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GitHub Clone & Push Changes git clone <repository-url> git push origin <branch-name> Git Pull Request (PR) & Code Review Resolve PR Merge Conflicts Change Default Branch & Repo Settings এই ভিডিওতে GitHub repository-এর default branch পরিবর্তন, visibility (public/private) change এবং repo delete করার option দেখানো হয়েছে। ...

Create Issue, Fix with PR & Delete Branch Add Collaborator / Give Repo Access How to Fork a GitHub Repository Checkout Remote Branch Locally Learn how to fetch remote branches and check them out locally for development. ...

Flutter == vs Value Equality code import 'package:equatable/equatable.dart'; class Contact extends Equatable { const Contact({required this.type, required this.value}); final String type; final String value; @override List<Object?> get props => [type, value]; } class Phone with Equatable { const Phone({this.isPrimary = false, this.contact}); final bool isPrimary; final Contact? contact; @override List<Object?> get props => [...contact?.props ?? [], isPrimary]; } void main() { Contact a = Contact(type: "phone", value: "0101"); Contact b = Contact(type: "phone", value: "0101"); if (a == b) { print("same same ...."); } else { print("a: ${a.toString()}"); print("b: ${b.toString()}"); } } equatable on pub.dev↗

user.dart import 'package:example/models/contact.dart'; import 'package:json_annotation/json_annotation.dart'; part 'user.g.dart'; // the `user` is the fileName @JsonEnum(valueField: "value") enum Gender { male("m"), female("f"); const Gender(this.value); final String value; } @JsonSerializable(fieldRename: FieldRename.screamingSnake) class User { User({ required this.name, required this.dateOfBirth, required this.gender, required this.contact, required this.presentAddress, }); final String name; final Gender gender; @JsonKey(name: "dob") final DateTime? dateOfBirth; final Contact contact; final String presentAddress; factory User.fromJson(Map<String, dynamic> json) => _$UserFromJson(json); Map<String, dynamic> toJson() => _$UserToJson(this); } Custom Converter class DateTimeConverter implements JsonConverter<DateTime?, Map<String, dynamic>?> { const DateTimeConverter(); @override DateTime? fromJson(Map<String, dynamic>? json) { if (json == null) return null; final second = json["seconds"]; return DateTime.fromMillisecondsSinceEpoch(second); } @override Map<String, dynamic>? toJson(DateTime? object) { if (object == null) return null; return {'seconds': (object.millisecondsSinceEpoch / 1000).round()}; } } Custom config build.yaml targets: $default: builders: json_serializable: options: # Options configure how source code is generated for every # `@JsonSerializable`-annotated class in the package. # # The default value for each is listed. any_map: false checked: false constructor: "" create_factory: true create_field_map: false create_json_keys: false create_json_schema: true create_per_field_to_json: false create_to_json: true date_time_utc: true disallow_unrecognized_keys: false explicit_to_json: false field_rename: snake generic_argument_factories: false ignore_unannotated: false include_if_null: true json_serializable on pub.dev↗

Flutter Freezed | Models, copyWith, JSON Serialization, Generics & Union Types Make sure to watch json_seriliazble first. Freezed class address.dart { "success": true, "data": { "street": "123 Main Street", "district": "Dhaka", "country": "Bangladesh" }, "message": "Address fetched" } import 'package:freezed_annotation/freezed_annotation.dart'; part 'address.freezed.dart'; part 'address.g.dart'; @freezed abstract class Address with _$Address { const factory Address({ required String street, required String district, required String country, }) = _Address; factory Address.fromJson(Map<String, Object?> json) => _$AddressFromJson(json); static const Address present = Address( street: "present", district: "addr.dis", country: "BD", ); static const Address permanent = Address( street: "permanent", district: "addr.dis", country: "...", ); } person.dart { "success": true, "data": { "name": "John Doe", "age": 25, "address": "Earth", "skills": ["Dart", "Flutter"], "presentAddress": { "street": "123 Main Street", "district": "Dhaka", "country": "Bangladesh" }, "permanentAddress": { "street": "45 Lake Road", "district": "Chattogram", "country": "Bangladesh" } }, "message": "Person fetched" } import 'package:freezed_annotation/freezed_annotation.dart'; import 'address.dart'; part 'user.freezed.dart'; part 'user.g.dart'; @freezed abstract class Person with _$Person { const factory Person({ required String name, int? age, @Default("Eath") String? address, @Default([]) List<String> skills, required Address presentAddress, Address? permanentAddress, }) = _Person; factory Person.fromJson(Map<String, Object?> json) => _$PersonFromJson(json); static const Person ui = Person( name: "0", age: 0, skills: [], presentAddress: Address.present, permanentAddress: Address.permanent, ); } Generic api_response.dart import 'package:freezed_annotation/freezed_annotation.dart'; part 'api_response.freezed.dart'; part 'api_response.g.dart'; @Freezed(genericArgumentFactories: true) abstract class ApiResponse<T> with _$ApiResponse<T> { const factory ApiResponse({ required bool success, T? data, String? message, }) = _ApiResponse<T>; factory ApiResponse.fromJson( Map<String, dynamic> json, T Function(Object?) fromJsonT, ) => _$ApiResponseFromJson(json, fromJsonT); } Union code-snippet We are using type instead of runtimetype ...

