ajwah_bloc
Rx based state management library. Manage your application's states, effects, and actions easy way.
States
Every state class must derived from BaseState<T>
class. And it is mandatory to pass the
state name
and initialState
. The BaseState<T>
class has one abstract method T reduce(T state, Action action);
. This method should be invoked by sysytem passing current state and action. You should mutate the state based on action.
Example
import 'package:ajwah_bloc/ajwah_bloc.dart';
import 'package:ajwah_block_examples/actionTypes.dart';
class CounterModel {
final int count;
final bool isLoading;
CounterModel({this.count, this.isLoading});
CounterModel.init() : this(count: 0, isLoading: false);
CounterModel.countData(int count) : this(count: count, isLoading: false);
CounterModel.loading(int count) : this(count: count, isLoading: true);
}
class CounterState extends BaseState<CounterModel> {
CounterState() : super(name: 'counter', initialState: CounterModel.init());
CounterModel reduce(CounterModel state, Action action) {
switch (action.type) {
case ActionTypes.Inc:
return CounterModel.countData(state.count + 1);
case ActionTypes.Dec:
return CounterModel.countData(state.count - 1);
case ActionTypes.AsyncInc:
return CounterModel.loading(state.count);
default:
return state;
}
}
}
Effects
Every effect class must derived from BaseEffect
class. And it is optional to pass the
effectKey
. But it's mandatory if you want conditionally remove the effects by using
store.removeEffectsByKey('effectKey')
. The BaseEffect
class has one abstract method List<Observable<Action>> registerEffects(Actions action$, Store store$);
. This function should be invoked by system passing reference of Actions and Store classes. Please keep in mind that effects should not work until you register them.
Example
import 'package:ajwah_bloc/ajwah_bloc.dart';
import 'package:rxdart/rxdart.dart';
import '../../actionTypes.dart';
class CounterEffect extends BaseEffect {
Observable<Action> effectForAsyncInc(Actions action$, Store store$) {
return action$
.ofType(ActionTypes.AsyncInc)
.debounceTime(Duration(milliseconds: 500))
.mapTo(Action(type: ActionTypes.Inc));
}
List<Observable<Action>> registerEffects(Actions action$, Store store$) {
return [effectForAsyncInc(action$, store$)];
}
}
Using state in components
Ajwah provides a comfortable way to use states in components and dispatching actions.
Just call the createStore(states:[], effects:[])
method from main()
function. Now store
instance should be available by the helper function store()
throughout the application.
Note: createStore(...)
method return store instance so that you can make a sate provider class(InheritedWidget) as your convenient.
We can use select
method to get state
data (passing state name): store().select('counter')
. or store().select2(...)
This method return a Observable<T>
type object. Now we can use StreamBuilder
object to make reactive widgets.
Example
StreamBuilder<CounterModel>(
stream: store().select<CounterModel>('counter'),
builder:(BuildContext context, AsyncSnapshot<CounterModel> snapshot) {
if (snapshot.data.isLoading) {
return CircularProgressIndicator();
}
return Text(
snapshot.data.count.toString(),
style: Theme.of(context).textTheme.title,
);
},
)
And also for dispatching state's action - we can use dispatch(actionType:'any')
or store().dispatch(Action(type:'any', payload:any))
method.
CounterComponent
import 'package:ajwah_bloc/ajwah_bloc.dart';
import 'package:ajwah_block_examples/actionTypes.dart';
import 'package:ajwah_block_examples/counter/store/counterState.dart';
import 'package:flutter_web/cupertino.dart';
import 'package:flutter_web/material.dart';
class CounterComponent extends StatelessWidget {
const CounterComponent({Key key}) : super(key: key);
void increment() {
dispatch(actionType: ActionTypes.Inc);
}
void decrement() {
dispatch(actionType: ActionTypes.Dec);
}
void asyncIncrement() {
dispatch(actionType: ActionTypes.AsyncInc);
}
@override
Widget build(BuildContext context) {
return Row(
children: <Widget>[
ButtonBar(mainAxisSize: MainAxisSize.min, children: <Widget>[
RaisedButton(
textColor: Colors.white,
color: Colors.blue,
child: Icon(Icons.add),
onPressed: increment,
),
new RaisedButton(
textColor: Colors.white,
color: Colors.blue,
child: Text('Async(+)'),
onPressed: asyncIncrement,
),
RaisedButton(
textColor: Colors.white,
color: Colors.blue,
child: Icon(Icons.remove),
onPressed: decrement,
)
]),
SizedBox(
width: 10.0,
),
StreamBuilder<CounterModel>(
stream: store().select<CounterModel>('counter')
builder:
(BuildContext context, AsyncSnapshot<CounterModel> snapshot) {
if (snapshot.data.isLoading) {
return CircularProgressIndicator();
}
return Text(
snapshot.data.count.toString(),
style: Theme.of(context).textTheme.title,
);
},
)
],
);
}
}