How to set home page async and conditional?

user_14314892 0
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my app has a login page and logs in the user with an access token. At the start of the app, if user still has a token(which means did not logged out since last login), home page is X but if user does not have token home page is login page. There was no problem since I was using SharedPreferences to store the token but I decided to use flutter_secure_storage package. It's functions work async. So the problem is, after I changed SharedPreferences to flutter_secure_storage, if user does not have token and starts the app, page X is showing for a couple of seconds and then login page is coming. I used async/await functions for all flutter_secure_storage variables but can not use it for home page. I assumed it is because I can not make the app await for token check, it starts building page X and then realizes token is null and then builds login page.That may not be true, just my thought. My code for home: is

home: Constants.storage.read(key: "token") !=
                null 
            ? ChangeNotifierProvider(
                create: (context) => BooksPageViewModel(),
                child: BooksView(),
              )
            : ChangeNotifierProvider(
                create: (context) => LoginPageViewModel(),
                child: LoginPage(),
              ));

I tried to make a Future function but can't assigned it to home: ... I tried to make home: ... async but didn't happened. How can I set my home page to await for token check? Thanks in advance.

dart flutter
2 Answers

So if I understand correct the .storage.read function is async and has to be awaited in order for the token to not be null. In this case I would either use a Futurebuilder, or you execute the Constants.storage.read function beforehand like :

var token = await Constants.storage.read(key: "token");

if you run into the problem that you have to make your main method async, that's alright just call WidgetsFlutterBinding.ensureInitialized(); at the beginning of your main and it will work.

user_103681470

I turned my main to

Future main() async {

and as @MaxTromp said, I added WidgetsFlutterBinding.ensureInitialized(); Then I added a static String for my token to Constants and called the Constants.token = await Constants.storage.read(key: "token"); inside main. Then my home: is

home: Constants.token !=
                null 
            ? ChangeNotifierProvider(
                create: (context) => BooksPageViewModel(),
                child: BooksView(),
              )
            : ChangeNotifierProvider(
                create: (context) => LoginPageViewModel(),
                child: LoginPage(),
              ));

and now, it works perfectly.

user_143148920
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