Лаб 6 (сделать bloc для страницы с описанием игры)

lib/components/utils/debounce.dart

@@ -0,0 +1,21 @@
+import 'dart:async';
+import 'dart:ui';
+
+class Debounce {
+  factory Debounce() => _instance;
+
+  Debounce._();
+
+  static final Debounce _instance = Debounce._();
+
+  static Timer? _timer;
+  // если в течении 0.5 сек появится новый вызов (изменится текст в поле ввода)
+  // то текущий вызов заменяется новым
+  static void run (
+      VoidCallback action, {
+        Duration delay = const Duration(milliseconds: 500),
+      }) {
+    _timer?.cancel();
+    _timer = Timer(delay, action);
+  }
+}

lib/data/dto/games_dto.dart

@@ -8,14 +8,18 @@ class GamesDto {
   @JsonKey(name: 'results')
   final List<GameDto>? data;
 
-  const GamesDto({this.data});
+  final int? current;
+  final int? next;
+  // final int? previous;
+
+  const GamesDto({this.data, this.current, this.next});
 
   factory GamesDto.fromJson(Map<String, dynamic> json) => _$GamesDtoFromJson(json);
 }
 
 @JsonSerializable(createToJson: false)
 class GameDto {
-  //для rawg, для получения описания игры
+  //для получения описания игры
   @JsonKey(name: 'id')
   final int? id;
 
@@ -27,7 +31,6 @@ class GameDto {
   @JsonKey(name: 'background_image')
   final String? image;
 
-  // @JsonKey(name: 'original_release_date')
   @JsonKey(name: 'released')
   final String? date;
 
@@ -35,20 +38,3 @@ class GameDto {
 
   factory GameDto.fromJson(Map<String, dynamic> json) => _$GameDtoFromJson(json);
 }
-
-@JsonSerializable(createToJson: false)
-class GameInfoDto extends GameDto{
-  GameInfoDto(super.id, super.name, super.description, super.image, super.date);
-
-}
-
-// giant bomb
-// @JsonSerializable(createToJson: false)
-// class ImageDto {
-//   @JsonKey(name: 'original_url')
-//   final String? originalUrl;
-//
-//   const ImageDto({this.originalUrl});
-//
-//   factory ImageDto.fromJson(Map<String, dynamic> json) => _$ImageDtoFromJson(json);
-// }

lib/data/dto/games_dto.g.dart

@@ -10,7 +10,22 @@ GamesDto _$GamesDtoFromJson(Map<String, dynamic> json) => GamesDto(
   data: (json['results'] as List<dynamic>?)
       ?.map((e) => GameDto.fromJson(e as Map<String, dynamic>))
       .toList(),
-    );
+  current: getNextPageNumber(json['next']) != null ? getNextPageNumber(json['next'])! - 1 : null,
+  next: getNextPageNumber(json['next']),
+);
+
+int? getNextPageNumber(String url) {
+  RegExp regExp = RegExp(r'page=(\d+)');
+  Match? match = regExp.firstMatch(url);
+  String? number;
+  if (match != null) {
+    return int.parse(match.group(1)!);
+  }
+  //по умолчанию след. = 2, т.е. тек. = 1
+  else {
+    return null;
+  }
+}
 
 GameDto _$GameDtoFromJson(Map<String, dynamic> json) => GameDto(
       (json['id'] as num?)?.toInt(),

lib/data/mappers/games_mapper.dart

@@ -1,18 +1,27 @@
 import 'package:mobiles_labs_5th_semester/data/dto/games_dto.dart';
 import 'package:mobiles_labs_5th_semester/domain/models/game.dart';
-import 'package:html/parser.dart';
+import 'package:mobiles_labs_5th_semester/domain/models/page_of_games_home.dart';
+
+extension GamesDtoToModel on GamesDto {
+  PageOfGames toDomain() => PageOfGames(
+      data: data?.map((e) => e.toDomain()).toList(),
+      nextPage: next);
+}
 
