@ushiboy/observable-store v0.1.0

Observable Store

The observable-store notify when own state changed.

Example

Simple Example

import createObservableStore from '@ushiboy/observable-store';

const store = createObservableStore({
  count: 0
});

const state = store.state;

const observer1 = () => {
  console.log(`change: count:${state.count}`);
};
const observer2 = () => {
  console.log(`(observer 2) change: count:${state.count}`);
};

store.observe(observer1);
store.observe(observer2);

console.log(`count: ${state.count}`); // count: 0;

store.assign({
  count: state.count + 1
});
console.log(`count: ${state.count}`); // count: 1;

try {
  state.count = state.count + 1;  // throw Error
} catch (e) {
  console.log(`${e}`); // Error: Should use assign
}
console.log(`count: ${state.count}`); // count: 1;

store.unobserve(observer2);

store.assign({
  count: state.count + 1
});
console.log(`count: ${state.count}`); // count: 2;

Example Application

• counter: Simple counter application.
• counter-ext: React counter application (with server side rendering).

API

createObservableStore<T>(initialState: T): Store<T>

Creates an instance of observable store.

const store = createObservableStore({ users: [], organization: 'mycompany' });

Instance properties

store.state: T

Provides its own state.

console.log(store.state.organization); // -> 'mycompany'

store.state.organization = 'other'; // -> throw Error

Instance methods

store.assign(...sources: any): void

Updates its own state. Notify when the state changes.

store.assign({ users: ['user1', 'user2', 'user3'] }, { organization: 'newcompany' });

store.replace(sources: any): void

Force updates its own state and notify.

store.replace({ users: ['user1', 'user2', 'user3'] });

store.observe(o: (state: T) => void): void

Register an observer.

const observer = state => {
  console.log(store.state.users);
};
store.observe(observer);

store.unobserve(o: (state: T) => void): void

Unregister an observer.

const observer = state => {
  console.log(store.state.users);
};
store.unobserve(observer);

License

MIT