CODEWITHSUNDEEP
androidflutterfirebase-realtime-database
Taki
Taki

Reputation: 3730

getting null from realtime database in flutter

I'm creating a chat app in flutter using firebase , but i'm facing issues with getting data from realtime database , it is public chat , i'm not sure what is wrong that the data is not fetched , if anyone could help , i ll deeply appreciate it , thank you

enter image description here


Stream<Event> getMessages() {
   DatabaseReference databaseReference = FirebaseDatabase(databaseURL: databaseUrl).reference().child('Messages');
   return  databaseReference.onValue;
 }



Expanded(child: Container(
        child: StreamBuilder<Event>(
          stream: AuthService().getMessages(),
          builder: (context,data){
            if(data.hasError){
              return Center(
                child: Text("No data 1"),
              );
            }
            if(data.connectionState == ConnectionState.done){
              if(data.data!.snapshot.exists){
                print("data is in done" );
                Map<String,dynamic> values = data.data!.snapshot.value;
                for(var child in values.values){
                  var receiverName = child['userName'];
                  var receiverMessage = child['message'];
                  var receiverImageUrl = child['imageUrl'];
                  return Container(
                    child: Container(
                      child: Row(
                        children: [
                          Padding(
                            padding: const EdgeInsets.all(8.0),
                            child: CircleAvatar(
                              radius: 30,
                              backgroundColor: Colors.transparent,
                              backgroundImage: NetworkImage(receiverImageUrl),
                            ),
                          ),
                          Expanded(
                            child: Column(
                              children: [
                                Text(receiverName),
                                Text(receiverMessage)
                              ],
                            ),
                          )
                        ],
                      ),
                    ),
                  );
                }
              }
            }
            return Center(
              child: Text("No data 2"),
            );
          },
        ),
      )),

Upvotes: 0

Views: 426

Answers (1)

Frank van Puffelen
Frank van Puffelen

Reputation: 598807

Two problems in your code.

First up you're reading the entire database, only to use the Messages node. I recommend updating that to:

Stream<Event?> getMessages() {
  DatabaseReference databaseReference = FirebaseDatabase(databaseURL: databaseUrl).reference().child('Messages');
  return  databaseReference.onValue;
}

Second, since you're reading Messages your data.data!.snapshot will have multiple messages. So calls like data.data!.snapshot.value['userName'] won't work, because you don't say what message to read the userName from.

You'll want to loop through data.data!.snapshot.value.values to then get ['userName'] on the specific child snapshot it.

Upvotes: 2

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