 extension GameDtoToModel on GameDto {
   GameData toDomain() {
-    // удаление HTML-тегов и системных символов из описания
+    // удаление HTML-тегов из описания
     String cleanedDescription = description ?? '';
     if (cleanedDescription.isNotEmpty) {
-
-      cleanedDescription = cleanedDescription.replaceAll(RegExp(r'<[^>]*>'), '');
-      //cleanedDescription = cleanedDescription.replaceAll(RegExp(r'\n|\r|\t'), ' ');
+      cleanedDescription =
+          cleanedDescription.replaceAll(RegExp(r'<[^>]*>'), '');
     }
     // return GameData(name: name ?? 'Неизвестная игра', price: 100, image: image?.originalUrl, description: cleanedDescription);
-    return GameData(id:id, name: name ?? 'Неизвестная игра', date: DateTime.parse(date ?? '2000-01-01'), image: image, description: cleanedDescription);
-
+    return GameData(
+        id: id,
+        name: name ?? 'Неизвестная игра',
+        date: DateTime.parse(date ?? '2000-01-01'),
+        image: image,
+        description: cleanedDescription);
   }
 }

lib/data/repositories/api_interface.dart

@@ -1,5 +1,8 @@
 import 'package:mobiles_labs_5th_semester/domain/models/game.dart';
+import 'package:mobiles_labs_5th_semester/domain/models/page_of_games_home.dart';
+
+typedef OnErrorCallback = void Function(String? error);
 
 abstract class ApiInterface {
-  Future<List<GameData>?> loadData(String? q);
+  Future<PageOfGames?> loadData({OnErrorCallback? onError});
 }

lib/data/repositories/games_repository.dart

@@ -5,6 +5,8 @@ import 'package:dio/dio.dart';
 import 'package:mobiles_labs_5th_semester/domain/models/game.dart';
 import 'package:pretty_dio_logger/pretty_dio_logger.dart';
 
+import '../../domain/models/page_of_games_home.dart';
+
 
 class GamesRepository extends ApiInterface {
   // Для обращения к api, с удобным выводом в консоль
@@ -14,28 +16,30 @@ class GamesRepository extends ApiInterface {
       requestBody: true,
     ));
 
-  // static const String _baseUrl = 'https://www.giantbomb.com';
   static const String _baseUrl = 'https://api.rawg.io';
 
 
   @override
-  Future<List<GameData>?> loadData(String? q) async {
+  Future<PageOfGames?> loadData({OnErrorCallback? onError, String? q, int page = 1, int pageSize = 10}) async {
     try {
-      // const String url = '$_baseUrl/api/games/?api_key=cfbca5bd0888309438b9cef29bbe13364bece292&format=json&limit=30&filter=date_added:2020-01-01|2099-12-31,original_release_date:2020-01-01|2099-12-31,platforms:94';
-      String url = '$_baseUrl/api/games?key=793f3ef5bdb64d128bebbb6e68ab89bd&format=json&page_size=10&platforms=4';
+      String url = '$_baseUrl/api/games?key=793f3ef5bdb64d128bebbb6e68ab89bd&format=json&platforms=4';
+      url += '&page=$page';
+      url += '&page_size=$pageSize';
+
       if (q != null) {
         url += '&search=$q';
       }
+
       final Response<dynamic> response = await _dio.get<Map<dynamic, dynamic>>(url);
 
       final GamesDto gamesDto = GamesDto.fromJson(response.data as Map<String, dynamic>);
 
