Get Map<String, dynamic> from Map<dynamic, dynamic> flutter

Question

I have the code below :

 Map<dynamic, dynamic> result = snapshot.value;
 Map<String, dynamic> data = Map<String, dynamic>();
 for (dynamic type in result.keys) {
    data[type.toString()] = result[type];
 }
 print(data);
 print(data.runtimeType);

but data type is _InternalLinkedHashMap<String, dynamic> and i am not able to read its value, despite the ugly hack i have done above.

The direct cast also doesn't work : snapshot.value as Map<String, dynamic> throws the error : '_InternalLinkedHashMap<Object?, Object?>' is not a subtype of type 'Map<String, dynamic>'

I need to have a Map<String, dynamic> type to be able to create my custom class Object.

snapshot.value has a type of dynamic, but it's a json object that returns the result of a Realtime Database query and there is no documentation about how to retrieve the value into a Flutter object.

I have tried this answer but i can't use it as jsonDecode() takes a String as a parameter.

Answer 1

When I tried Tom's answer I got:

The argument type 'Object?' can't be assigned to the parameter type 'Map<dynamic, dynamic>'

To solve this, I had to do:

Map<String, dynamic>.from(snapshot.value as Map);

In fact, since all values in my database node are booleans, I was able to do this:

Map<String, bool>.from(snapshot.value as Map);

Answer 2

This recent Firecast video solved my problem at 27min.

I also had an non explicit Flutter error about another nested HashMap in my data model object that could not be converted directly.

The solution is to use Map<String, dynamic>.from(snapshot.value) and this for every nested Map you have in your data model object

EDIT : See Frank's answer below that is the correct one for the latest version of the firebase_database package.