Flutter-Dart Tips & Tricks - Part 1

1. Using isolates for concurrency:

   Dart's isolate system allows you to run multiple independent "isolated" threads of execution within a single Dart process. You can use isolates to perform CPU-intensive tasks without blocking the main UI thread, improving your app's responsiveness and performance.

   Example:

import 'dart:isolate';

void main() async {
  final receivePort = ReceivePort();
  final isolate = await Isolate.spawn(doHeavyWork, receivePort.sendPort);
  receivePort.listen((data) => print('Result: $data'));
}

void doHeavyWork(SendPort sendPort) {
  // Perform some CPU-intensive work here
  final result = 1 + 2 + 3 + 4 + 5;
  print('Result from Heavy Work: $result');
  sendPort.send(result);
}

1. Wait for the results of multiple Futures together:

   Returns a future that will complete once all the provided futures have completed, either with their results or with an error if any of the provided futures fail.

   Example:

class SomeAPI {
  Future<String> getThings() => Future.value('Hello');
  Future<int> getItems() => Future.value(300);
  Future<int> getStuff() => Future.value(30);
}

void main() async {
  final api = SomeAPI();
  final values = await Future.wait([
    api.getThings(),
    api.getItems(),
    api.getStuff(),
  ]);
  print('Here is the output: $values');
}

1. A more effective way to use 'Future.wait()' with asynchronous programming:

   In this example, we use closures (anonymous functions) to simplify asynchronous operations. The getUserData function uses the await keyword to wait for a fetchUserData function to complete and return a user object. Then, it returns the user's name.

   The getUserNames function takes a list of user IDs, maps them to getUserData functions using a closure, and uses Future.wait to wait for all the functions to complete. Finally, it maps the user data to their names and returns a list of names. This is a concise and readable way to handle asynchronous operations with multiple dependent calls.

Future<String> getUserData(int userId) async {
  final userData = await fetchUserData(userId);
  return userData.name;
}

Future<List<String>> getUserNames(List<int> userIds) async {
  final userFutures = userIds.map((id) => getUserData(id));
  final userData = await Future.wait(userFutures);
  return userData.map((data) => data.name).toList();
}

1. typedef for Functions:

   In Dart 1, If you want to utilize a function as a variable, field, or boundary, you have to make a typedef first.

   Example:

typedef EvenFilter = bool Function(int);

void main() {
  final list = [1, 2, 3, 4, 5];
  final evenFilter = (int n) => n % 2 == 0;
  final evenNumbers = list.where(evenFilter);
  print(evenNumbers);
}

1. typedef for Non-functions:

   With Dart 2.13, typedefs can be now used to create type aliases that refer to non-functions.

   Example:

typedef IntList = List<int>;

void main() {
  IntList data = [50, 60];
  data.add(100);
  print('length: ${data.length}');
  print('values: $data');
  print('type: ${data.runtimeType}');
}

// Output will be
length: 3
values: [50,60,100]
type: List<int>

And that's it for our first installment of Flutter tips and tricks! I hope you learned something new and useful that will help you build better and more efficient apps. 😎

Stay tuned for more articles in this series where I'll share more hidden gems and advanced techniques that will take your Flutter skills to the next level. 🐥

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