Flutter Firebase Realtime Database.Streambuilder and listview.builder returns error Index out of range: index should be less - flutter

Question

i am using Flutter and Firebase to build an order app.I'm using Realtime Database and a streambuilder to fetch the data and every update and listview.builder to portray them.
When i display the data works fine but the problem is that when i am trying to expand the data in the RTDB i'm getting this error
Another exception was thrown: RangeError (index): Index out of range: index should be less than 22: 22.
I'm trying to expand the data on another page.Sorry if my question is a bit of a crap i am asking for the first time
Scaffold(
body: StreamBuilder(
stream: ref.onValue,
builder: (context, snapshot) {
if(
snapshot.hasData &&
snapshot.data != null &&
(snapshot.data! as DatabaseEvent).snapshot.children !=
null){
List<Orderlist> listorder = [];
final myorders = snapshot.data!.snapshot.children;
myorders.forEach((numoftable) {
count+=1;
String payment_state = '';
String payment_method = '';
List<Order> orders=[];
final number_of_orders = numoftable.children.length;
numoftable.children.forEach((order) {
if(order.key=='payment_state') payment_state=order.value.toString();
if(order.key=='payment_method') payment_method=order.value.toString();
List<Orderitem> orderitems = [];
final order_id = order.key.toString();
// print(order_id);
if(order_id.length<=3){
final node = order.value as Map<dynamic,dynamic>?;
String temp_pending='';
String temp_payment='';
String customer_uid='';
node!.forEach((keys,values) {
// orderitem.name = element;
if(keys!='description' && keys!='customer_uid'){
final value = values as Map<String,dynamic>;
String price='';
String description='';
String number_of_appereance='';
value.forEach((key, value) {
if(key=='price') price=value.toString();
if(key=='description') description=value;
if(key=='number of appereances') number_of_appereance = value.toString();
});
final orderitem = Orderitem(name: keys,price: price,description: description,number_of_appereance: number_of_appereance);
orderitems.add(orderitem);
}
if(keys=='description'){
temp_pending = values.toString();
}
if(keys=='customer_uid'){
customer_uid=values.toString();
}
},);
final nextorder = Order(number_of_table: int.tryParse(numoftable.key.toString()),
items: orderitems,order_ids: order_id,customer_uid: customer_uid,
pending: temp_pending,);
orders.add(nextorder);
}
});
final current_index = int.parse(numoftable.key.toString())-1;
`your text`
if(temp_length.isEmpty || count<=myorders.length){
temp_length.insert(current_index, orders.length);
}
else if(temp_length[current_index]<orders.length ){
temp_length[current_index]= orders.length;
ref.child(numoftable.key.toString()).update({'payment_state':'Not payed'});
ref.child(numoftable.key.toString()).update({'payment_method':'Cash'});
}
final nextorderlist = Orderlist(
orderlist: orders,
number_of_table: numoftable.key.toString(),
payment_state: payment_state,
payment_method: payment_method,
number_of_orders: number_of_orders);
// print(nextorder.order_ids);
listorder.add(nextorderlist);
// ref.child(numoftable.key.toString()).update({'check':'false'});
},
);
return Column(
children: [
GeneralSettings(),
Flexible(
child: GridView.builder(
shrinkWrap: true,
itemCount: listorder.length ,
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 3),
itemBuilder: (context, index) {
return _listoforders(listorder, index,);
},
),
),
],
);
}else if(snapshot.connectionState==ConnectionState.waiting){
Center(child: CircularProgressIndicator(),);
}
else if(snapshot.hasError){
return Text('Error');
}
return Text('Error');
}
),
);
}
Widget _listoforders(List<Orderlist> listoforders,int index) {
return GestureDetector(
onTap: (){
orders.clear();
listoforders[index].orderlist!.forEach((element) { orders.add(element); });
context.goNamed('Details');
},
child: Container(
color:listoforders[index].payment_state=='None' ? Colors.lightBlue : (listoforders[index].payment_state=='Not payed') ? Colors.red : Colors.green,
child: Column(
children: [
ListTile(title: Text(listoforders[index].number_of_table.toString()),
subtitle: listoforders[index].payment_state=='None' ? Icon(Icons.no_food) : listoforders[index].payment_state=='Not payed' ? Icon(Icons.money_off) : Text('Payed'),
trailing: IconButton(onPressed: () {
listoforders[index].orderlist!.forEach((element) {
setState(() {
temp_length[index]=0;
ref.child(listoforders[index].number_of_table.toString()).child(element.order_ids!).remove();
ref.child(listoforders[index].number_of_table.toString()).update({'payment_state':'None'});
ref.child(listoforders[index].number_of_table.toString()).update({'payment_method':'None'});
