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Flutter Firestore: How to convert future to Stream method for getting the realtime change data

I want to get the real-time change data when I update data. I have tried future method, but it only get one time.I want to convert future to stream method. I read the firebase document but I have not any ideas to do it. Can someone help me?

fromsnapshot

factory Medicine.fromSnapshot(DocumentSnapshot<Map<String, dynamic>> document){
    final data = document.data()!;
    return Medicine(
        id:data["id"],
        medicineName: data["name"],
        medicineType: data["type"],
        dosage: data["dosage"],
        startTime: data["startTime"],
        notice: data["notice"],
        image: data["image"],
        uid: data["userId"],
        status: data["status"],
        date: data["date"],
        desc: data["desc"],
        notiId: data["notiID"]

    );
  }

Here is the future method

Future<List<Medicine>> getAllMedRecord(String id) async {
    final snapshot = await _db.collection("ShareDate").doc(id).collection(
        "medicineReminder").get();
    final medicineData = snapshot.docs.map((e) => Medicine.fromSnapshot(e))
        .toList();
    return medicineData;
  }

future builder code

FutureBuilder<List<Medicine>>(
          future: controller.getAllMedRecord(currentUser!),
          builder: (context, snapshot) {
            if (snapshot.connectionState == ConnectionState.done) {
              if (snapshot.hasData) {
                return ListView.separated(
                  scrollDirection: Axis.vertical,
                  shrinkWrap: true,
                  separatorBuilder: (_, __) => const SizedBox(
                    height: 25,
                  ),
                  itemCount: snapshot.data!.length,
                  itemBuilder: (_, index) => GestureDetector(
                    onTap: () {
                      Medicine medicine = snapshot.data![index];
                      Get.to(() => MedicineDetailScreen(
                            medicine: medicine,
                          ));
                    },
                    child: Container(
                      height: snapshot.data![index].status! == "Pending"? 300 : 230,
                      decoration: BoxDecoration(
                        borderRadius: BorderRadius.circular(16),
                        color: tPrimaryColor,
                      ),
                      child: specialBackground(
                        top1: -140,
                        top2: 20,
                        height: 80,
                        child: Container(
                          padding: EdgeInsets.all(15),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              Text(
                                "Medicine Reminder",
                                style: Theme.of(context)
                                    .textTheme
                                    .headlineLarge!
                                    .apply(color: tDarkModeColor),
                                maxLines: 1,
                                overflow: TextOverflow.ellipsis,
                              ),
                              Text(
                                "Start Time: ${snapshot.data![index].startTime!}",
                                style: Theme.of(context)
                                    .textTheme
                                    .headlineMedium!
                                    .apply(
                                  color: tDarkModeColor,
                                ),
                              ),
                              Divider(color: tDarkModeColor,),
                              Row(
                                mainAxisAlignment: MainAxisAlignment.start,
                                children: [
                                  Image(
                                    image: NetworkImage(
                                        snapshot.data![index].image!),
                                    height: 90,
                                    width: 90,
                                  ),
                                  SizedBox(width: 30,),
                                  Column(
                                    crossAxisAlignment:
                                        CrossAxisAlignment.start,
                                    children: [
                                      Text(
                                        "Name: ${snapshot.data![index].medicineName!}",
                                        style: Theme.of(context)
                                            .textTheme
                                            .headlineMedium!
                                            .apply(color: tDarkModeColor),
                                        maxLines: 1,
                                        overflow: TextOverflow.ellipsis,
                                      ),
                                      Text(
                                        "Type: ${snapshot.data![index].medicineType!}",
                                        style: Theme.of(context)
                                            .textTheme
                                            .headlineMedium!
                                            .apply(
                                              color: tDarkModeColor,
                                            ),
                                        maxLines: 2,
                                        overflow: TextOverflow.ellipsis,
                                      ),
                                      Text(
                                          "Status: ${snapshot.data![index].status!}",
                                          style: Theme.of(context)
                                              .textTheme
                                              .headlineMedium!
                                              .apply(
                                                  color: snapshot.data![index].status! == "Took" ? Colors.green : snapshot.data![index].status! == "Pending"? Colors.grey : Colors.red )),
                                    ],
                                  ),
                                ],
                              ),
                              snapshot.data![index].status! == "Pending"?
                              Column(
                                children: [
                                  SizedBox(height: 20,),
                                  Row(
                                    children: [
                                      Expanded(
                                          child: ElevatedButton(
                                            style:
                                            ElevatedButton.styleFrom(backgroundColor: Colors.green),
                                            onPressed: () {
                                              controller.markStatusAsTook(snapshot.data![index].date!);
                                            },
                                            child: Text("Took".toUpperCase(),
                                                style: Theme.of(context)
                                                    .textTheme
                                                    .headlineMedium!
                                                    .apply(color: tWhiteColor)),
                                          )),
                                      SizedBox(
                                        width: 20,
                                      ),
                                      Expanded(
                                          child: ElevatedButton(
                                            style:
                                            ElevatedButton.styleFrom(backgroundColor: Colors.red),
                                            onPressed: () {
                                              controller.markStatusAsForget(snapshot.data![index].date!);
                                            },
                                            child: Text("Forgot".toUpperCase(),
                                                style: Theme.of(context)
                                                    .textTheme
                                                    .headlineMedium!
                                                    .apply(color: tWhiteColor)),
                                          ))
                                    ],
                                  ),
                                ],
                              )
                                  : Container()
                            ],
                          ),
                        ),
                      ),
                    ),
                  ),
                );
              } else if (snapshot.hasError) {
                return Center(child: Text(snapshot.error.toString()));
              } else {
                return const Center(child: Text('Something went wrong'));
              }
            } else {
              return Center(child: CircularProgressIndicator());
            }
          },
        ),

Get the real-time change data when I update data

Tags:

2

Answers


  1. 0

    In order to get real-time data from Firebase you need to change Future with Stream because Future will only call once and once the result is retrieved the Future Completes its promise.

    You can use this code :

    Stream<List<Medicine>> getAllMedRecord(String id) {
  return _db.collection("ShareDate").doc(id).collection("medicineReminder")
    .snapshots()
    .map((snapshot) => snapshot.docs.map((e) => Medicine.fromSnapshot(e)).toList());
}
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  2. 0

    I hope this helps

    class FirebaseFirestore extends StatefulWidget {
  const FirebaseFirestore({super.key});

  @override
  State<FirebaseFirestore> createState() => _FirebaseFirestoreState();
}

class _FirebaseFirestoreState extends State<FirebaseFirestore> {
  final _firestore = FirebaseFirestore.instance;
  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        StreamBuilder(
            stream: _firestore
                .collection('ShareDate')
                .orderBy('time', descending: true)
                .snapshots(),
            builder: (context, snapshot) {
              List<Widget> medicines = [];
              if (snapshot.hasData) {
                List<QueryDocumentSnapshot<Object?>>? meds =
                    snapshot.data?.docs;
                for (var medicine in meds) {
                  //get the data you need from the medicine
                  //for example
                  var date = medicine.data()['date'];
                  var name = medicine.data()['name'];
                  medicines.add(
                    Container(
                      child: Text('$date/$name'),
                    ),
                  );
                }
                return Expanded(child: ListView(
                  children: medicines,
                ),);
              }
            }),
      ],
    );
  }
}
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