amplify_datastore 1.1.0-supports-only-mobile amplify_datastore: ^1.1.0-supports-only-mobile copied to clipboard
The Amplify Flutter DataStore category plugin, providing a queryable, on-device data store.
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
library sample_app;
import 'dart:async';
import 'package:amplify_datastore/amplify_datastore.dart';
// Uncomment the below line to enable online sync
// import 'package:amplify_api/amplify_api.dart';
import 'package:amplify_flutter/amplify_flutter.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'models/ModelProvider.dart';
part 'event_display_widgets.dart';
part 'queries_display_widgets.dart';
part 'save_model_widgets.dart';
void main() {
runApp(MyApp());
}
final divider = VerticalDivider(
color: Colors.white,
width: 10,
);
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
List<Post> _posts = <Post>[];
List<Comment> _comments = <Comment>[];
List<Blog> _blogs = <Blog>[];
List<String> _postStreamingData = <String>[];
List<String> _blogStreamingData = <String>[];
List<String> _commentStreamingData = <String>[];
bool _isAmplifyConfigured = false;
String _queriesToView = "Post"; //default view
Blog? _selectedBlogForNewPost;
Post? _selectedPostForNewComment;
late Stream<SubscriptionEvent<Post>> postStream;
late Stream<SubscriptionEvent<Blog>> blogStream;
late Stream<SubscriptionEvent<Comment>> commentStream;
late StreamSubscription<DataStoreHubEvent> hubSubscription;
bool _listeningToHub = true;
late AmplifyDataStore datastorePlugin;
final _titleController = TextEditingController();
final _ratingController = TextEditingController();
final _nameController = TextEditingController();
final _contentController = TextEditingController();
ScrollController _postScrollController =
ScrollController(initialScrollOffset: 50.0);
ScrollController _blogScrollController =
ScrollController(initialScrollOffset: 50.0);
ScrollController _commentScrollController =
ScrollController(initialScrollOffset: 50.0);
@override
void initState() {
super.initState();
initPlatformState();
}
// Platform messages are asynchronous, so we initialize in an async method.
Future<void> initPlatformState() async {
try {
datastorePlugin = AmplifyDataStore(
modelProvider: ModelProvider.instance,
errorHandler: ((error) =>
{print("Custom ErrorHandler received: " + error.toString())}),
);
await Amplify.addPlugin(datastorePlugin);
// Configure
// Uncomment the below lines to enable online sync.
// await Amplify.addPlugin(AmplifyAPI());
// await Amplify.configure(amplifyconfig);
// Remove this line when using the lines above for online sync
await Amplify.configure("{}");
} on AmplifyAlreadyConfiguredException {
print(
'Amplify was already configured. Looks like app restarted on android.');
}
listenToHub();
Amplify.DataStore.observeQuery(
Blog.classType,
).listen((QuerySnapshot<Blog> snapshot) {
var count = snapshot.items.length;
var now = DateTime.now().toIso8601String();
bool status = snapshot.isSynced;
print(
'[Observe Query] Blog snapshot received with $count models, status: $status at $now');
setState(() {
_blogs = snapshot.items;
});
});
Amplify.DataStore.observeQuery(
Post.classType,
).listen((QuerySnapshot<Post> snapshot) {
setState(() {
_posts = snapshot.items;
});
});
Amplify.DataStore.observeQuery(
Comment.classType,
).listen((QuerySnapshot<Comment> snapshot) {
setState(() {
_comments = snapshot.items;
});
});
// setup streams
postStream = Amplify.DataStore.observe(Post.classType);
postStream.listen((event) {
_postStreamingData.add('Post: ' +
(event.eventType.toString() == EventType.delete.toString()
? event.item.id
: event.item.title) +
', of type: ' +
event.eventType.toString());
}).onError((error) => print(error));
blogStream = Amplify.DataStore.observe(Blog.classType);
blogStream.listen((event) {
_blogStreamingData.add('Blog: ' +
(event.eventType.toString() == EventType.delete.toString()
? event.item.id
: event.item.name) +
', of type: ' +
event.eventType.toString());
}).onError((error) => print(error));
commentStream = Amplify.DataStore.observe(Comment.classType);
commentStream.listen((event) {
_commentStreamingData.add('Comment: ' +
(event.eventType.toString() == EventType.delete.toString()
? event.item.id
: event.item.content) +
', of type: ' +
event.eventType.toString());
}).onError((error) => print(error));
setState(() {
_isAmplifyConfigured = true;
});
}
void listenToHub() {
setState(() {
hubSubscription = Amplify.Hub.listen(HubChannel.DataStore, (msg) {
