I'm new to flutter. I'm working on small projects which is like a scanning QR app. Here, I used hive to store scanned data in box but the problem is, it is storing duplicate values. I need to remove that duplicate data how to do it?
code:
class PageState extends State<PassthroughQrScanPage> {
final ApiRepository repository = ApiRepository(
apiClient: ApiClient(
httpClient: http.Client(),
),
);
@override
void initState() {
super.initState();
openBox();
Prefs().reload();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: BlocProvider(
create: (context) => PassthroughqrscanBloc(repository),
child: BlocConsumer<PassthroughqrscanBloc, PassthroughqrscanState>(
listener: (context, state) {
if (state is PassthroughqrscanEmpty) {
return scan(context);
}
if (state is PassthroughqrscanError) {
Navigator.pop(context);
ShowErrorMessage(context, state.error.message.toString());
}
if (state is PassthroughqrscanLoaded) {
List<Batch> cleared = [];
state.entity.batches.forEach((element) {
cleared.add(element);
});
// final clearedData =
// cleared.map((item) => jsonEncode(item)).toList();
// final uniqueJsonList = clearedData.toSet().toList();
// List result =
// uniqueJsonList.map((item) => jsonDecode(item)).toList();
var seen = Set<int>();
List<Batch> clearedData = cleared
.where((cleared) => seen.add(cleared.batchNumber!))
.toList();
// clearedData = [
// ...{...clearedData}
// ];
clearedData.forEach((element) {
debugPrint(
"check the values for all the sdasd ${element.batchNumber}");
box.add(Batch(
batchNumber: element.batchNumber,
isUsed: element.isUsed,
transactionId: element.transactionId));
});
print("adding ssssss ${box.values.toList()}");
// String json = jsonEncode(state.entity);
// print("------>>>>>>>>>>>D>S>D>>$json");
// Prefs().setPassthroughData(json);
Navigator.pop(context);
WidgetsBinding.instance.addPostFrameCallback((_) {
showDialog(
context: context,
builder: (ctxDialog) => PassDialog(
compoundCode: widget.compoundCode.toString(),
lotNo: widget.lotNo.toString(),
schedule_id: widget.schedule_id.toString(),
screenClosed: _screenWasClosed,
scheduleRange: widget.scheduleRange,
batchQty: widget.batchQty,
));
});
}
// return Container();
Center(
child: CircularProgressIndicator(),
);
},
builder: (context, state) {
if (state is PassthroughqrscanEmpty) {
return scan(context);
} else
return scan(context);
},
),
),
);
}
scan(BuildContext mcontext) =>
MobileScanner(
controller: MobileScannerController(facing: CameraFacing.back),
allowDuplicates: false,
onDetect: (barcode, args) {
if (barcode.rawValue == null) {
WidgetsBinding.instance.addPostFrameCallback((_) {
ScaffoldMessenger.of(context).showSnackBar(SnackBar(
content: Text("Scan correct QR"),
duration: Duration(milliseconds: 800)));
});
} else {
String code = barcode.rawValue ?? "";
debugPrint('Barcode found! $code');
if (code.isNotEmpty) {
// if (!_screenOpened) {
// _screenOpened = true;
passthroughData = jsonDecode(code);
passthroughQrScan =
PassthroughQrScanData.fromJson(passthroughData);
BlocProvider.of<PassthroughqrscanBloc>(mcontext)
..add(VerifyPassthroughBatch(
passthroughQrScan?.operationName ?? "",
widget.schedule_id.toString(),
passthroughQrScan?.transactionId ?? "",
passthroughQrScan?.transactionRange ?? ""));
buildShowDialog(context);
}
}
});
Widget ShowErrorMessage(BuildContext context, String error) {
print("------------------------------/./././$error");
WidgetsBinding.instance.addPostFrameCallback((_) {
ScaffoldMessenger.of(context).showSnackBar(SnackBar(
content: Text("Scan correct QR"),
