Question 120519 in Firebase Question posted in
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Firebase – Exception: type 'String' is not a subtype of type 'Map<dynamic, dynamic>' in type cast in flutter

When i creat a realtime database table then i get the table datas but i got an error: type ‘String’ is not a subtype of type ‘Map<dynamic, dynamic>’ in type cast

FirebaseAnimatedList(
        query: dbRef,
        itemBuilder: (BuildContext context, DataSnapshot snapshot,
          Animation<double> animation, int index) {
        Map data = snapshot.value as Map;
        data['key'] = snapshot.key;
        return listItem(data);
         },
      ),

I got Result

enter image description here

Tags:

3

Answers


  1. 0

    Here snapshot.data is a map and snapshot.value is string

    Try

    Map data = snapshot.data as Map;
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  2. 0

    You need to convert the dynamic value which comes in string into decoded jsonMap if it is a map using jsonDecode. Or, you can use snapshot.data which comes in terms of key, value pair Map.

    FirebaseAnimatedList(
        query: dbRef,
        itemBuilder: (BuildContext context, DataSnapshot snapshot,
          Animation<double> animation, int index) {
        Map data = jsonDecode(snapshot.value.toString());

// or
Map data = snapshot.data;


// Now do what you want to do
        data['key'] = snapshot.key;
        return listItem(data);
         },
      ),
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  3. 0

    I think your query returning single value,
    First test with it

    itemBuilder: (BuildContext context, DataSnapshot snapshot,
    Animation<double> animation, int index) {
  return Text("${snapshot.value}");
},

    Now for getting map, it is possible to get null value, for this case do

    itemBuilder: (BuildContext context, DataSnapshot snapshot,
    Animation<double> animation, int index) {
  Map? data = snapshot.value as Map?;
  final String? key = snapshot.key;
  return Text("Your ItemBUilder : $key ${data.toString()}");
},
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