if (msg is NetworkStatusEvent) {
print('Network status message: $msg');
return;
}
print(msg);
});
_listeningToHub = true;
});
}
void stopListeningToHub() {
hubSubscription.cancel();
setState(() {
_listeningToHub = false;
});
}
savePost(String title, int rating, Blog associatedBlog) async {
try {
Post post = Post(
title: title,
rating: rating,
created: TemporalDateTime.now(),
blog: associatedBlog);
await Amplify.DataStore.save(post);
} catch (e) {
print(e);
}
}
saveBlog(String name) async {
try {
Blog blog = Blog(
name: name,
);
await Amplify.DataStore.save(blog);
} catch (e) {
print(e);
}
}
saveComment(String content, Post associatedPost) async {
try {
Comment comment = Comment(content: content, post: associatedPost);
await Amplify.DataStore.save(comment);
} catch (e) {
print(e);
}
}
deletePost(String id) async {
try {
_selectedPostForNewComment = null;
await Amplify.DataStore.delete(
Post(id: id, title: "", rating: 0, created: TemporalDateTime.now()));
} catch (e) {
print(e);
}
}
deleteBlog(String id) async {
try {
_selectedBlogForNewPost = null;
await Amplify.DataStore.delete(Blog(id: id, name: ""));
} catch (e) {
print(e);
}
}
deleteComment(String id) async {
try {
await Amplify.DataStore.delete(Comment(id: id, content: ""));
} catch (e) {
print(e);
}
}
@override
Widget build(BuildContext context) {
executeAfterBuild();
return MaterialApp(
home: Scaffold(
appBar: AppBar(
centerTitle: true,
title: Text(
'Best DataStore App Ever',
textAlign: TextAlign.center,
),
actions: <Widget>[
Padding(
padding: EdgeInsets.only(right: 20.0),
child: GestureDetector(
onTap: () async {
await Amplify.DataStore.clear();
},
child: Icon(
Icons.clear,
semanticLabel: "Clear",
size: 24.0,
),
)),
],
),
body: Column(
children: <Widget>[
Padding(padding: EdgeInsets.all(10.0)),
// Row for saving blog
addBlogWidget(_nameController, _isAmplifyConfigured, saveBlog),
// Row for saving post
addPostWidget(
titleController: _titleController,
ratingController: _ratingController,
isAmplifyConfigured: _isAmplifyConfigured,
allBlogs: _blogs,
saveFn: savePost,
app: this,
defaultBlog: _selectedBlogForNewPost),
// Row for saving comment
addCommentWidget(_contentController, _isAmplifyConfigured,
_selectedPostForNewComment, _posts, saveComment, this),
Padding(padding: EdgeInsets.all(10.0)),
// Row for query buttons
displayQueryButtons(_isAmplifyConfigured, this),
Padding(padding: EdgeInsets.all(5.0)),
Text("Listen to DataStore Hub"),
Switch(
value: _listeningToHub,
onChanged: (value) {
if (_listeningToHub) {
stopListeningToHub();
} else {
listenToHub();
}
},
activeTrackColor: Colors.lightGreenAccent,
activeColor: Colors.green,
),
Padding(padding: EdgeInsets.all(5.0)),
// Showing relevant queries
if (_queriesToView == "Post")
getWidgetToDisplayPost(_posts, deletePost, _blogs)
else if (_queriesToView == "Blog")
getWidgetToDisplayBlog(_blogs, deleteBlog)
else if (_queriesToView == "Comment")
getWidgetToDisplayComment(_comments, deleteComment, _posts),
Text(_queriesToView + " Events",
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 14)),
Padding(padding: EdgeInsets.all(5.0)),
if (_queriesToView == "Post")
getWidgetToDisplayPostEvents(
_postScrollController, _postStreamingData, executeAfterBuild)
else if (_queriesToView == "Blog")
getWidgetToDisplayBlogEvents(
_blogScrollController, _blogStreamingData, executeAfterBuild)
else if (_queriesToView == "Comment")
getWidgetToDisplayCommentEvents(_commentScrollController,
_commentStreamingData, executeAfterBuild),
],
// replace with any or all query results as needed
),
),
);
}
@override
void didChangeDependencies() {
super.didChangeDependencies();
WidgetsBinding.instance.addPostFrameCallback((_) => executeAfterBuild());
}
Future<void> executeAfterBuild() async {
// this code will get executed after the build method
// because of the way async functions are scheduled
Future.delayed(const Duration(milliseconds: 500), () {
if (_postScrollController.hasClients)
_postScrollController.animateTo(
_postScrollController.position.maxScrollExtent,
duration: Duration(milliseconds: 200),
curve: Curves.easeOut);
if (_blogScrollController.hasClients)
_blogScrollController.animateTo(
_blogScrollController.position.maxScrollExtent,
duration: Duration(milliseconds: 200),
curve: Curves.easeOut);
if (_commentScrollController.hasClients)
_commentScrollController.animateTo(
_commentScrollController.position.maxScrollExtent,
duration: Duration(milliseconds: 200),
curve: Curves.easeOut);
});
}
}