rebuilder

Description:

rebuilder

rebuilder #
Rebuilder is an easy and minimalistic state management library for Flutter.
It consists of:


A DataModel class to extend to create a class where lives the data and the business logic for the UI.


A DataModelProvider that provides this model to the widgets tree by using an InheritedWidget.


A RebuilderState that holds the state of a Rebuilder widget.


The Rebuilder widget that represents the entity which rebuilds every time the rebuild method of the associated RebuilderState's state property is called.


The RebuilderObject: an object bound to a RebuilderState in order to rebuild the Rebuilder widget associated to this state whenever a new value is set.


Examples built with this library:


Rebuilder example. Check out the example app to know how to:

Implement a counter
Use the DataModel to separate the UI from the business logic
Implement a dynamic theme changer with a RebuilderObject
Bind a function to a RebuilderObject
Sharing data between widgets
Update only a subtree of widgets



Quiz game: a simple trivia game built with Flutter and this package.


Getting started #
1. Define a DataModel
class CountersModel extends DataModel {
CountersModel() {

// Initialize the instance of the `RebuilderObject` with
// with an instance of a `RebuilderState` that will be bound
// to a `Rebuilder` widget.
counterDown = RebuilderObject<int>.init(
rebuilderState: counterDownState,
initialData: 100,
onChange: _onCounterDownChange);
}

// STATES
final counterUpState = RebuilderState();
final counterDownState = RebuilderState();
final counterMulState = RebuilderState();

// COUNTERS
int counterUp = 0;
int counterMul = 2;
RebuilderObject<int> counterDown;

// METHODS
void incrementCounterUp() {
counterUp++;
counterUpState.rebuild();
}

void decrementCounterDown() {
counterDown.value--;

// Using the `RebuilderObject` the `rebuild` method of the
// counterDownState will automatically be called.
//
// states.counterDownState.rebuild();
}

void _onCounterDownChange() {
print('Value changed: ${counterDown.value}');
}

@override
void dispose() {}
}
copied to clipboard
2. Provide the CountersModel by using the DataModelProvider widget
final countersModel = CountersModel()

DataModelProvider<CountersModel>(
dataModel: countersModel,
child: const CountersPage(),
);
copied to clipboard
3. Get the CountersModel instance from the context of a widget in the tree
Widget build(BuildContext context) {
final countersModel = DataModelProvider.of<CountersModel>(context);
copied to clipboard
4. Bind the RebuilderState instances to the Rebuilder widgets in the view
Rebuilder<CountersModel>(
dataModel: countersModel,
rebuilderState: countersModel.counterUpState,
builder: (state, data) {
// Accessing to `counterUp` in the `DataModel`
// derived class provided through the `data` parameter
return Text('${data.counterUp}');
//
// It is possible to directly access to `counterUp`
// without using the `dataModel` parameter:
//
// builder: (state, _) {
// return Text('${countersModel.counterUp}');
}),
RaisedButton(
child: const Text('+'),
onPressed: countersModel.incrementCounterUp,
),



Rebuilder<RebuilderObject>(
dataModel: countersModel.counterDown,
rebuilderState: countersModel.counterDownState,
builder: (state, data) {
return Text('${data.value}');
}),
RaisedButton(
child: const Text('-'),
onPressed: countersModel.decrementCounterDown,
)



Rebuilder<CountersModel>(
dataModel: countersModel,
rebuilderState: countersModel.counterMulState,
builder: (state, data) {
return Column(children: <Widget>[
Text('${data.counterMul}'),
RaisedButton(
child: const Text('*'),
onPressed: () {
data.counterMul *= 2;
if (data.counterMul > 65536) {
data.counterMul = 2;
}
state.rebuild();
}),
]);
}),
copied to clipboard