Leveraging Promises for Flutter Application Development

In Dart, the concept of promises is implemented through a class called `Future`. A `Future` represents a computation that may not have completed yet. It can be used to handle asynchronous operations and obtain the result of the computation when it becomes available.

To create a promise in Dart, you typically use a function that returns a `Future`. For example, let’s say you have a function `fetchData()` that fetches some data asynchronously from a remote server. You can define it like this:

Future<String> fetchData() {
 // Simulating an asynchronous operation
 return Future.delayed(Duration(seconds: 2), () => 'Data fetched successfully');
}

In this example, `fetchData()` returns a `Future<String>`, indicating that it will eventually provide a `String` result.

You can then use this promise to handle the asynchronous computation. Here’s an example:

void main() {
 print('Fetching data…');
 
 fetchData().then((data) {
 print('Received data: $data');
 }).catchError((error) {
 print('Error occurred: $error');
 }).whenComplete(() {
 print('Data fetching completed.');
 });
}

In this example, the `then()` method is used to register a callback function that will be executed when the `fetchData()` operation completes successfully. The…