Code snippets

Abstract base class for use cases following Clean Architecture. Handles single input/output with Either for error handling.

import 'package:dartz/dartz.dart';

abstract class UseCase<Type, Params> {
  Future<Either<Failure, Type>> call(Params params);

Clean Architecture repository with abstract interface and implementation. Handles network/cache strategy.

// Domain layer – abstract
abstract class UserRepository {
  Future<Either<Failure, User>> getUser(String id);
  Future<Either<Failure, List<User>>> getUsers();

Complete Cubit pattern with states. Best practice for simple BLoC-lite state management.

import 'package:flutter_bloc/flutter_bloc.dart';

// States
sealed class CounterState {}

Production-ready GetX controller with reactive state, lifecycle hooks, and dependency injection.

import 'package:get/get.dart';

class ProductController extends GetxController {
  // Reactive state

Modern Riverpod 2.x AsyncNotifier pattern for async state management with codegen-ready syntax.

import 'package:riverpod_annotation/riverpod_annotation.dart';

part 'user_provider.g.dart';

Complete GoRouter configuration with nested routes, redirects, and route guards.

import 'package:go_router/go_router.dart';

final appRouter = GoRouter(
  initialLocation: '/',

Production-ready Dio HTTP client with interceptors, token refresh, and error handling.

import 'package:dio/dio.dart';

class ApiService {
  static const _baseUrl = 'https://api.example.com/v1';

Type-safe Firestore repository with CRUD, real-time streams, and pagination.

import 'package:cloud_firestore/cloud_firestore.dart';

class FirestoreRepository<T> {
  final CollectionReference collection;

Layout builder that adapts to screen size. Returns different widgets for mobile, tablet, and desktop.

enum ScreenSize { mobile, tablet, desktop }

extension ScreenSizeExtension on BuildContext {
  double get screenWidth => MediaQuery.of(this).size.width;

Reusable loading overlay widget that blocks interactions while async operations run.

class LoadingOverlay extends StatelessWidget {
  const LoadingOverlay({
    super.key,
    required this.isLoading,

Commonly needed String extension methods for Flutter apps — capitalization, truncation, validation, and more.

extension StringX on String {
  // Capitalize first letter
  String get capitalize => isEmpty ? this : '${this[0].toUpperCase()}${substring(1)}';

Useful DateTime extension methods for formatting, comparison, and humanizing timestamps in Flutter.

import 'package:intl/intl.dart';

extension DateTimeX on DateTime {
  // Formatting