Who Owns the State? Callbacks & typedef Parent ↔ Child Communication code snippet import 'dart:math'; import 'package:flutter/material.dart'; void main() { runApp(const MyApp()); } class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) { return MaterialApp( theme: ThemeData(colorScheme: .fromSeed(seedColor: Colors.deepPurple)), home: const MyHomePage(), ); } } class MyHomePage extends StatefulWidget { const MyHomePage({super.key}); @override State<MyHomePage> createState() => _MyHomePageState(); } class _MyHomePageState extends State<MyHomePage> { int _counter = 0; @override Widget build(BuildContext context) { return Scaffold( body: Column( crossAxisAlignment: .stretch, children: [ SectionView( onTap: (v) async { _counter = v; setState(() {}); return "Something went wrong"; }, ), Text( _counter.toString(), style: TextStyle(fontSize: 55), textAlign: .center, ), SectionView( increment: false, onTap: (n) async { _counter = n; await Future.delayed(Duration(seconds: 2)); setState(() {}); return ""; }, ), ], ), ); } } typedef OnSectionViewChange = Future<String> Function(int); class SectionView extends StatefulWidget { const SectionView({super.key, this.increment = true, required this.onTap}); final bool increment; final OnSectionViewChange onTap; @override State<SectionView> createState() => _SectionViewState(); } class _SectionViewState extends State<SectionView> { bool isLoading = false; String errMsg = ""; Future<void> onTap() async { isLoading = true; setState(() {}); Random random = Random(); final number = random.nextInt(4444); errMsg = await widget.onTap(widget.increment ? number : number * -1); isLoading = false; setState(() {}); } @override Widget build(BuildContext context) { return Expanded( child: Material( color: widget.increment ? Colors.blueAccent : Colors.redAccent, child: Center( child: Column( mainAxisSize: .min, children: [ Text(errMsg), InkWell( onTap: isLoading ? null : onTap, child: isLoading ? Center(child: CircularProgressIndicator()) : Icon( widget.increment ? Icons.add : Icons.remove, size: 55, ), ), ], ), ), ), ); } } Why AlertDialog/BottomSheet UI doesn’t update even with setState Widget state 03 ...

FutureBuilder Learn Async Data & avoid common mistakes. future codeSnippet import 'dart:math'; import 'package:flutter/material.dart'; void main() => runApp( const MaterialApp(debugShowCheckedModeBanner: false, home: MyHomePage()), ); class MyHomePage extends StatefulWidget { const MyHomePage({super.key}); @override State<MyHomePage> createState() => _MyHomePageState(); } class _MyHomePageState extends State<MyHomePage> { //... Future<int> fetchData() async { await Future.delayed(Duration(seconds: 4)); final number = Random().nextInt(100); return number; } late Future<int> future = fetchData(); @override Widget build(BuildContext context) { return Scaffold( body: Center( child: FutureBuilder<int>( future: future, initialData: 100, builder: (context, AsyncSnapshot snapshot) { if (snapshot.hasError) { return Text(snapshot.error?.toString() ?? ""); } return Column( mainAxisSize: .min, children: [ if (snapshot.connectionState == ConnectionState.waiting) CircularProgressIndicator(), Text(snapshot.data.toString()), ], ); }, ), ), ); } } StreamBuilder Flutter’s Stream and StreamBuilder in detail. It also shows StreamController, StreamSubscription, stream error handling, single-subscription issue and event management with practical examples. ...

Learn Flutter’s Navigator API with practical examples of push, pop, pushReplacement, pushAndRemoveUntil, popUntil, canPop, and passing data between routes. main.dart import 'package:flutter/cupertino.dart'; import 'package:flutter/material.dart'; void main() { runApp( const MaterialApp(home: HomePage(), debugShowCheckedModeBanner: false), ); } class HomePage extends StatelessWidget { const HomePage({super.key}); @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: const Text("Home")), body: Center( child: ElevatedButton( onPressed: () async { final route = DetailsPage.route(); final result = await Navigator.push(context, route); print(result); }, child: const Text("Go to Details"), ), ), ); } } class DetailsPage extends StatelessWidget { const DetailsPage({super.key, required this.value}); final int value; static MaterialPageRoute route() => MaterialPageRoute( builder: (context) => DetailsPage(value: 123), settings: RouteSettings(arguments: 12312), ); @override Widget build(BuildContext context) { final canPop = ModalRoute.of(context)?.canPop ?? false; return Scaffold( appBar: AppBar(title: const Text("Details")), body: Center( child: Column( spacing: 16, mainAxisSize: .min, children: [ if (canPop) CloseButtonIcon(), ElevatedButton( onPressed: () { Navigator.of(context).pop("hello"); }, child: const Text("pop(result)"), ), ElevatedButton( onPressed: () { Navigator.of(context).pushReplacement(SettingsPage.route()); }, child: const Text("Settings with pushReplacement"), ), ElevatedButton( onPressed: () { Navigator.of(context).push(SettingsPage.route()); }, child: const Text("Settings with push"), ), ElevatedButton( onPressed: () { Navigator.of(context).pushAndRemoveUntil(SettingsPage.route(), ( route, ) { return false; }); }, child: const Text("pushAndRemoveUntil"), ), ], ), ), ); } } class SettingsPage extends StatelessWidget { const SettingsPage({super.key}); static MaterialPageRoute route() => MaterialPageRoute(builder: (_) => SettingsPage()); @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(title: const Text("Settings")), body: Center( child: Column( mainAxisSize: .min, children: [ ElevatedButton( onPressed: () { Navigator.of(context).popUntil((route) { return route.isFirst; }); }, child: const Text("popUntil(Home)"), ), ElevatedButton( onPressed: () { debugPrint("canPop: ${Navigator.canPop(context)}"); Navigator.maybePop(context); }, child: const Text("canPop / maybePop"), ), ], ), ), ); } }

Shared_preferences Persistent theme with Shared_preference. this is part of flutter_workshop provider shared_preferences on pub.dev↗