@ngxs-contrib/emitter

@ngxs-contrib/emitter

This package allows you to get rid of actions to make changes to the store. You're able to use decorators to register actions directly in your state, you should not create any actions in your project, as they don't give any profit, only bring extra boilerplate files.

Installation

To get started install this package from npm.

npm install @ngxs-contrib/emitter

# or with yarn
yarn add @ngxs-contrib/emitter

After installation - import the NgxsEmitPluginModule into your app.module.ts:

import { NgModule } from '@angular/core';
import { NgxsEmitPluginModule } from '@ngxs-contrib/emitter';

@NgModule({
    imports: [
        ...,
        NgxsEmitPluginModule.forRoot()
    ]
})
export class AppModule {}

Emitter

Emitter is just a single function that can be used to decorate static methods of your states, this will add extra static metadata.

import { State } from '@ngxs/store';
import { Emitter, EmitterAction } from '@ngxs-contrib/emitter';

export interface CounterStateModel {
    value: number;
}

@State<CounterStateModel>({
    name: 'counter',
    defaults: {
        value: 0
    }
})
export class CounterState {
    @Emitter()
    public static setValue({ setState }, { payload }: EmitterAction<number>) {
        setState({
            value: payload
        });
    }
}

PayloadEmitter

@PayloadEmitter is a decorator that will define getter for the decorated property. You will get an access to the emittable object.

import { Select } from '@ngxs/store';
import { PayloadEmitter, Emittable } from '@ngxs-contrib/emitter';

@Component({
    selector: 'app-counter',
    template: `
        <ng-container *ngIf="count$ | async as count">
            <h3>Count is {{ count.value }}</h3>
            <div class="add-counter">
                <button (click)="counterValue.emit(count.value + 1)">Increment (+1)</button>
                <button (click)="counterValue.emit(count.value - 1)">Decrement (-1)</button>
            </div>
        </ng-container>  
    `
})
export class CounterComponent {
    // Reads the name of the state from the state class
    @Select(CounterState)
    public count$: Observable<number>;

    // Use in components to emit asynchronously payload
    @PayloadEmitter(CounterState.setValue)
    public counterValue: Emittable<number>;
}

Dependency Injection with @Emitter decorator

If you want to subscribe to the changes, you can easily do this. You can also use the action method in store. Also you can access the dependencies with the injector.

import { State } from '@ngxs/store';
import { Injector } from '@angular/core';
import { Emitter } from '@ngxs-contrib/emitter';

@State<CounterStateModel>({
   name: 'counter',
   defaults: {
       value: 0
   }
})
export class CounterState {
   public static api: ApiService;

   constructor(injector: Injector) {
       CounterState.api = injector.get<ApiService>(ApiService);
   }

   @Emitter()
   public static loadData({ setState }) {
       // Some heavy function
       return this.api.getValueFromServer().pipe(
           tap((value: number) => setState({ value }))
       );
   }
}

import { Select } from '@ngxs/store';
import { PayloadEmitter, Emittable } from '@ngxs-contrib/emitter';

@Component({ 
   selector: 'app-count'
   template: `
       <ng-container *ngIf="count$ | async as count">
           <h3>
               Count is {{ count.value }}
               <span *ngIf="isLoading">loading...</span>
           </h3>
           <div class="add-counter">
               <button (click)="loadData()">Load data from server</button>
           </div>
       </ng-container>  
   `
})
export class CounterComponent {
   @Select(CounterState)
   public count$: Observable<CounterStateModel>;

   public isLoading = false;

   @PayloadEmitter(CounterState.loadData)
   public loadData: Emittable<void>;
 
   public loadCountData() {
       this.isLoading = true;

       this.loadData.emit().subscribe(() => {
           this.isLoading = false;
       });
   }
}