-      final List<GameData>? data = gamesDto.data?.map((e) => e.toDomain()).toList();
+      final PageOfGames? data = gamesDto.toDomain();
 
       return data;
     }
     on DioException catch (e) {
-
+      onError?.call(e.error?.toString());
       return null;
     }
   }
@@ -52,7 +56,6 @@ class GamesRepository extends ApiInterface {
       return data;
     }
     on DioException catch (e) {
-
       return null;
     }
   }

lib/domain/models/page_of_games_home.dart

@@ -0,0 +1,8 @@
+import 'package:mobiles_labs_5th_semester/domain/models/game.dart';
+
+class PageOfGames {
+  final List<GameData>? data;
+  final int? nextPage;
+  //final int? prevPage;
+  PageOfGames({this.data, this.nextPage});
+}

lib/main.dart

@@ -1,4 +1,7 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:mobiles_labs_5th_semester/data/repositories/games_repository.dart';
+import 'package:mobiles_labs_5th_semester/presentation/home_page/bloc/bloc.dart';
 
 import 'presentation/home_page/home_page.dart';
 
@@ -14,7 +17,18 @@ class MyApp extends StatelessWidget {
     return MaterialApp(
       title: 'Flutter Demo',
       debugShowCheckedModeBanner: false,
-      home: const MyHomePage(title: 'Чернышев Георгий Янович'),
+      home: RepositoryProvider<GamesRepository>(
+        //репозиторий будет создан только тогда, когда будет запрошен, а не сразу при создании виджета
+        lazy: true,
+        create: (_) => GamesRepository(),
+        child: BlocProvider(
+          //bloc будет создан сразу при создании виджета
+          lazy: false,
+          //context нужен, чтобы суметь обратиться к провайдеру, кот. выше по дереву
+          create: (context) => HomeBloc(context.read<GamesRepository>()),
+          child: const HomePage(title: 'Чернышев Георгий Янович'),
+        ),
+      )
     );
   }
 }

lib/presentation/home_page/bloc/bloc.dart

@@ -0,0 +1,40 @@
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:mobiles_labs_5th_semester/data/repositories/games_repository.dart';
+import 'events.dart';
+import 'state.dart';
+
+class HomeBloc extends Bloc<HomeEvent, HomeState> {
+  final GamesRepository repo;
+
+  //связывание метода с конкретным событием в конструкторе
+  HomeBloc(this.repo) : super (const HomeState()) {
+    on<HomeLoadDataEvent>(_onLoadData);
+  }
+
+  //Emitter - генератор событий
+  Future<void> _onLoadData(HomeLoadDataEvent event, Emitter<HomeState> emit) async{
+    if (event.nextPage == null) {
+      emit(state.copyWith(isLoading: true));
+    } else {
+      emit(state.copyWith(isPaginationLoading: true));
+    }
+
+    String? error;
+
+    final data = await repo.loadData(
+      q: event.search,
+      page: event.nextPage ?? 1,
+      onError: (e) => error = e
+    );
+    if (event.nextPage != null) {
+      data?.data?.insertAll(0, state.data?.data ?? []);
+    }
+
+    emit(state.copyWith(
+        data: data,
+        isLoading: false,
+        isPaginationLoading: false,
+        error: error
+    ));
+  }
+}

lib/presentation/home_page/bloc/events.dart

@@ -0,0 +1,10 @@
+abstract class HomeEvent {
+  const HomeEvent();
+}
+
+class HomeLoadDataEvent extends HomeEvent {
+  final String? search;
+  final int? nextPage;
+
+  const HomeLoadDataEvent({this. search, this.nextPage});
+}

lib/presentation/home_page/bloc/state.dart

@@ -0,0 +1,24 @@
+import 'package:equatable/equatable.dart';
+import 'package:mobiles_labs_5th_semester/domain/models/game.dart';
+import 'package:mobiles_labs_5th_semester/domain/models/page_of_games_home.dart';
+import 'package:copy_with_extension/copy_with_extension.dart';
+
+part 'state.g.dart';
+
+@CopyWith()
+class HomeState extends Equatable {
+  final PageOfGames? data;
+  final bool isLoading;
+  final bool isPaginationLoading;
+  final String? error;
+
+  const HomeState(
+      {this.data,
+      this.isLoading = false,
+      this.isPaginationLoading = false,
+      this.error});
+
+  //какие поля будут сравниваться у состояний
+  @override
+  List<Object?> get props => [data, isLoading, isPaginationLoading, error];
+}

