MiniRx Store 5

MiniRx Store 5 has been released (2023-04-17)!

What's new?

Component Store:
- Manage state independently of the global state object (which is used by Store and Feature Store)
- Component Store and Feature Store share the same API (setState, select, effect...)
- Component Store is perfect for managing smaller and local state (most times that is Component state)
- You can use most of the MiniRx extensions: Logger Extension, Undo Extension and Immutable Extension
- Extensions can be configured globally or individually for each Component Store instance
Tree-shakable: even more lightweight!
Lazy state initialisation with setInitialState
setState accepts also an Observable: use an Observable to update state
createFeatureSelector has been deprecated. Use now createFeatureStateSelector which is more in line with createComponentStateSelector

Read more in the CHANGELOG about the changes and the very few BREAKING CHANGES.

Angular Integration (mini-rx-store-ng)

ComponentStoreModule: Configure ComponentStore extensions globally with the forRoot static method
BREAKING CHANGE: StoreDevtoolsModule has been removed. You can use now the normal ReduxDevtoolsExtension from mini-rx-store with StoreModule.forRoot.

Read more in the CHANGELOG of the Angular Integration.

Installation

npm i mini-rx-store

Install the Angular Integration if you are using Angular:

npm i mini-rx-store-ng

The Angular Integration requires now Angular@12.

MiniRx Store

MiniRx Store provides Reactive State Management, powered by RxJS. It is a highly flexible solution and scales with your state management needs:

Manage global state at large scale with the Store (Redux) API
Manage global state with a minimum of boilerplate using Feature Stores
Manage local component state with Component Stores

MiniRx always tries to find the sweet spot between powerful, simple and lightweight.

🤓 Learn more about MiniRx on the docs site

🚀 See MiniRx in action:

Angular Demo (source code)
Svelte Demo (source code)

What's Included

RxJS powered global state management
State and actions are exposed as RxJS Observables
Store (Redux):
- Actions
- Reducers
- Meta Reducers
- Memoized Selectors
- Effects
- mapResponse operator: handle the side effect response in Effects
- Support for ts-action: Create actions and reducers more efficiently
Feature Store: Manage feature state directly with a minimum of boilerplate:
- setState() update the feature state
- setInitialState() initialize state lazily
- select() select state from the feature state object as RxJS Observable
- effect() run side effects like API calls and update feature state
- undo() easily undo setState actions (requires the UndoExtension)
- destroy() remove the feature state from the global state object
- tapResponse operator: handle the side effect response in Feature Store effect
Component Store: Manage state locally:
- Component Store is perfect for local component state
- Component Store has the same simple API as Feature Store (setState, select, ...)
- Component Store state is independent of the global state object
- Component Store is destroyable
Extensions:
- Redux DevTools Extension: Inspect global state with the Redux DevTools
- Immutable Extension: Enforce state immutability
- Undo Extension: Undo dispatched actions
- Logger Extension: console.log the current action and updated state
Framework-agnostic: MiniRx works with any frontend project built with JavaScript or TypeScript (Angular, Svelte, React, Vue, or anything else)
TypeScript support: The MiniRx API comes with TypeScript type definitions
Angular Integration: Use MiniRx Store the Angular way:
- Configure the Store with StoreModule.forRoot()
- Add feature state with StoreModule.forFeature()
- Inject Store and Actions

Key Concepts

State and actions are exposed as RxJS Observables
Single source of truth: The Store holds a single object which represents the global application state
The global state has a flat hierarchy and is divided into "feature states" (also called "slices" in Redux world)
For each "feature state" we can decide to use the Store (Redux) API with actions and reducers or the simplified FeatureStore API
Store and FeatureStore are different APIs for one and the same Redux Store
Use ComponentStore to manage state which is independent of the global state object
State is read-only (immutable) and can only be changed by dispatching actions (Redux API) or by using setState (Feature Store / Component Store)

Installation

Install from the NPM repository using npm:

npm install mini-rx-store

Install the RxJS peer dependency:

npm install rxjs

Basic Tutorial

Let's dive into some code to see MiniRx in action. You can play with the tutorial code on StackBlitz.

