
Fl-Query
Asynchronous data caching, refetching & invalidation library for Flutter. FL-Query lets you manage & distribute your async data without touching any global state
Fl-Query makes asynchronous server state management a breeze in flutter
# Features
- Async data caching & management
- Smart + effective refetching
- Optimistic updates
- Automatically cached data invalidation & unneeded query/mutation garbage collection
- Infinite pagination via `InfiniteQuery`
- Lazy persistent cache (Uses [hive](https://pub.dev/packages/hive) for persisting query results to disk) (optional)
- Easy to write & understand code. Follows DRY (Don't repeat yourself) convention
- Compatible with both vanilla Flutter & elite [flutter_hooks](https://pub.dev/packages/flutter_hooks)
# Installation
Regular installation:
```bash
$ flutter pub add fl_query
```
For elite flutter_hooks user (Welcome to the flutter cool community btw😎)
```bash
$ flutter pub add flutter_hooks fl_query_hooks
```
# Docs
You can find the documentation of fl-query at https://fl-query.vercel.app/
# Basic Usage
Initialize the cache databases in your `main` method
> fl-query uses [hive](https://pub.dev/packages/hive) for persisting data to disk
```dart
void main()async {
WidgetsFlutterBinding.ensureInitialized();
await QueryClient.initialize(cachePrefix: 'fl_query_example');
runApp(MyApp());
}
```
In `MyApp` Widget's build method wrap your `MaterialApp` with with `QueryClientProvider` widget
```dart
Widget build(BuildContext context) {
return QueryClientProvider(
child: MaterialApp(
title: 'Fl-Query Example App',
theme: ThemeData(
useMaterial3: true,
primarySwatch: Colors.blue,
),
home: const MyHomePage(),
),
);
}
```
Let's write use a `Query` now
FL-Query provides a `QueryBuilder` widget that creates and listens to the specified `Query`
and re-runs the builder function whenever there's an update
It has 2 required parameters(unnamed) `key` & `builder`
```dart
class MyApp extends StatelessWidget{
MyApp({super.key});
@override
build(context){
return QueryBuilder(
'hello',
() {
return Future.delayed(
const Duration(seconds: 6), () => 'Hello World!');
},
initial: 'A replacement',
jsonConfig: JsonConfig(
fromJson: (json) => json['data'],
toJson: (data) => {'data': data},
),
onData: (value) {
debugPrint('onData: $value');
},
onError: (error) {
debugPrint('onError: $error');
},
builder: (context, query) {
if (query.isLoading) {
return const Center(
child: CircularProgressIndicator(),
);
} else if (query.hasError) {
return Center(
child: Text(query.error.toString()),
);
}
return Center(
child: Text(query.data ?? "Unfortunately, there's no data"),
);
},
);
}
}
```
And if you're using **flutter_hooks** you got that too
```dart
class MyApp extends HookWidget{
MyApp({super.key});
@override
build(context){
final query = useQuery(
'hello',
() {
return Future.delayed(
const Duration(seconds: 6), () => 'Hello World!');
},
initial: 'A replacement',
jsonConfig: JsonConfig(
fromJson: (json) => json['data'],
toJson: (data) => {'data': data},
),
onData: (value) {
debugPrint('onData: $value');
},
onError: (error) {
debugPrint('onError: $error');
},
);
if (query.isLoading) {
return const Center(
child: CircularProgressIndicator(),
);
} else if (query.hasError) {
return Center(
child: Text(query.error.toString()),
);
}
return Center(
child: Text(query.data ?? "Unfortunately, there's no data"),
);
}
}
```
*To master the fl-query follow the official blog at https://fl-query.vercel.app/blog*
# Why?
The main purpose of Fl-Query is providing the easiest way to manage the messy server-state part requiring the least amount of code with code reusability & performance
This let's you focus more on those cool UI animations & transitions✨. Leave the boring stuff to fl-query
**Q. Isn't `FutureBuilder` good?**
No, of course not. Unless you're from 2013 or your app is a purely offline app
**Q. So `FutureProvider` from riverpod or provider not enough?**
Probably yes. Although riverpod@v2 has added a lot of caching related features but still optimistic updates, periodic refetching & disk persistence are missing. Let's not forget about infinite pagination, it's a nightmare😅. In case of provider, same story. It's a great package but it's not ideal for server-state management
# Notice Board
We need some bada** coders to write tests and ruin our life🥲
100% coverage is our goal🙃