ngrx-event-bus

Angular and RxJs event bus with Mediator Pattern

Usage no npm install needed!

<script type="module">
  import ngrxEventBus from 'https://cdn.skypack.dev/ngrx-event-bus';
</script>

README

NgRxEventBus

Meditor Pattern based EventBus service mechanism as Angular service using RxJs. You can publish events to a bus and any component can subscribe the events. Subscribers of your event (event identification is being done using event-name as string).

npm npm

This library was generated with Angular CLI version 8.3.29.

Live Demo

How to consume

To get more help on the Angular CLI use ng help or go check out the Angular CLI README.

  1. Install npm package ngrx-event-bus.

    npm i ngrx-event-bus --save
    
  2. Import Module

import {NgRxEventBusModule} from 'ngrx-event-bus';

@NgModule({
    ...
  imports:[NgRxEventBusModule ],
    ...
})

  1. Register the events if you'd like to support events
    //create Event class and inherit by IEvent
    export class BusEvents implements IEvent {
        public static TitleChangeEvent: string = "TitleChangeEvent";
    }

    import {NgRxEventBusService,EmitEvent, IEvent} from 'ngrx-event-bus';
    export class AppComponent  {
        constructor(private eventBus: NgRxEventBusService) { 
          //Optional event registeration
          //default value is optional and if sent it will register event with BehaviorSubject
          //registerEvent will help when you are emitting event before someone subscribing to it
          this.eventBus.registerEvent(BusEvents.TitleChangeEvent,{title:"default title"});
        }
        title = "Demo";
        ngOnInit() {
            //Register Event Listner
            this.eventBus.on(BusEvents.TitleChangeEvent, (title: string) => {
                this.title = title;
            });
        }
    }
  1. Publish Event if you'd like some one to subscribe
    import { EmitEvent,NgRxEventBusService } from 'ngrx-event-bus';
    export class TitleComponent {
        constructor(private eventBus: NgRxEventBusService) { }
        textValue = '';
        onChangeTitle(title) {
            this.eventBus.emit(new EmitEvent(BusEvents.TitleChangeEvent, this.textValue));
        }
    }

What is new in 2.1.1?

With this release you can able to get First, Last and All values with your first subscription.

    this.eventBus.on(BusEvents.TitleChangeEvent, (title: string) => {
                this.title = title;
            },EmitRecord.First);

            this.eventBus.on(BusEvents.TitleChangeEvent, (title: string) => {
                this.title = title;
            },EmitRecord.Last);

            this.eventBus.on(BusEvents.TitleChangeEvent, (title: string[]) => {
                this.title = string.join(title,',');
            },EmitRecord.All);
    /*
        export enum EmitRecord {
              First = 1,
              Last = 2,
              All = 3
        }
    */

Thumb Rules

  1. Event class should implements by IEvent.
  2. Declare static string under Event Class.