unable to refresh state after forEach in flutter

Question

I want to refresh the state of my widget when the following forEach block gets over. But the problem is that before the for loop stops its execution my widget rebuilds it self i.e it doesn't wait for it to execute then refresh.

Code:-

publicQuicksDocuments.forEach((element) async{
  if(element.postIdList.isNotEmpty)
  {
    DocumentSnapshot doc=await postsReference.document(element.id).collection('userPosts').document(element.postIdList.last).get();
    element.postIdList.removeLast();
    postList.add(Post.fromDocument(doc));
  }
  else
  {
    publicPostsDocuments.remove(element);
  }
});           //After this for block overs then below code should execute and refresh the state
postList.shuffle();
setState(() {
  loading=false;
});

Please read the comment in the above code.

[Never use `Iterable.forEach` with an `async` callback](https://stackoverflow.com/a/63719805/). — jamesdlin, Dec 27 '20 at 07:13

score -1 · Answer 1 · answered Dec 27 '20 at 06:42

This should work,

//awaiting for the future to complete.
var variable=await publicQuicksDocuments.forEach((element) async{
  if(element.postIdList.isNotEmpty)
  {
    DocumentSnapshot doc=await postsReference.document(element.id).collection('userPosts').document(element.postIdList.last).get();
    element.postIdList.removeLast();
    postList.add(Post.fromDocument(doc));
  }
  else
  {
    publicPostsDocuments.remove(element);
  }
}); 
//After this for block overs then below code should execute and refresh the state
postList.shuffle();
setState(() {
  loading=false;
});

[Never use `Iterable.forEach` with an `async` callback](https://stackoverflow.com/a/63719805/). `Iterable.forEach` does not return anything; you cannot `await` it. — jamesdlin, Dec 27 '20 at 07:13

unable to refresh state after forEach in flutter

1 Answers1