How to retrieve one field data from a document in firebase flutter?

farahizzaty
April 20, 2023
286 views
1 vote
2 Answers

I want to print a data from patient information inside the user data collection with a current user id. I have successfully printed the result out but I don’t know how to pass it to my widget. I cannot use list view because I want to print just one field.

my firebase

This is the async function that I have made

retrieveSubCol() async {
     String fullName = '';
     await FirebaseFirestore.instance.collection('userData').get().then((value) {
      value.docs.forEach((result) {
        FirebaseFirestore.instance
            .collection('userData')
            .doc(result.id)
            .collection('patient_information')
            .get()
            .then((user) {
          user.docs.forEach((element) {
            print(element.data());
            fullName = element.data()['name'];
          });
        });
      });
    });
   }

This is my widget and future builder, I want to print the full Name in the Ali text:

Widget build(BuildContext context) {
       return FutureBuilder(
        future: retrieveSubCol(),
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.done) {
            return Scaffold(
              body: SingleChildScrollView(
                padding: EdgeInsets.only(top: 30),
                child: Container(
                  padding: const EdgeInsets.all(10),
                  child: Column(
                    children: [
                      Text(
                        "Profile",
                        style: TextStyle(
                          fontSize: 35,
                          fontWeight: FontWeight.w500,
                        ),
                      ),
                      SizedBox(
                        width: 120,
                        height: 120,
                        child: ClipRRect(
                            borderRadius: BorderRadius.circular(100),
                            child: Image(
                              image: AssetImage('images/doctor1.jpg'),
                            )),
                      ),
                      const SizedBox(height: 10),
                      Text('Ali',
                          style: Theme.of(context).textTheme.headlineMedium),
                      Text('About',
                          style: Theme.of(context).textTheme.bodyMedium),
                      const SizedBox(height: 20),
                      SizedBox(
                        child: ElevatedButton(
                          onPressed: () {},
                          child: const Text(
                            'Edit Profile',
                            style: TextStyle(
                                color: Color.fromARGB(255, 255, 255, 255)),
                          ),
                        ),
                      ),

I have tried to use return but still not work. Or maybe is there something wrong with my future builder?

My field in the patient_information subcollection:

Answers

Chosen as BEST ANSWER

Finally! I have found an answer!

This is the future function, before that I declared all the variables as String:

  Future retrieveSubCol() async {
    await FirebaseFirestore.instance.collection('userData').get().then((value) {
      value.docs.forEach((result) {
        FirebaseFirestore.instance
            .collection('userData')
            .doc(FirebaseAuth.instance.currentUser!.uid)
            .collection('patient_information')
            .get()
            .then((user) {
          user.docs.forEach((element) {
            print(element.data());
            setState(() {
              fullname = element.data()['name'];
              icNo = element.data()['icNo'];
              age = element.data()['age'];
              birthDate = element.data()['birthDate'];
              email = element.data()['email'];
              noPhone = element.data()['phoneNo'];
              address = element.data()['address'];
              history = element.data()['medicalHistory'];
              insurance = element.data()['medicalInsurance'];
              panel = element.data()['panelClinic'];
            });
          });
        });
      });
    });
  }

I declared it in inistate since I used setState:

void initState() {
 super.initState();
 retrieveSubCol();
}

Then I used StreamBuilder:


return StreamBuilder(
        stream: FirebaseAuth.instance.authStateChanges(),
        builder: (context, snapshot) {
          if (snapshot.hasData) {
            return Scaffold(
              body: SingleChildScrollView(
                padding: EdgeInsets.only(top: 30),
                child: Container(
                  padding: const EdgeInsets.all(10),
                  child: Column(
                    children: [
                      Text(
                        "Profile",
                        style: TextStyle(
                          fontSize: 35,
                          fontWeight: FontWeight.w500,
                        ),
                      ),
                      SizedBox(
                        width: 120,
                        height: 120,
                        child: ClipRRect(
                            borderRadius: BorderRadius.circular(100),
                            child: Image(
                              image: AssetImage('images/doctor1.jpg'),
                            )),
                      ),
                      const SizedBox(height: 10),
                      Text(fullname!,
                          style: Theme.of(context).textTheme.bodyMedium),
                      Text('About',
                          style: Theme.of(context).textTheme.bodyMedium),

All printed correctly according to my data!

(Edit)

If you want to display just the name field from the first document in the patient_information subcollection, you can do:

Widget build(BuildContext context) {
 return FutureBuilder(
  future: retrieveSubCol(),
  builder: (context, snapshot) {
    if (snapshot.connectionState == ConnectionState.done) {
      var querySnapshot = snapshot.data!; //⒈ Get the data
      var docs = querySnapshot.docs;      //⒉ Get the documents
      var firstDoc = docs[0];             //⒊ Get the first document
      var name = firstDoc.get("name");    //⒋ Get the name field from it
      return Text("Name: $name")          //⒌ Render it as a Text widget
    }
  }

Documentation is inline in the code above.

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