Store (Redux)

MiniRx supports the classic Redux API with registering reducers and dispatching actions. Observable state can be selected with memoized selectors.

import {
  Action,
  Store,
  configureStore,
  createFeatureStateSelector,
  createSelector
} from 'mini-rx-store';
import { Observable } from 'rxjs';

// 1.) State interface
interface CounterState {
  count: number;
}

// 2.) Initial state
const counterInitialState: CounterState = {
  count: 1
};

// 3.) Reducer
function counterReducer(
  state: CounterState = counterInitialState,
  action: Action
): CounterState {
  switch (action.type) {
    case 'inc':
      return {
        ...state,
        count: state.count + 1
      };
    default:
      return state;
  }
}

// 4.) Get hold of the store instance and register root reducers
const store: Store = configureStore({
  reducers: {
    counter: counterReducer
  }
});

// 5.) Create memoized selectors
const getCounterFeatureState = createFeatureStateSelector<CounterState>('counter');
const getCount = createSelector(
  getCounterFeatureState,
  state => state.count
);

// 6.) Select state as RxJS Observable
const count$: Observable<number> = store.select(getCount);
count$.subscribe(count => console.log('count:', count));
// OUTPUT: count: 1

// 7.) Dispatch an action
store.dispatch({ type: 'inc' });
// OUTPUT: count: 2

Read more in the MiniRx docs: Store (Redux)

Feature Store

With MiniRx Feature Stores we can manage feature state directly with a minimum of boilerplate.

import { FeatureStore } from 'mini-rx-store';
import { Observable } from 'rxjs';

// State interface
interface CounterState {
  count: number;
}

// Initial state
const counterInitialState: CounterState = {
  count: 11
};

// Extend FeatureStore and pass the State interface
export class CounterFeatureStore extends FeatureStore<CounterState> {
  // Select state as RxJS Observable
  count$: Observable<number> = this.select(state => state.count);

  constructor() {
    // Call super with the feature key and the initial state
    super('counterFs', counterInitialState);
  }

  // Update state with `setState`
  inc() {
    this.setState(state => ({ count: state.count + 1 }));
  }
}

Use the "CounterFeatureStore" like this:

import { CounterFeatureStore } from "./counter-feature-store";

const counterFs = new CounterFeatureStore();
counterFs.count$.subscribe(count => console.log('count:', count));
// OUTPUT: count: 11

counterFs.inc();
// OUTPUT: count: 12

ℹ️ The state of a Feature Store becomes part of the global state

Every new Feature Store will show up in the global state with the corresponding feature key (e.g. 'counterFs'):

store.select(state => state).subscribe(console.log);
// OUTPUT: {"counter":{"count":2},"counterFs":{"count":12}}

Read more in the MiniRx docs: Feature Store

Component Store

Manage state locally and independently of the global state object. Component Store has the identical API as Feature Store.

import { ComponentStore } from 'mini-rx-store';
import { Observable } from 'rxjs';

// State interface
interface CounterState {
  count: number;
}

// Initial state
const counterInitialState: CounterState = {
  count: 111,
};

// Extend ComponentStore and pass the State interface
export class CounterComponentStore extends ComponentStore<CounterState> {
  // Select state as RxJS Observable
  count$: Observable<number> = this.select((state) => state.count);

  constructor() {
    // Call super with the initial state
    super(counterInitialState);
  }

  // Update state with `setState`
  inc() {
    this.setState((state) => ({ count: state.count + 1 }));
  }
}

Use the "CounterComponentStore" like this:

const counterCs = new CounterComponentStore();
counterCs.count$.subscribe(count => console.log('count:', count));
// OUTPUT: count: 111

counterCs.inc();
// OUTPUT: count: 112