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Description:

shared value

Shared Value #
A wrapper over InheritedModel, this module allows
you to easily manage global state in flutter apps.
At a high level, SharedValue puts your variables in an intelligent "container" that is flutter-aware.
It can be viewed as a low-boilerplate generalization of the Provider state management solution.
Usage #
1. Initialize
IMPORTANT: Always declare SharedValue variables as final, so you don't accidentally over-write the SharedValue
object
(which you generally don't want to do.)
// This global SharedValue can be shared across the entire app
// IMPORTANT: Variable declared as final
final SharedValue<int> counter = SharedValue(
// initial value
value: 0,
);

void main() {
runApp(
// Don't forget this bit of initialization code!
SharedValue.wrapApp(
MyApp(),
),
);
}
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2. Use
Unlike other state management solutions, SharedValue works everywhere you'd expect dart code to work, even without
a BuildContext.
void main() {
// Read [counter]
print(counter.$);

// Update [counter]
counter.$ += 1;
}

// Use [counter] in widgets, and let SharedValue do the rest.
Widget build(BuildContext context) {
// The .of(context) bit makes this widget rebuild automatically
int counterValue = counter.of(context);

return Text("Counter: $counterValue");
}
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3. Persist
// provide a shared_prefences key
final SharedValue<int> counter = SharedValue(
// disk storage key for shared_preferences (optional)
key: "counter",

// autosave to shared prefs when value changes (optional)
autosave: true,
);

void main() async {
// Load [counter]'s value from shared preferences
await counter.load();

// Store [counter]'s value to shared preferences (enabling `autosave` does this automatically)
await counter.store();
}
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Efficiency #
Shared value is smart enough to only rebuild the widget that subscribes to updates using .of(context), no more, no
less.