duration: Duration(milliseconds: 800)));
});
return scan(context);
}
Future<void> openBox() async {
box = await Hive.openBox<Batch>("GetBatches");
// box = Boxes.getAllBatches();
await box.clear();
debugPrint("wwwwwwwwwwwwwwwwwkekekkkkkkkkk${box.values}");
// await box.deleteAll(box.keys);
}
}
List<Batch> batched = [];
var data;
class PassDialog extends StatefulWidget {
// const PassDialog({Key? key}) : super(key: key);
String? schedule_id;
String? compoundCode;
String? lotNo;
final Function() screenClosed;
final String? scheduleRange;
final int? batchQty;
PassDialog(
{required this.schedule_id,
required this.compoundCode,
required this.lotNo,
required this.screenClosed,
required this.scheduleRange,
required this.batchQty});
@override
State<PassDialog> createState() => _PassDialogState();
}
class _PassDialogState extends State<PassDialog> {
@override
void initState() {
batched = box.values.toSet().toList();
print("got values check for $batched");
super.initState();
}
@override
Widget build(BuildContext context) {
// List<Batch> batch = box.get("GetBatches");
//Batch batch = box?.get("GetBatches");
return SizedBox(
width: 150,
height: 100,
child: AlertDialog(
content: SingleChildScrollView(
child: Column(
children: [
// batched.forEach((element) {
for (final q in batched)
Text(
'${q.batchNumber.toString()}--${q.isUsed.toString()}--${q.transactionId.toString()}'),
// }),
Row(
children: [
ElevatedButton(
onPressed: () {
// print(values);
widget.screenClosed();
Navigator.of(
context,
rootNavigator: true,
).pop(
context,
);
},
child: Text("Continue")),
SizedBox(
width: 10,
),
ElevatedButton(
onPressed: () {
print(widget.scheduleRange);
WidgetsBinding.instance.addPostFrameCallback((_) {
Navigator.push(
context,
new MaterialPageRoute(
builder: (_) => GluePassthroughUploadPage(
id: widget.schedule_id.toString(),
compoundCode:
widget.compoundCode.toString(),
lotNo: widget.lotNo.toString(),
scheduleRange: widget.scheduleRange,
batchQty: widget.batchQty,
// getAllBatch: getBatch,
)));
});
},
child: Text("Show Add page")),
],
),
],
),
),
// Text("hohohoooooo${batched[0].batchNumber}${batched[0].isUsed}"),
),
);
}
}
Future buildShowDialog(BuildContext context) {
return showDialog(
context: context,
barrierDismissible: false,
builder: (BuildContext context) {
return Center(
child: CircularProgressIndicator(),
);
});
}
How to remove duplicate list of objects? I'm using Batch as model class. I tried many methods to solve this issue. toSet(), like that.......
CodePudding user response：
If you want dealing with more complex objects, store seen ids to the Set and filter away those ones that are already in the set.
final list = ['a', 'a', 'b', 'c', 'c'];
final seen = <String>{};
final uniqueList = list.where((str) => seen.add(str)).toList();
print(uniqueList); // => ['a', 'b', 'c']
CodePudding user response：
With the help of this, You can easily get Unique data from list and it will remove duplicate value
uniqueList = uniqueList.toSet().toList();
CodePudding user response：
For your Batch Model, you can filter with a function like this:
List<Batch> removeDuplicates(List<Batch> items) {
List<Batch> uniqueItems = []; // uniqueList
var uniqueIDs = items
.map((e) => e.uniqueID)
.toSet(); //list if UniqueID to remove duplicates
uniqueIDs.forEach((e) {
uniqueItems.add(items.firstWhere((i) => i.uniqueID == e));
}); // populate uniqueItems with equivalent original Batch items
return uniqueItems;//send back the unique items list
}
Replace uniqueID with the parameter you want to use for filtering duplicates