Evt.from<T>(...)

Creates an Evt that post events of a specific type coming from other API that emmits events.

Returns

Evt<T> will post every time the emitter emits

Parameters

Ctx Optional, Allows detaching the handlers attached to the source emitter.

emitter: Any of the following,

  • DOM EventTarget

  • Node.js EventEmitter

  • JQuery-like event target

  • RxJS Subject

  • An Array, NodeList or HTMLCollection of many of these.

  • A promise

Depending of the API the type argument will be inferred or not.

name: The event name of interest, being emitted by the target.

Example

From EventEmitter

import { Evt } from "evt";
import { EventEmitter } from "events";
const ctx= Evt.newCtx();
const ee= new EventEmitter();
const evtText= Evt.from<string>(ctx, ee, "text");
evtText.attach(text=> console.log(text));
evtText.post("Foo bar");//Prints "Foo bar";
ctx.done();
console.log(ee.listenerCount("text"));//Prints "0"

****Run the example****

With RxJS Subject

import { Evt } from "evt";
import { Subject } from "rxjs";
const ctx= Evt.newCtx();
const subject = new Subject<string>();
const evtText = Evt.from(ctx, subject); //The type argument is inferred.
evtText.attach(text=> console.log(text));
subject.next("Foo bar"); //Prints "Foo bar"
ctx.done();
subject.next("Foo bar"); //Prints nothing

****Run the example****

With DOM EventTarget

import { Evt } from "evt";
Evt.from(document, "click").attach(()=> console.log("Clicked!"));

****Run the example****

With JQuery-like event target

import { Evt } from "evt";
Evt.from([
$("#btnA"),
$("#btnB"),
$("#btnC")
], "click").attach(()=> console.log("Clicked!"));