Flutter - StreamProvider - Sending reoccuring XHR Requests to Firebase - firebase

Question

I noticed my read requests increased significantly since I added a new Stream using StreamProvider, I managed to confirm this by removing the stream and no repeating requests where made. But I can't seem to track down why its repeating.
Note: The code functions fine, just these read requests have gone through the roof.
Stream
//get list of all open enquiries
Stream<List<EnquiryData>> get centreDashboardOpenEnquiries {
return centresCollection.document(centreID).collection('enquiries').where('enquiryStatus', whereIn: ['New', 'Contacted', 'Tour Scheduled', 'Tour Completed']).snapshots().map(_enquiryList);
}
//Map QuerySnapshot to List of EnquiryData
List<EnquiryData> _enquiryList(QuerySnapshot enquiry){
return enquiry.documents.map((doc) {
return EnquiryData(
enquiryID: doc.data['enquiryID'].toString(),
parentFirstName: doc.data['firstName'],
parentLastName: doc.data['lastName'],
parentPhoneNumber: doc.data['phoneNumber'],
parentEmail: doc.data['email'],
parentAddress: doc.data['address'],
methodOfEnquiry: doc.data['methodOfEnquiry'],
hearAboutUs: doc.data['hearAboutUs'],
specificHearAboutUs: doc.data['specificHearAboutUs'],
impressionOfCentre: doc.data['firstImpression'],
enquiryStatus: doc.data['enquiryStatus'],
created: doc.data['created'],
lastUpdated: doc.data['lastUpdated'],
);
}).toList();
}
Call Stream with CurrentOpenDataTable child
child: StreamProvider<List<EnquiryData>>.value(
value: EnquiryDatabaseService(centreID: widget.centreData.centreID).centreDashboardOpenEnquiries,
child: CurrentOpenDataTable(),
),
CurrentOpenDataTable()
class CurrentOpenDataTable extends StatefulWidget {
#override
_CurrentOpenDataTableState createState() => _CurrentOpenDataTableState();
}
class _CurrentOpenDataTableState extends State<CurrentOpenDataTable> {
#override
Widget build(BuildContext context) {
final enquiryData = Provider.of<List<EnquiryData>>(context) ?? [];
return DataTable(
showCheckboxColumn: false,
sortColumnIndex: 1,
sortAscending: true,
columns: [
DataColumn(
label: Text('Date'),
),
DataColumn(
label: Text('Name'),
//numeric: true,
),
DataColumn(
label: Text('Status'),
),
],
rows: _enquiryRow(context, enquiryData),
);
}
}
_dateFormat(DateTime dateTime) {
String formattedDate = DateFormat('dd/MM/yyyy').format(dateTime);
return formattedDate;
}
_enquiryRow(BuildContext context, List<EnquiryData> enquiryData) {
List<DataRow> listOfDataRows = List.generate(
enquiryData.length,
(index) => DataRow(
cells: [
DataCell(Text(_dateFormat(DateTime.fromMillisecondsSinceEpoch(
enquiryData[index].created)))),
DataCell(Text(enquiryData[index].parentFirstName +
' ' +
enquiryData[index].parentLastName)),
DataCell(Text(enquiryData[index].enquiryStatus)),
],
onSelectChanged: (bool selected) {
if (selected) {
showEnquiryDialog(context, enquiryData[index]);
}
}));
return listOfDataRows;
}

Answer 1

The widget (let's call it MyWidget) that contains the StreamProvider is constantly being rebuilt.
You shouldn't be creating the EnquiryDatabaseService inside StreamProvider<List<EnquiryData>>.value, instead, get the stream inside initState.
Example
class _MyWidgetState extends State<MyWidget> {
Stream<List<EnquiryData>> _stream;
#override
initState() {
_stream = EnquiryDatabaseService(centreID: widget.centreData.centreID). centreDashboardOpenEnquiries;
}
// ... in build
StreamProvider.value(
value: _stream,
child: Container(/* ... */),
),
}
Or don't use the .value constructor.
StreamProvider(
create: (_) => EnquiryDatabaseService(centreID: widget.centreData.centreID). centreDashboardOpenEnquiries,
child: Container(/* ... */),
),
Read more on the do's and don'ts here
More reference here - How to deal with unwanted widget build?