store_builder 0.2.3

Flux store and builder for Flutter

store_builder

Flux store and builder for Flutter.

Install

See pub.dartlang.org/packages/store_builder

Description

store_builder provides Store, Value and StoreBuilder.

Store represents the state of the entire app. It can have multiple Values.

Value is a single value in the Store that identified by name.

StoreBuilder is a Widget that bind with a Value and rebuilt when the Value is updated.

Usage

Add StoreProvider and Store to your app. It makes your widgets allows to access the Store.

void main() => runApp(MaterialApp(
      title: 'Your app',
      home: StoreProvider(
        store: Store(),
        child: MyHomePage(),
      ),
    ));

Use StoreBuilder<V> to build widgets with a value. It is bind to individual values in the Store by name.

child: StoreBuilder<int>(
  name: "counter",
  builder: (BuildContext context, Value<int> value) {
    if (value.error != null) {
        return ErrorWidget(value.error);
    } else if (value.value == null) {
        return LoadingWidget();
    }
    return YourWidget(value.value);
  },
),

You can gets a Value from Store by Store#value method, and gets the value by Value#value property.

// gets a Value.
final Value<int> value = store.value<int>("counter");

// Value has value and error.
final int counter = value.value ?? 0;
// final Object error = value.error;

// Update the value.
value.value = counter + 1;

When a Value is updates by Value#value and Value#error, all StoreBuilders associated with that name are rebuilt.

For separation of responsibility, we recommend that you implement store operations independently as Actions.

class Names {
  static const String counter = 'counter';
  
  ...
  
}

class Values {
  static Value<int> counter(Store store)
      => store.value<int>(Names.counter);
  
  ...
  
}

class IncrementCounterAction implements Action {
  Future<void> run(Store store) async {
    final Value<int> value = Values.counter(store);
    final int counter = value.value ?? 0;
    value.value = counter + 1;
  }
}

And widgets calls the action.

class YourWidget extends StatelessWidget {
  
  ...
  
  void incrementCounter() {
    Store.of(context).action(IncrementCounterAction());
  }
}