am using .toString() and this what I get (if I use .value it will cause null error).
It says invalid Firebase Database data path. So what is the valid way to put it? I am using:
'http://{$host_number}/?ns=nimble-autumn-{$projectid}/hello'
but using 'nimble-autumn-projectid/hello' or 'hello' will just have the futurebuilder hang indefinitely.

How can I display last StreamBuilder data when snapshot.data is null?

I'm making a to-do list with Flutter and Firebase Firestore, but I have a slight problem. Whenever I add a new task, snapshot.data becomes null. If I do not add a check for snapshot.connectionState and render a different widget according to that, I get the following error: NoSuchMethodError (NoSuchMethodError: The getter 'docs' was called on null.
return StreamBuilder(
stream: FirebaseFirestore.instance
.collection('tasks')
.doc(widget.uid)
.collection('mytasks')
.snapshots(),
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return const Center(
child: SizedBox(
height: 100, width: 100, child: CircularProgressIndicator()),
);
} else {
> final docs = snapshot.data.docs;
return ListView.builder(
itemCount: docs.length,
itemBuilder: (ctx, index) {
final currTask = docs[index];
return Dismissible(
direction: DismissDirection.startToEnd,
key: UniqueKey(),
onDismissed: (_) async {
FirebaseFirestore.instance
.collection('tasks')
.doc(widget.uid)
.collection('mytasks')
.doc(currTask['id'])
.delete();
.
.
.
I don't want to have to display a CircularProgressIndicator or an empty screen. I want the tasks to remain visible and seamlessly add new tasks. How can I achieve that? I know what I asked for in the question title might be a little silly, what should I do instead?

Flutter issue: DropDown in ListView.Builder

i am getting values from server to dropdown which are inserted previous from static list of dropdown values, but i need to use dropdown when value from server is 'Pending' to update specific record, below my code.
List<String> approvalList = ['Pending', 'Approve', 'Discard'];
String dropdownValue="Pending";
Container(
height: MediaQuery.of(context).size.height*0.3,
width: MediaQuery.of(context).size.width,
child:StreamBuilder<List<ApprovalModel>>(
stream: bloc.approvalsStream,
initialData: [],
builder: (context, snapshot) {
return ListView.builder(
itemCount: snapshot.data!.length,
itemBuilder: (context,i){
return snapshot.connectionState==ConnectionState.waiting?Lottie.asset(
'assets/lottieloading.json',
width: 70,
height: 70,
fit: BoxFit.fill,
):ListTile(
title: Text(snapshot.data![i].approverName),
trailing: StatefulBuilder(
builder: (BuildContext context, StateSetter setState) {
return DropdownButton<String>(
value: snapshot.data![i].status==0?'Pending':
snapshot.data![i].status==1?'Approve':
'Discard',
items: approvalList.map((String val) {
return DropdownMenuItem<String>(
value: val,
child: new Text(val),
);
}).toList(),
hint: Text(selectedValue),
onChanged: (val) {
setState(() {
dropdownValue = val!;
});
});
}
),
);
});
}
)
,
),
As You see i am setting value from server it is working fine, but when the value is pending i want to use the dropdown to update record in database.

At onChanged when you update your dropdownValue , also call the method you are using to update record in database.

Flutter, cloud fire store query method, where not working properly

I am trying to make a search feature in an app where I search for a store (from the Cloud Firestore database) using their query method where but I keep getting the same result, which is the first store on "list". No matter what I search.
StreamBuilder(
builder: (context , snapshot) {
if(snapshot.hasError) {
return Center(
child: Text(snapshot.error.toString()),
);
}//end if
if (snapshot.hasData) {
QuerySnapshot querysnapshot = snapshot.data;
List<QueryDocumentSnapshot> documents = querysnapshot.docs;
processData(documents);
print("here : " + stores[0].name.toString());
print("search: " + searchQuery);
print("array length: " + stores.length.toString());
return Container(
child: ListView.builder(
itemBuilder: (context , index) {
return Center(
child: Text(stores[index].name.toString()),
);
},
itemCount: stores.length,
),
height: height,
);
} else {
return Container(
child: Center(
child: Text("Snapshot has no data"),
),
);
}//end if-else
},
stream: FirebaseFirestore.instance.collection('Stores').where('name' , isEqualTo: name).snapshots(),
)

sorry I made an idiotic mistake. I forgot to use to search variable instead of the name variable in the where function!

order data by timestamp in descending order from firestore

im failing to order my data by timestamp in descending order, error keeps saying have positioned it wrong
StreamBuilder(
stream: Firestore.instance.collection("payments").orderBy("timestamp", "desc").where('participants', arrayContains: userActive).snapshots(),
builder: (context, snapshot){
return Container ( child:ListView.builder(
shrinkWrap: true,
itemCount: snapshot.data.documents.length,
padding: EdgeInsets.all(0),
controller: ScrollController(keepScrollOffset: false),
itemBuilder: (context, index){
DocumentSnapshot documentSnapshot = snapshot.data.documents[index].data();

You should use the following:
orderBy("timestamp", descending : true)
https://github.com/FirebaseExtended/flutterfire/blob/f5a408f0aed529da5602d4562964d60ff50d2a7e/packages/cloud_firestore/cloud_firestore/lib/src/query.dart#L224