Release 0.11.0 (#26)

Author: klisiewicz

.gitignore

@@ -71,3 +71,6 @@ build/
 !**/ios/**/default.pbxuser
 !**/ios/**/default.perspectivev3
 !/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages
+
+# Test Coverage
+coverage

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## [0.11.0]
+
+* Migrating to `bloc` 8.1.x and `flutter_bloc` 8.1.x,
+* `ConnectionBloc` - a BLoC that exposes the Internet connection state to the UI.
+
 ## [0.10.0]
 
 * Migrating to `bloc` 8.0.x and `flutter_bloc` 8.0.x,

README.md

@@ -32,7 +32,6 @@ A `Repository` to handles data operations. It knows where to get the data from a
 * `onEmpty` - informs the presentation layer that the loading is completed, but `null` or empty data was retrieved,
 * `onError` - informs the presentation layer that the loading or refreshing has ended with an error. It also provides an error that has occurred.
 
-
 ## Features
 
 ### ListBloc
@@ -117,6 +116,7 @@ Where:
 [Paged List BLoC Sample App](example/lib/src/list_paged_filter_app.dart)
 
 ### DetailsBloc
+
 A BLoC that allows to fetch a single item with given identifier.
 
 #### DetailsRepository
@@ -132,6 +132,62 @@ Where:
 
 [List/Details BLoC Sample App](example/lib/src/list_details_app.dart)
 
+### ConnectionBloc
+
+A BLoC that exposes the Internet connection state to the UI.
+
+#### Connection
+
+The Internet connection state. It can be either `online` or `offline`.
+
+#### ConnectionRepository
+
+`ConnectionRepository` notifies about connection state changes, such as going online or offline. 
+
+Please notice, that this is only a contract and a developer needs to provide an implementation. This can be done using one of many popular packages, like:
+
+* [connectivity_plus](https://pub.dev/packages/connectivity_plus)
+* [internet_connection_checker](https://pub.dev/packages/internet_connection_checker)
+
+Or whatever works for you. A sample implementation using `connectivity_plus` may look as follows:
+
+```dart
+class ConnectivityPlusRepository implements ConnectionRepository {
+  @override
+  Stream<Connection> observe() {
+    return connectivity.onConnectivityChanged.map(
+      (ConnectivityResult result) => result != ConnectivityResult.none
+          ? Connection.online
+          : Connection.offline,
+    );
+  }
+}
+```
+
+#### ConnectionBuilder
+
+`ConnectionBuilder` is responsible for building the UI based `Connection` state.
+
+It's a wrapper over the `BlocBuilder` widget so it accepts a `bloc` object and provides `WidgetBuilder` functions for possible states:
+
+* `onOnline` - a builder for the the `Connection.online` state,
+* `onOffline` - a builder for the the `Connection.offline` state,
+
+#### ConnectionListener
+
+`ConnectionListener` is responsible for performing a one-time action based on the `Connection` state change.
+
+It should be used for functionality that needs to occur only once in response to the `Connection` state change such as navigation, `SnackBar`, showing a `Dialog`, etc.
+
+`ConnectionListener` is a wrapper over the `BlocListener` widget so it accepts a `bloc` object as well as a `child` widget. It also takes `ConnectionCallback` functions for possible states:
+
+* `onOnline` - a callback for the the `Connection.online` state,
+* `onOffline` - a callback for the `Connection.offline` state.
+
+#### Usage:
+
+[Connection Sample App](example/lib/src/connection_app.dart)
+
 ## Dart version
 
 - Dart 2: >= 2.12.0

analysis_options.yaml

@@ -1 +1,7 @@
 include: package:lint/analysis_options.yaml
+lintner:
+  rules:
+    always_specify_types: true
+    avoid_classes_with_only_static_members: true
+    lines_longer_than_80_chars: true
+    prefer_single_quotes: true

example/lib/src/album/ui/photos_list_empty.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
 
 class PhotosListEmpty extends StatelessWidget {
-  const PhotosListEmpty({Key? key}) : super(key: key);
+  const PhotosListEmpty({super.key});
 
   @override
   Widget build(BuildContext context) {

example/lib/src/album/ui/photos_list_paged.dart

@@ -10,14 +10,14 @@ class PhotosListPaged extends StatelessWidget {
 
   const PhotosListPaged(
     this.page, {
-    Key? key,
+    super.key,
     required this.onLoadNextPage,
-  }) : super(key: key);
+  });
 
