Check If the user have the according field from DocumentSnapshot FirebaseFirestore, Flutter-CodePudding

I am trying to check ! If the user has the according field or not

like this example is "groupId"

If not I want it to show Text('no data');
If has I want it to show a Elevated button.
But the problem is. That whether it has the data or not it's still show the Elevated Button.
so how can I fix that?

here's the code

class _HalfScreenState extends State<HalfScreen> {
    final groupId = FirebaseAuth.instance.currentUser!.uid;

    @override
   Widget build(BuildContext context) {
     return StreamBuilder<DocumentSnapshot?>(
       stream: FirebaseFirestore.instance
         .collection("users")
        .doc(groupId)
        .snapshots(),
       ///The problem is HERE
    builder: (context, snapshot) {
      if (snapshot.data?.get("groupId") == true) {
        return const Text('no data');
      }
      return Column(
        children: [
          ElevatedButton(
            child: Text(
              (snapshot.data as DocumentSnapshot)['groupId'],
              style: const TextStyle(
                fontWeight: FontWeight.normal,
              ),
            ),
            onPressed: () => Navigator.pushAndRemoveUntil(
                context,
                PageTransition(
                    type: PageTransitionType.rightToLeft,
                    child: const GroupScreen()),
                (route) => false),
            style: ElevatedButton.styleFrom(
              primary: Colors.grey,
              onPrimary: Colors.black,
              elevation: 0.0,
              shape: const RoundedRectangleBorder(
                borderRadius: BorderRadius.zero,
              ),
            ),
          ),
        ],
      );
    });
     }
   }

I've been solving it for 4hours now but this is by far I've got. So if you guys know plz considered helping. 1: https://i.stack.imgur.com/tUkzg.png

CodePudding user response：

Try this:

builder: (context, snapshot) {
      return Column(
        children: [
          (snapshot.data!.data() as Map<String, dynamic>)['groupId'] == "" 
          ? Text('no data');
          : ElevatedButton(
            child: Text(
              (snapshot.data!.data() as DocumentSnapshot)['groupId'],
              style: const TextStyle(
                fontWeight: FontWeight.normal,
              ),
            ),
            onPressed: () => Navigator.pushAndRemoveUntil(
                context,
                PageTransition(
                    type: PageTransitionType.rightToLeft,
                    child: const GroupScreen()),
                (route) => false),
            style: ElevatedButton.styleFrom(
              primary: Colors.grey,
              onPrimary: Colors.black,
              elevation: 0.0,
              shape: const RoundedRectangleBorder(
                borderRadius: BorderRadius.zero,
              ),
            ),
          ),
        ],
      );
    }

CodePudding user response：

I feel there are two things mixed up, you are probably misusing group-id and user-id for the same thing.

You are assigning the user-id as group-id:

final groupId = FirebaseAuth.instance.currentUser!.uid

Then, you search for a user by said group-id:

FirebaseFirestore.instance.collection("users").doc(groupId)

Finally, you are trying to access the groupId-field of the user you found:

snapshot.data?.get("groupId") == true

Try something like this

final userId = FirebaseAuth.instance.currentUser!.uid`

// ...

FirebaseFirestore.instance.collection("users").doc(userId)

// ...

(snapshot.data()?.containsKey('groupId')
  && snapshot.data()?['groupId'] != "" 
          ? Text('no data');
          : ElevatedButton( ... )