lib/presentation/home_page/bloc/state.g.dart

@@ -0,0 +1,92 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'state.dart';
+
+// **************************************************************************
+// CopyWithGenerator
+// **************************************************************************
+
+abstract class _$HomeStateCWProxy {
+  HomeState data(PageOfGames? data);
+
+  HomeState isLoading(bool isLoading);
+
+  HomeState isPaginationLoading(bool isPaginationLoading);
+
+  HomeState error(String? error);
+
+  /// This function **does support** nullification of nullable fields. All `null` values passed to `non-nullable` fields will be ignored. You can also use `HomeState(...).copyWith.fieldName(...)` to override fields one at a time with nullification support.
+  ///
+  /// Usage
+  /// ```dart
+  /// HomeState(...).copyWith(id: 12, name: "My name")
+  /// ````
+  HomeState call({
+    PageOfGames? data,
+    bool? isLoading,
+    bool? isPaginationLoading,
+    String? error,
+  });
+}
+
+/// Proxy class for `copyWith` functionality. This is a callable class and can be used as follows: `instanceOfHomeState.copyWith(...)`. Additionally contains functions for specific fields e.g. `instanceOfHomeState.copyWith.fieldName(...)`
+class _$HomeStateCWProxyImpl implements _$HomeStateCWProxy {
+  const _$HomeStateCWProxyImpl(this._value);
+
+  final HomeState _value;
+
+  @override
+  HomeState data(PageOfGames? data) => this(data: data);
+
+  @override
+  HomeState isLoading(bool isLoading) => this(isLoading: isLoading);
+
+  @override
+  HomeState isPaginationLoading(bool isPaginationLoading) =>
+      this(isPaginationLoading: isPaginationLoading);
+
+  @override
+  HomeState error(String? error) => this(error: error);
+
+  @override
+
+  /// This function **does support** nullification of nullable fields. All `null` values passed to `non-nullable` fields will be ignored. You can also use `HomeState(...).copyWith.fieldName(...)` to override fields one at a time with nullification support.
+  ///
+  /// Usage
+  /// ```dart
+  /// HomeState(...).copyWith(id: 12, name: "My name")
+  /// ````
+  HomeState call({
+    Object? data = const $CopyWithPlaceholder(),
+    Object? isLoading = const $CopyWithPlaceholder(),
+    Object? isPaginationLoading = const $CopyWithPlaceholder(),
+    Object? error = const $CopyWithPlaceholder(),
+  }) {
+    return HomeState(
+      data: data == const $CopyWithPlaceholder()
+          ? _value.data
+          // ignore: cast_nullable_to_non_nullable
+          : data as PageOfGames?,
+      isLoading: isLoading == const $CopyWithPlaceholder() || isLoading == null
+          ? _value.isLoading
+          // ignore: cast_nullable_to_non_nullable
+          : isLoading as bool,
+      isPaginationLoading:
+          isPaginationLoading == const $CopyWithPlaceholder() ||
+                  isPaginationLoading == null
+              ? _value.isPaginationLoading
+              // ignore: cast_nullable_to_non_nullable
+              : isPaginationLoading as bool,
+      error: error == const $CopyWithPlaceholder()
+          ? _value.error
+          // ignore: cast_nullable_to_non_nullable
+          : error as String?,
+    );
+  }
+}
+
+extension $HomeStateCopyWith on HomeState {
+  /// Returns a callable class that can be used as follows: `instanceOfHomeState.copyWith(...)` or like so:`instanceOfHomeState.copyWith.fieldName(...)`.
+  // ignore: library_private_types_in_public_api
+  _$HomeStateCWProxy get copyWith => _$HomeStateCWProxyImpl(this);
+}

