Optionaloptions: ObserverOptionsoptional parameters to customize the creation
import Observers from "apprt-core/Observers";
import { Evented } from "apprt-core/Events";
const eventSource = new Evented();
const observers = Observers();
// track connection to eventSource
observers.add(eventSource.on("event", ()=>{ ... }));
// if the connection needs to be cleaned call
observers.clean();
const eventSourceA = new Evented();
const eventSourceB = new Evented();
const observers = Observers();
// track connection to eventSourceA, but in group "a"
observers.group("a").add(eventSourceA.on("event", ()=>{ ... }));
// track connection to eventSourceB, but in group "b"
observers.group("b").add(eventSourceB.on("event", ()=>{ ... }));
// if "a" is not longer required
observers.group("a").clean();
// if "b" is not longer required (shows alternative)
observers.clean("b");
// if none of the connections are required anymore clean all
observers.clean();
// The bind/rebind functionality helps to encapsulate the code to connect to an observable.
// When the observable target changes a simple call to 'bind'
// rexecutes the connection code and clears the old connection.
import createObservers, { Observers } from "apprt-core/Observers";
import { Evented } from "apprt-core/Events";
interface CustomEvents {
"changed": boolean
}
class Controller {
private observers: Observers | undefined;
private events: any[] = [];
constructor() {
this.events = [];
this.observers = createObservers({
// rebind is executed if Observers.bind is called, and used to reconnect to a new source instance
rebind: (observers, source) => {
const eventSource = source as Evented<CustomEvents>;
observers.add(eventSource.on("change", (evt) => {
this.events.push(evt);
}));
}
});
}
connect(eventSource: Evented<CustomEvents>) {
// observe new event source
this.observers!.bind(eventSource);
}
disconnect() {
// disconnect from event source
this.observers!.clean();
}
}
Observers encapsulates a collection of connections to event emitters, like Evented, Mutable, Watches and the like. It therefor helps you to manage multiple event connections by grouping them - e.g. for cleaning all connections at once.