Angular2 (2.0.0-alpha.44) pass parameters from your own component event (look at template for parent)

Child.ts

import {Component} from 'angular2/angular2'

@Component({
  selector: 'child',
  template: '<div (click)='passNumber.next(num)'/>',

})
export default class Login {
  public num: number = 1
  @Output() passNumber = new EventEmitter()
}

Parent.ts

import {Component} from 'angular2/angular2'
import Child from './child.ts'

// $event param is the key here — without it nothing is passed to callback
@Component({
  selector: 'parent',
  template: '<child (pass-number)='callback($event)'/>',
  directives: [Child],

})
export default class Login {
  public callback: Function

  constructor(){
    this.callback = num => console.log(num)
  }
}