Basic ev manager

ev.alt.2.js

class App {
  constructor() {
    this._listeners = {};
  }
  ev(obj, listener) {
    return this._listeners[name](this, obj);
  }
  listener(name, func) {
    if(this._listeners[name]) {
      throw `${name} already exists`;
    }
    else {
      this._listeners[name] = func;
    }
  }
  listeners() {
    return Object.keys(this._listeners);
  }
}

const app = new App();

app.listener(
  'hello', 
  (app, obj) =>
    console.log([app, obj]))

app.ev('bingo gin', 'hello');

ev.alt.js

class App {
  ev(obj, listener) {
    return this.ev[listener](this, obj);
  }
}

const app = new App();

app.ev.hello = (app, obj) =>
    console.log([app, obj]);

ev('bingo gin', 'hello');

ev.js

function evManager(app){
    return function ev(obj, listener) {
        return ev[listener](app, obj);
    }
}

window.ev = evManager({hello:"world"});

ev.hello = (app, obj) =>
    console.log([app, obj]);

ev('bingo', 'hello');