Error: The await expression can only be used in an async function. Try marking the function body with either 'async' or 'async*'

Question

class Wrapper extends StatelessWidget {
  @override
  Widget build(BuildContext context) {

    final user = Provider.of<User>(context);
    DocumentSnapshot snapShot = await Firestore.instance.collection('members').document(user.uid).get(); //re

    //defining the user id
    List<String> hr = [
      "4xldjjaJKBOppV0ioZLaIekVNdr1",  //shreya [email protected]
      "20D18eFrsnRNmbtVnnvq8U0ZW1s2"   //pranav [email protected]
    ];
    List<String> doc = [
      "3DoGWLpamEVwXyT57hCyybkGIkc2",  //harsha [email protected]
      "YBHsJC5W6IYa1qfdIaXAwbvKKOG2",  //saampatii [email protected]
    ];
    List<String> gs = [
      "5QCDzv1YjQhQdLORJ7CthfATeHt1"   //digu [email protected]
    ];


    if(user == null){
      return Authenticate();
    }else if(snapShot == null || !snapShot.exists){return MemberData();}
    else{
      if(user.uid == hr[0]){return Hr();}
      else if(user.uid == hr[1]){return Hr();}
      else if(user.uid == doc[0]){return Doc();}
      else if(user.uid == doc[1]){return Doc();}
      else if(user.uid == gs[0]){return Gs();}
      else{return Home();}
    }
  }
}

What can I do to remove the error?

There I tried checking if the document with that uid is stored or not in my firestore. Is there any other way without getting an error?

Solution

To use await, you have to make your function async :

Future<Widget> getData(user) async {
  DocumentSnapshot snapShot = await Firestore.instance.collection('members')
                                                      .document(user.uid).get();
  //defining the user id
    List<String> hr = [
      "4xldjjaJKBOppV0ioZLaIekVNdr1",  //shreya [email protected]
      "20D18eFrsnRNmbtVnnvq8U0ZW1s2"   //pranav [email protected]
    ];
    List<String> doc = [
      "3DoGWLpamEVwXyT57hCyybkGIkc2",  //harsha [email protected]
      "YBHsJC5W6IYa1qfdIaXAwbvKKOG2",  //saampatii [email protected]
    ];
    List<String> gs = [
      "5QCDzv1YjQhQdLORJ7CthfATeHt1"   //digu [email protected]
    ];


    if(user == null){
      return Authenticate();
    }else if(snapShot == null || !snapShot.exists){return MemberData();}
    else{
      if(user.uid == hr[0]){return Hr();}
      else if(user.uid == hr[1]){return Hr();}
      else if(user.uid == doc[0]){return Doc();}
      else if(user.uid == doc[1]){return Doc();}
      else if(user.uid == gs[0]){return Gs();}
      return Home();
    }

}

Comments

[Samyak Jain]

Doing this another error occurred: This function has a return type of 'Widget', but doesn't end with a return statement. Try adding a return statement, or changing the return type to 'void'.

[fatalcoder524]

change Future to Future<Widget>. that shud fix. and return the output of that function call.

[Samyak Jain]

This is not working, can you suggest some other solution.

[Samyak Jain]

Error: This function has a return type of 'Widget', but doesn't end with a return statement. Try adding a return statement, or changing the return type to 'void'. Error: The value of the local variable 'user' isn't used. Try removing the variable, or using it. Error: The declaration 'getData' isn't referenced. Try removing the declaration of 'getData'.

[fatalcoder524]

Will modify the code.. changes:- in else part of code remove else and just return. That shud fix it.