How to read one field in a firestore sub collection using flutter?-CodePudding

In my code I tried to fecth age filed from users table using userID. Structure of database.

childPrivateDetails is a subcollection of user table

**I want to fetch age from this table how to do that and pass when click next button should pass the age to "void ageCa()" method **

code


class _GuideLineScreenState extends State<GuideLineScreen> {
  Future<void> getAge() async {
    final sp = context.read<SignInProvider>();
    Future<void> getAge() async {
      final path = 'users/${sp.uid}/childPrivateDetails/${sp.uid}';
      final reference = FirebaseFirestore.instance.doc(path);
      final age = await reference.get().then((value) => value.get('age'));
      print('age is: $age');
    }
  }

next button code

SizedBox(
                      width: 160.0,
                      height: 35.0,
                      child: ElevatedButton(
                        style: ButtonStyle(
                          shape:
                              MaterialStateProperty.all<RoundedRectangleBorder>(
                            RoundedRectangleBorder(
                              borderRadius: BorderRadius.circular(18.0),
                              side: const BorderSide(
                                color: Colors.blueAccent,
                              ),
                            ),
                          ),
                        ),
                        onPressed: () {
                          ageCa();
                        },
                        child: const Text(
                          'next',
                          style: TextStyle(
                            color: Colors.white,
                          ),
                        ),
                      ),
                    ),

void ageCa() code

void ageCa() {
    String age = age;
    final data = age.split(",");
    final List<int> numbers =
        data.map((e) => int.parse(e.replaceAll(RegExp('[^0-9]'), ''))).toList();

    //format "Years: 2, Months: 00, Days: 00"; only work on this format
    Duration ageDuration =
        Duration(days: numbers[0] * 365   numbers[1] * 30   numbers[2]);

    if (ageDuration >= const Duration(days: 2 * 288)) {
      Navigator.push(
        context,
        MaterialPageRoute(builder: (context) => const LoginScreen()),
      );
    } else {
      Navigator.push(
          context,
          MaterialPageRoute(
            builder: (context) => const HomeScreen(),
          ));
    }
  }

For this, I didn't use model path image

User ID in console

code

I added print($age); at the Widget build(BuildContext context) {

void ageCa()

CodePudding user response：

Try the following code:

FutureBuilder<DocumentSnapshot<Map<String, dynamic>>>(
  future: FirebaseFirestore.instance
        .collection("users")
        .doc(sp.uid)
        .collection("childPrivateDetails")
        .doc(sp.uid)
        .get(),
  builder: (context, snapshot) {
    if (snapshot.connectionState == ConnectionState.waiting) {
      return const CircularProgressIndicator();
    }

   return Text(snapshot.data.data()!["age"]);
  },
),

CodePudding user response：

Use the get() method to fetch single field like so:

Future<void> getAge() async {
    final uid = IZf3qxWtmxcWF6oXh1nbB8SK4az2
    final path = 'users/$uid/childPrivateDetails/$uid';
    final reference = FirebaseFirestore.instance.doc(path);
    final age = await reference.get().then((value) => value.get('age'));
    print('age is: $age');
  }

CodePudding user response：

As far as I know, firebase document snapshoot have just function .data() not an .data.data() Your error is highlighting that .data() not exists, and it is because .data before .data() is a function not a variable. I might be wrong, I'm not a swift programmer. Give me a call if I'm wrong and your snapshot returns something like variable .data.