DefineMap.toStreamFromEvent( eventName )

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

var DefineList = require('can-define/list/list');
var canDefineStreamKefir = require("can-define-stream-kefir");

var PeopleList = DefineList.extend({});

canDefineStreamKefir(PeopleList);

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

var stream = people.toStreamFromEvent('length'); // using eventName

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

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