Flutter Future returns null - dart

Question

I've seen this already: https://stackoverflow.com/a/49146503/1757321
Followed the solution, but it is not working in my case.
Some enlightenment would do for me this afternoon
Future<String> loadInterest() async {
print('Going to load interests');
final whenDone = new Completer();
SharedPreferences prefs = await SharedPreferences.getInstance();
final token = await prefs.getString('token');
print('The token ${token}');
await this.api.interests(token).then((res) {
// print('The response: ${res['interests']}'); <-- this prints response alright. Data is coming.
whenDone.complete(res['interests']);
});
return whenDone.future;
}
Then I'm trying to use the above Future in a future builder like so:
new FutureBuilder(
future: loadInterest(),
builder: (BuildContext context, snapshot) {
return snapshot.connectionState == ConnectionState.done
? new Wrap(
children: InterestChips(snapshot.data),
)
: Center(child: CircularProgressIndicator());
},
),
Where InterestChips(...) is this:
InterestChips(items) {
print('Interest Chips ${items}');
List chipList;
for (Object item in items) {
chipList.add(Text('${item}'));
}
return chipList;
}
But, I always get null as the snapshot, which means the loadInterest() for the Future is not returning anything.
If I understand this answer correctly, then I'm doing mine along the lines of that: https://stackoverflow.com/a/49146503/1757321

Answer 1

You don't need to use a Completer for this. Since your method is already async, you should just do this for your first code block:
Future<String> loadInterest() async {
print('Going to load interests');
final whenDone = new Completer();
SharedPreferences prefs = await SharedPreferences.getInstance();
final token = await prefs.getString('token');
print('The token ${token}');
final res = await this.api.interests(token).then((res) {
// print('The response: ${res['interests']}'); <-- this prints response alright. Data is coming.
return res['interests']);
}
You might also want to check for snapshot.hasError to make sure you're not getting any exceptions in there.