Variable dinamyc value not work with popOver & Event subcribe

export class popOverControlPage{
ps : any;
aa : any;

constructor(public vewCtrl : ViewController, public events : Events, public toastCtrl : ToastController){ 
this.aa="Yesh ...";
this.events.subscribe("info", (response) =>{

   this.aa = response["fdate"];
   	});

   	this.ps = this.aa; <--// not Works , not found get dinamyc value. this output : "Yesh ..."
	}

}

Or complite source

@Component({
 	template : `<ion-list>
 	<ion-list-header>Filter Info</ion-list-header>
 	<ion-item>{{fdate}}</ion-item>
 	<ion-item>{{tdate}}</ion-item>
 	</ion-list>
 	`
 })
 export class popOverControlPage{
 	myObject : any;
 	myKeys : any;
 	fdate : string;
 	tdate : any;

 	constructor(public vewCtrl : ViewController, public events : Events, public toastCtrl : ToastController){ 
 	
 		this.events.subscribe("info", (response) =>{
 			this.getData(response)
 			
 		});

 	}
 	ionViewDidLoad(){

 	}
 	 getData(data){
 		this.myObject = JSON.parse(JSON.stringify(data));
 		this.myKeys = Object.keys(this.myObject).map(key => ({id : key, value : this.myObject[key]}));
 		this.fdate = this.myKeys[0].value;
 		this.tdate = this.myKeys[1].value

 	 }


 	close(){
 		this.vewCtrl.dismiss();
 	}
 }

fdate & tdate not work, is null value.