lib/presentation/home_page/home_page.dart

@@ -1,23 +1,30 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/cupertino.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:mobiles_labs_5th_semester/data/repositories/mock_repository.dart';
 import 'package:mobiles_labs_5th_semester/domain/models/game.dart';
+import 'package:mobiles_labs_5th_semester/main.dart';
 import 'package:mobiles_labs_5th_semester/presentation/details_page/details_page.dart';
+import 'package:mobiles_labs_5th_semester/presentation/home_page/bloc/bloc.dart';
+import 'package:mobiles_labs_5th_semester/presentation/home_page/bloc/events.dart';
+import 'package:mobiles_labs_5th_semester/presentation/home_page/bloc/state.dart';
 
+import '../../components/utils/debounce.dart';
 import '../../data/repositories/games_repository.dart';
+import 'bloc/state.dart';
 
 part 'gameCard.dart';
 
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key, required this.title});
+class HomePage extends StatefulWidget {
+  const HomePage({super.key, required this.title});
 
   final String title;
 
   @override
-  State<MyHomePage> createState() => _MyHomePageState();
+  State<HomePage> createState() => _HomePageState();
 }
 
-class _MyHomePageState extends State<MyHomePage> {
+class _HomePageState extends State<HomePage> {
   @override
   void initState() {
     super.initState();
@@ -50,14 +57,39 @@ class Body extends StatefulWidget {
 class _BodyState extends State<Body> {
   late Future<List<GameData>?> data;
   final searchController = TextEditingController();
-  final repo = GamesRepository();
+  final scrollController = ScrollController();
+
+  // final repo = GamesRepository();
 
   @override
   void initState() {
-    data = repo.loadData(null);
+    //добавление кастомного события
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      context.read<HomeBloc>().add(const HomeLoadDataEvent());
+    });
+
+    scrollController.addListener(_onNextPageListener);
     super.initState();
   }
 
+  void _onNextPageListener() {
+    if (scrollController.offset >= scrollController.position.maxScrollExtent) {
+      final bloc = context.read<HomeBloc>();
+      if (!bloc.state.isPaginationLoading) {
+        bloc.add(HomeLoadDataEvent(
+          search: searchController.text,
+          nextPage: bloc.state.data?.nextPage,
+        ));
+      }
+    }
+  }
+
+  @override
+  void dispose() {
+    searchController.dispose();
+    scrollController.dispose();
+    super.dispose();
+  }
 
   @override
   Widget build(BuildContext context) {
@@ -71,37 +103,61 @@ class _BodyState extends State<Body> {
             // borderRadius: const BorderRadiusTween(2.0),
             controller: searchController,
             onChanged: (search) {
-              setState(() {
-                data = repo.loadData(search);
-              });
+              Debounce.run(() => context
+                  .read<HomeBloc>()
+                  .add(HomeLoadDataEvent(search: search)));
             },
           ),
         ),
-        Expanded(
-          child: Center(
-            child: FutureBuilder<List<GameData>?>(
-              future: data,
-              builder: (context, snapshot) => SingleChildScrollView(
-                  child: snapshot.hasData
-                      ? Column(
-                          children: snapshot.data?.map((data) {
-                                return _GameCard.fromData(
+        BlocBuilder<HomeBloc, HomeState>(
+          builder: (context, state) => state.error != null
+              ? Text(
+                  state.error ?? '',
+                  style: Theme.of(context)
+                      .textTheme
+                      .headlineSmall
+                      ?.copyWith(color: Colors.red),
+                )
+              : state.isLoading
+                  ? const CircularProgressIndicator()
+                  : Expanded(
+                      child: RefreshIndicator(
+                        onRefresh: _onRefresh,
+                        child: ListView.builder(
+                          controller: scrollController,
+                          itemCount: state.data?.data?.length ?? 0,
+                          itemBuilder: (context, index) {
+                            final data = state.data?.data?[index];
+                            return data != null
+                                ? _GameCard.fromData(
                                     data,
-                                  onLike: (String title, bool isLiked) =>
+                                    onLike: (title, isLiked) =>
                                         _showSnackBar(context, title, isLiked),
                                     onTap: () => _navToDetails(context, data),
-                                );
-                              }).toList() ??
-                              [])
-                      : const CircularProgressIndicator()
+                                  )
+                                : const SizedBox.shrink();
+                          },
                         ),
                       ),
                     ),
         ),
+        //значок загрузки при пагинации
+        BlocBuilder<HomeBloc, HomeState>(
+          builder: (context, state) => state.isPaginationLoading
+              ? const CircularProgressIndicator()
+              : const SizedBox.shrink(),
+        )
       ],
     );
   }
 
