Flutter await for try catch [duplicate] - flutter

Question

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How to Async/await in List.forEach() in Dart
(7 answers)
Closed 2 years ago.
I'm using firebase cloud firestore
inside a Future function I have this
try {
categories.forEach((element) async {
await FirebaseFirestore.instance.collection('Categories').add({
'name': element[0],
'imageUrl': element[1],
});
print('done');
});
print('complete');
} catch (e) {
CoolAlert.show(
context: context,
type: CoolAlertType.error,
content: Text(e),
text: "Upload Failed",
onConfirmBtnTap: () {
Navigator.pop(context);
Navigator.pop(context);
});
}
'completed' printed before 'done'
how to make it the opposite?
how to await for the forEach function to end first then proceed
and even if I moved print('complete'); after the whole try catch block it doesn't work either
so is there a way to wait try catch block?

Answer 1

You can use Future.foreach OR Future.doWhile
Future.doWhile :
int index = 0;
try {
Future.doWhile(() {
if (index < categories.length) {
await FirebaseFirestore.instance.collection('Categories').add({
'name': categories[index][0],
'imageUrl': categories[index][1],
});
print('done');
index++;
return true;
} else {
print('complete');
return false;
}
});
} catch (e) {
CoolAlert.show(
context: context,
type: CoolAlertType.error,
content: Text(e),
text: "Upload Failed",
onConfirmBtnTap: () {
Navigator.pop(context);
Navigator.pop(context);
});
}
Future.foreach:
try {
Future.forEach(categories,(element) async {
await FirebaseFirestore.instance.collection('Categories').add({
'name': element[0],
'imageUrl': element[1],
});
print('done');
});
print('complete');
} catch (e) {
CoolAlert.show(
context: context,
type: CoolAlertType.error,
content: Text(e),
text: "Upload Failed",
onConfirmBtnTap: () {
Navigator.pop(context);
Navigator.pop(context);
});
}