javascript - Selects' events in Angular2 -

please, can me? supposed easy, can't find solution. there form 2 selects. when #select1 changes, #select2 needs show data according value of #select1. example, cities of each state. kind of :

//html  <select (change)="select2.getcities($event)" ng-control="userstate">     <option *ng-for="#state of states" [value]="state">{{state}}</option> </select>  <select #select2 ng-control="usercity">     <option *ng-for="#city of cities" [value]="city">{{city}}</option> </select>  //the component @component({ selector: 'user-management', appinjector: [formbuilder] }); @view({ templateurl: 'user-management.html', directives: [ngfor] }); export class usermanagement {     constructor(fb: formbuilder){         this.userform = fb.group({             userstate: [],             usercity: []         });         this.states = ['new york', 'pennsylvania'];         this.cities = {'new york': ['albany', 'buffalo'], 'pennsylvania':['pittsburgh', 'philadelphia']};     }     getcities($event){         return this.cities[$event.target.value];     } } 

this, of course, doesn't work. please, know how should done? it's in alpha28.

great! found out how make work! :) thing missing, form model passed event. should this:

<form [ng-form-model]="userform"> <select (change)="select2.getcities($event, userform)" ng-control="userstate">     <option *ng-for="#state of states" [value]="state">{{state}}</option> </select>