ng2-mobx

ng2-mobx

MobX connector for Angular 2

If you're looking for the Angular 1 version version, it's here

MobX is a modern reactive state management library.

This simple library connects MobX to Angular 2 components.

Why use MobX

The advantages of MobX are:

• Normalized - MobX lets you define computed values that are based on the minimal state
• Reactivity - MobX Automatically figures out when to re-invoke subscribers according to which observables they use. This allows for extremely performant applications
• Plain objects - Use plain objects and classes with MobX decorators, or even observe existing objects (from external sources for example)
• MobX is being used heavily in the community (mainly with React)

Read more about MobX

Why use this library

1. The library allows you to automatically observe all the observables that your component uses
2. You can also use it together with OnPush strategy, to incredibly high performance
3. It disposes of all the observers when the component is destroyed
4. It gives you powerful debugging tools

Usage

Install:

$ npm install --save ng2-mobx

Import the Ng2MobxModule:

import { Ng2MobxModule } from 'ng2-mobx';

@NgModule({
    imports: [..., Ng2MobxModule]
})
export class MyModule {}

autorun

Use *mobxAutorun directive in your template:

import {store} from './store/counter';

@Component({
  changeDetection: ChangeDetectionStrategy.OnPush,
  template: `
    <div *mobxAutorun>
      {{ store.value }} - {{ store.computedValue }}
      <button (click)="store.action">Action</button>
    </div>
  `
})
export class AppComponent {
    store = store;
}

The directive will observe all the observables that your component uses, and will automatically run the change detection whenever there's a change.

Use it together with onPush to gain maximum performance.

autorunSync

The same as autorun, except it runs synchronously.

reaction

Aside from autorun, MobX allows you to react to specific data changes.

Usage:

@Component({
  changeDetection: ChangeDetectionStrategy.OnPush,
  template: `<div *mobxReaction="getParity.bind(this)">
    {{ parity }}
  </div>`
})
class AppComponent {
  getParity() {
    return this.parity = store.counter % 2 ? 'Odd' : 'Even';
  }
}

The callback function will automatically re-run whenever any observable that it uses changes. Change Detection will run automatically whenever the return value of callback changes. If you don't return anything, change detection will not run.

In this example, the parity property will be updated according to counter, and change detection will run only when the parity changes.

Injectable stores

You can easily make your stores injectable:

@Injectable()
class Store {
  @observable value;
  @action doSomething() { ... }
}

Debugging MobX

ng2-mobx comes with a handy debug tool. to turn on / off the debug tool, open developer tools' console, and run:

ng2MobxDebug(true) // turn on
ng2MobxDebug(false) // turn off

Then you can hover over the components that use mobx directives, and you will have a small box to click on to console.log the dependencies of that component. Also, every action that happens in mobx will be console.logged in a nice way.

Examples

See the example folder, specifically these files:
/example/todos/src/app/stores/todos.ts
/example/todos/src/app/app.component.ts

To run the examples, clone this repo and run:

$ npm install -g angular-cli
$ cd example/*
$ npm install
$ ng serve