DefineMap.toStreamFromEvent( eventName )

Creates a stream from an event that gets updated whenever the event is triggered.

import DefineList from "can-define/list/list";
import canDefineStreamKefir from "can-define-stream-kefir";

const PeopleList = DefineList.extend( {} );

canDefineStreamKefir( PeopleList );

const people = new PeopleList( [
    { first: "Justin", last: "Meyer" },
    { first: "Paula", last: "Strozak" }
] );

const stream = people.toStreamFromEvent( "length" ); // using eventName

stream.onValue( function( val ) {
    val; //-> 2, 3
} );

people.push( {
    first: "Obaid",
    last: "Ahmed"
} ); //-> stream.onValue -> 3