   @override
   Widget build(BuildContext context) {
     return InfiniteListView.separated(
-      itemBuilder: (context, index) => _PhotoGridItem(page.items[index]),
+      itemBuilder: (context, index) => PhotoGridItem(page.items[index]),
       separatorBuilder: (context, index) => const Divider(),
       itemCount: page.items.length,
       hasNext: page.hasMoreItems,
@@ -27,13 +27,13 @@ class PhotosListPaged extends StatelessWidget {
   }
 }
 
-class _PhotoGridItem extends StatelessWidget {
+class PhotoGridItem extends StatelessWidget {
   final Photo photo;
 
-  const _PhotoGridItem(
+  const PhotoGridItem(
     this.photo, {
-    Key? key,
-  }) : super(key: key);
+    super.key,
+  });
 
   @override
   Widget build(BuildContext context) {

example/lib/src/common/error_message.dart

@@ -3,10 +3,7 @@ import 'package:flutter/widgets.dart';
 class ErrorMessage extends StatelessWidget {
   final Object error;
 
-  const ErrorMessage({
-    required this.error,
-    Key? key,
-  }) : super(key: key);
+  const ErrorMessage({required this.error, super.key});
 
   @override
   Widget build(BuildContext context) {

example/lib/src/common/loading_indicator.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
 
 class LoadingIndicator extends StatelessWidget {
-  const LoadingIndicator({Key? key}) : super(key: key);
+  const LoadingIndicator({super.key});
 
   @override
   Widget build(BuildContext context) {

example/lib/src/common/loading_page_indicator.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
 
 class LoadingPageIndicator extends StatelessWidget {
-  const LoadingPageIndicator({Key? key}) : super(key: key);
+  const LoadingPageIndicator({super.key});
 
   @override
   Widget build(BuildContext context) {

example/lib/src/connection_app.dart

@@ -0,0 +1,105 @@
+import 'package:connectivity_plus/connectivity_plus.dart';
+import 'package:example/src/list_app.dart';
+import 'package:example/src/post/model/post.dart';
+import 'package:example/src/post/model/post_repository.dart';
+import 'package:example/src/tools/connection/connectivity_plus_repository.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:flutter_bloc_patterns/base_list.dart';
+import 'package:flutter_bloc_patterns/connection.dart';
+
+void main() => runApp(ConnectionApp());
+
+typedef PostsBloc = ListBloc<Post>;
+
+class ConnectionApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Connection App',
+      theme: ThemeData(primarySwatch: Colors.green),
+      home: MultiBlocProvider(
+        providers: [
+          BlocProvider(
+            create: (_) => ListBloc<Post>(PostListRepository()),
+          ),
+          BlocProvider(
+            create: (_) => ConnectionBloc(
+              ConnectivityPlusRepository(Connectivity()),
+            ),
+          ),
+        ],
+        child: const ConnectionPage(),
+      ),
+    );
+  }
+}
+
+class ConnectionPage extends StatefulWidget {
+  const ConnectionPage({super.key});
+
+  @override
+  State<ConnectionPage> createState() => _ConnectionPageState();
+}
+
+class _ConnectionPageState extends State<ConnectionPage> {
+  @override
+  void initState() {
+    super.initState();
+    context.read<PostsBloc>().loadItems();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('Posts')),
+      body: ConnectionListener(
+        onOnline: _showOnlineSnackbar,
+        onOffline: _showOfflineSnackbar,
+        child: ConnectionBuilder(
+          onOnline: (context) => const PostsViewStateBuilder(),
+          onOffline: (context) => const OfflineView(),
+        ),
+      ),
+    );
+  }
+
+  void _showOnlineSnackbar(BuildContext context) {
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: const Text('You are back online.'),
+        backgroundColor: Colors.green[300],
+      ),
+    );
+  }
+
+  void _showOfflineSnackbar(BuildContext context) {
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: const Text('You are offline.'),
+        backgroundColor: Colors.red[300],
+      ),
+    );
+  }
+}
+
+class OfflineView extends StatelessWidget {
+  const OfflineView({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Center(
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        children: [
+          const Icon(Icons.signal_wifi_0_bar_rounded, size: 64),
+          const SizedBox(height: 16),
+          Text(
+            'You are offline. Check your Internet connection.',
+            style: Theme.of(context).textTheme.bodyText2,
+          )
+        ],
+      ),
+    );
+  }
+}