@yadah/domain-listener v0.2.0

Yadah Listener mixin

A mixin for Yadah Domain classes adding the registerListeners() method. It provides a standardised way for Domain classes to register event handlers.

registerListeners()

Hook for derived classes to register event listeners.

registerListeners() is called during the boot() lifecycle method so access to other domains and subsystems is available.

registerListeners() should return synchronously.

import ListenerMixin from "@yadah/domain-listener";
import { Domain } from "@yadah/data-manager";
import { pipe } from "@yadah/mixin";

class MyDomain extends pipe(Domain, ListenerMixin) {
  registerListeners() {
    // ensure superclass event listeners are registered
    super.registerListeners();

    // listen for 'hello' events
    this.on("hello", (name) => this.hello(name));
  }

  hello(name) {
    console.log(`Hello ${name}`);
  }
}

// after domain boot
dataManager.domains.MyDomain.emit("hello", "world"); // logs "Hello world"

It is common to listen to events from other domains:

registerListeners() {
    // ensure superclass event listeners are registered
  super.registerListeners();

  // listen for 'hello' events
  this.on("hello", (name) => this.hello(name));

  // listen for 'hola' events on another domain class
  const { OtherDomain } = this.domains;
  OtherDomain.on("hola", (name) => this.hello(`${name} (OtherDomain)`));
}

dataManager.domains.OtherDomain.emit("hola", "mundo"); // logs "Hello mundo (OtherDomain)"