delete(element.customer_uid!);
});
});
}, icon: Icon(Icons.delete)),
leading: (listoforders[index].payment_method=='None' ) ? Text('No payment method') : (listoforders[index].payment_method=='With card' ) ? Icon(Icons.credit_card) : Icon(Icons.money_rounded),),
Flexible(
child: ListView.builder(
physics: ClampingScrollPhysics(),
shrinkWrap: true,
itemCount: listoforders[index].orderlist!.length,
itemBuilder: (context, current_index) {
final current_order = listoforders[index].orderlist![current_index];
return Container(
color: current_order.pending=='Unchecked' ? Colors.red : (current_order.pending=='pending') ? Colors.amber : Colors.green,
child: ListTile(
onTap: () => Navigator.push(context, MaterialPageRoute(builder: (context)=>OrderSettings(order: current_order))),
title: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(current_order.order_ids!),
],
),
subtitle: Text(current_order.pending!),
trailing: current_order.pending=='Unchecked' ? IconButton(onPressed: () => setState(() {
ref.child(current_order.number_of_table.toString()).child(current_order.order_ids!).update({"description":"pending"});
}) , icon: Icon(Icons.alarm_add)) :
current_order.pending=='pending' ? IconButton(onPressed: () => setState(() {
ref.child(current_order.number_of_table.toString()).child(current_order.order_ids!).update({"description":"Done"});
}) , icon: Icon(Icons.pending_actions)) : Icon(Icons.check),
leading: IconButton(onPressed:() {
ref.child(current_order.number_of_table.toString()).child(current_order.order_ids!).remove();
} ,
icon:Icon(Icons.delete) ,),
),
);
},),
),
],
),
),
);}
}
Future delete(String uid) async{
final doc = FirebaseFirestore.instance.collection('Customers').doc(uid);
await doc.update({'order':''});
}
I am updating the RTDB on this page
class UpdatePanel extends StatefulWidget {
String? name;
bool check;
int? tables;
UpdatePanel({super.key,this.name,required this.check, this.tables});
#override
State<UpdatePanel> createState() => _UpdatePanelState();
}
class _UpdatePanelState extends State<UpdatePanel> {
late DatabaseReference ref;
TextEditingController namecontroller = TextEditingController();
TextEditingController number_of_tables = TextEditingController();
#override
void initState() {
// TODO: implement initState
ref=FirebaseDatabase.instance.ref().child(widget.name!);
super.initState();
}
#override
Widget build(BuildContext context) {
print(widget.name);
print(widget.tables);
Size size = MediaQuery.of(context).size;
final futurefiles = FirebaseStorage.instance.ref().child('${widget.name}/');
return AlertDialog(
title: Text(widget.check? 'Update businness name':'Update tables number'),
content: Container(
height: size.height*0.3,
child: SingleChildScrollView(
child: Column(children: [
widget.check ?
Textwidget(controller: namecontroller, hinttext: 'Update name', labeltext: 'Name', icon: Icon(Icons.business_center), color: Colors.black) :
Textwidget(controller: number_of_tables, hinttext: 'Update number of tables', labeltext: 'Number of tables', icon: Icon(Icons.table_bar), color: Colors.black),
SizedBox(height: size.height*0.05,),
ElevatedButton.icon(onPressed: () {
setState(() {
DatabaseManager(displayName: widget.name).settabledata(int.parse(number_of_tables.text.trim()));
createQrcodes();
resetRTDB();
(context as Element).reassemble();
Navigator.pop(context);
});
}, icon: Icon(Icons.update), label: Text('Update'))
]),
),
),
actions: [
OutlinedButton(onPressed: () => Navigator.pop(context), child: Text('Close'))
],
);
}
void resetRTDB() async{
for(int i=widget.tables!+1;i<=int.parse(number_of_tables.text.trim());i++){
await ref.child('${i}').set({"payment_state":"None","payment_method":"None",});
}
}
Future<Uint8List> toQrImageData(String text) async {
try {
final image = await QrPainter(
data: text,
version: QrVersions.auto,
gapless: false,
color: Colors.black,
emptyColor: Colors.white,
).toImage(300);
final a = await image.toByteData(format: ImageByteFormat.png);
return a!.buffer.asUint8List();
} catch (e) {
throw e;
}
}
Future createQrcodes() async{
for(int i=widget.tables!+1;i<=int.parse(number_of_tables.text.trim());i++){
final path = '${widget.name!.trim()}/${i}';
final ref = FirebaseStorage.instance.ref().child(path);
final file = await toQrImageData(widget.name!.trim().toLowerCase()+' '+'${i}');
ref.putData(file,SettableMetadata(contentType: 'image/png'));
}
}
}

Answer 1

this is where your error occurs
void resetRTDB() async{
for(int i=widget.tables!+1;i<=int.parse(number_of_tables.text.trim());i++){
await ref.child('${i}').set({"payment_state":"None","payment_method":"None",});
}
after getting all the data and it tries to get new data by adding 1 in every time ,change try changing your logic here