+  Future<void> _onRefresh() {
+    context
+        .read<HomeBloc>()
+        .add(HomeLoadDataEvent(search: searchController.text));
+    return Future.value(null);
+  }
+
   void _showSnackBar(BuildContext context, String title, bool isLiked) {
     WidgetsBinding.instance.addPostFrameCallback((_) {
       ScaffoldMessenger.of(context).showSnackBar(SnackBar(

pubspec.lock

@@ -38,6 +38,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.11.0"
+  bloc:
+    dependency: transitive
+    description:
+      name: bloc
+      sha256: "106842ad6569f0b60297619e9e0b1885c2fb9bf84812935490e6c5275777804e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.1.4"
   boolean_selector:
     dependency: transitive
     description:
@@ -158,6 +166,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.1.2"
+  copy_with_extension:
+    dependency: transitive
+    description:
+      name: copy_with_extension
+      sha256: fbcf890b0c34aedf0894f91a11a579994b61b4e04080204656b582708b5b1125
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.0.4"
+  copy_with_extension_gen:
+    dependency: "direct main"
+    description:
+      name: copy_with_extension_gen
+      sha256: "51cd11094096d40824c8da629ca7f16f3b7cea5fc44132b679617483d43346b0"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.0.4"
   crypto:
     dependency: transitive
     description:
@@ -206,6 +230,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.0.0"
+  equatable:
+    dependency: "direct main"
+    description:
+      name: equatable
+      sha256: c2b87cb7756efdf69892005af546c56c0b5037f54d2a88269b4f347a505e3ca2
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.0.5"
   fake_async:
     dependency: transitive
     description:
@@ -235,6 +267,14 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_bloc:
+    dependency: "direct main"
+    description:
+      name: flutter_bloc
+      sha256: b594505eac31a0518bdcb4b5b79573b8d9117b193cc80cc12e17d639b10aa27a
+      url: "https://pub.dev"
+    source: hosted
+    version: "8.1.6"
   flutter_lints:
     dependency: "direct dev"
     description:
@@ -408,6 +448,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.0.0"
+  nested:
+    dependency: transitive
+    description:
+      name: nested
+      sha256: "03bac4c528c64c95c722ec99280375a6f2fc708eec17c7b3f07253b626cd2a20"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.0"
   package_config:
     dependency: transitive
     description:
@@ -440,6 +488,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
+  provider:
+    dependency: transitive
+    description:
+      name: provider
+      sha256: c8a055ee5ce3fd98d6fc872478b03823ffdb448699c6ebdbbc71d59b596fd48c
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.1.2"
   pub_semver:
     dependency: transitive
     description:

pubspec.yaml

@@ -17,6 +17,9 @@ dependencies:
   pretty_dio_logger: ^1.3.1
   # чтобы получить нормальное описание без html тегов
   html: ^0.15.0
+  flutter_bloc: ^8.1.6
+  equatable: ^2.0.5
+  copy_with_extension_gen: ^5.0.4
 
 dev_dependencies:
   flutter_test: