Reactive state db #

Description #

This package can be used to manage the state like a database.

Example usage #

import 'package:reactive_state_db/schema.dart';
import 'dart:async';

class Person {
  String name;
  int age;
  bool loading = false;

  Person(this.name, this.age, bool? loading) {
    this.loading = loading ?? this.loading;
  }
  @override
  String toString() {
    return '$name $age $loading';
  }

  Person copyWith({String? name, int? age, bool? loading}) {
    return Person(
      name ?? this.name,
      age ?? this.age,
      loading ?? this.loading,
    );
  }
}

Future<void> waitThreeSeconds() async {
  await Future.delayed(Duration(seconds: 3));
}

void start() async {
  final personStore = SchemaClass<Person>();

  personStore.add(Person('Alice', 25, false));

  personStore.get((person) => person.name == 'Alice').listen((person) {
    print(
        '1: Name: ${person?.name} | Age: ${person?.age} | loading: ${person?.loading}');
  });

  personStore.get((person) => person.age >= 30).listen((person) {
    print(
        '2: Name: ${person?.name} | Age: ${person?.age} | loading: ${person?.loading}');
  });

  personStore.setBeforeUpdate((newValue, setIntermediateState) async {
    setIntermediateState(newValue.copyWith(loading: true));
    await waitThreeSeconds();
  });
  personStore.setBeforeAdd((newValue) async {
    await waitThreeSeconds();
  });
  personStore.setBeforeRemove((newValue) async {
    print("Removing following: $newValue");
    await waitThreeSeconds();
    print("Removed following: $newValue");
  });

  waitThreeSeconds().then((_) {
    personStore.update(
        (person) => person.name == 'Alice', Person('Alice', 26, false));
    waitThreeSeconds().then((_) {
      personStore.update(
          (person) => person.name == 'Alice', Person('Alice', 27, false));
      waitThreeSeconds().then((_) {
        personStore.update(
            (person) => person.name == 'Bob', Person('Bob', 31, false));
        waitThreeSeconds().then(
            (_) => {personStore.remove((person) => person.name == 'Alice')});
      });
    });
  });

  personStore.add(Person('Bob', 30, false));
}

void main(List<String> arguments) async {
  start();
}