called function does not wrk properly

I am using ionic2 with firebase.

Here is my Component..

import { Component } from '@angular/core'; import { NavController, NavParams ,Platform} from 'ionic-angular'; import { LocalNotifications,Toast} from 'ionic-native'; import { FirebaseAuth, AuthProviders, AuthMethods} from 'angularfire2'; import { Authservice } from '../../providers/authservice'; import { AlbumPage } from '../../pages/album/album'; import { MycomplaintsPage } from '../../pages/mycomplaints/mycomplaints'; import { NeighboursPage } from '../../pages/neighbours/neighbours'; import { NotificationsPage } from '../../pages/notifications/notifications'; import { ChatlistPage } from '../../pages/chatlist/chatlist'; import { TabsPage } from '../../pages/tabs/tabs'; import { CircularPage } from '../../pages/circular/circular'; import { EventPage } from '../../pages/event/event'; import { SettingsPage } from '../../pages/settings/settings'; import { VisitorsPage } from '../../pages/visitors/visitors'; import { AlarmPage } from '../../pages/alarm/alarm'; import { AlarmdetailsPage } from '.././alarmdetails/alarmdetails'; import { PropertyPage } from '../../pages/property/property';

import { FormBuilder } from '@angular/forms'; import { AngularFire } from 'angularfire2'; declare var Media:any; declare var window: any; /* Generated class for the Dashboard page.

See http://ionicframework.com/docs/v2/components/#navigation for more info on Ionic pages and navigation. */ @Component({ selector: 'page-dashboard', templateUrl: 'dashboard.html' }) export class DashboardPage { EMERGENCY=[]; ApartID; USERID; audio; audioplaying;

constructor(public af:AngularFire,public fb:FormBuilder,public platform: Platform,public authservice:Authservice,public navCtrl: NavController, public navParams: NavParams, public auth: FirebaseAuth) {

this.platform.ready().then(() => {

 var url='https://firebasestorage.googleapis.com/v0/b/apartments-ea9e5.appspot.com/o/Loud-Ringtone-11-Emergency-Alert.mp3?alt=media&token=7d67b437-e96b-484e-bd97-008106a06dcb';
 this.audio = new Media(url,

    // success callback

    function () { console.log("playAudio():Audio Success"); },

    // error callback

    function (err) { console.log("playAudio():Audio Error: " + err); },

    function(statusCallback){console.log("Status"+statusCallback)
     this.audioplaying = statusCallback;
     localStorage.setItem("audioplaying",this.audioplaying);
  }

);

})

}

ionViewDidLoad() { console.log('ionViewDidLoad DashboardPage'); this.Backroundnotifications(); }

albums() { this.navCtrl.push(AlbumPage); } complaints() { this.navCtrl.push(MycomplaintsPage); } myNeighbours() { this.navCtrl.push(NeighboursPage); } notification() { this.navCtrl.push(NotificationsPage); } chats() { this.navCtrl.push(ChatlistPage); } directory() { this.navCtrl.push(TabsPage);
} circular() { this.navCtrl.push(CircularPage); } eventbooking() { this.navCtrl.push(EventPage); } settings() { this.navCtrl.push(SettingsPage); } visitors() { this.navCtrl.push(VisitorsPage); } propertyPage() { this.navCtrl.push(PropertyPage); } alarmPage() { this.navCtrl.push(AlarmPage); }

//receive notifications

schedule(a) { console.log("receive Notification") var val=a; var t:any=a.MSG; var time:any=a.SEND_TIME; LocalNotifications.schedule({ title: "Smart Premises", text: t, at: time, sound:this.playSelectedTrack(), });

}

playSelectedTrack():any{ console.log("audio play"); this.audio.play();

}

Backroundnotifications() { //Get Current UserID

  var roleid1=localStorage.getItem('Roleid');
  this.authservice.getcurrentuserID().subscribe(
    data=>{
      console.log(data);
      this.ApartID=data[0].APART_ID;
      this.USERID=data[0].USER_ID;

       if(roleid1 === '2' || roleid1 === '5')
    {
      this.authservice.GetEmergencytype(this.ApartID).subscribe(d=>{
          var EM=d;
          this.EMERGENCY=EM.filter(a=>a.FROM.toString() != this.USERID.toString());
          console.log("this.EMERGENCY");
          console.log(this.EMERGENCY);
          if(this.EMERGENCY[0].STATUS == 'ON')
          {
            console.log("this");
            console.log(this.EMERGENCY[0]);
          }   
          })

        }
    })

}

called this Backroundnotifications() in constructor.It's work properly at first time.again goto another page after click dashboardpage .this function called many times.

I mean consoled the value of this.EMERGENCY many times.

any other user push firebase collections.I need get updated value only.

How i am able to do this.

Kindly help me,

angular / angularfire

called function does not wrk properly #884