angular - IONIC 2 native Network.onDisconnect() running code twice -

i working ionic 2 rc1 , using sublime text editor. need check if network connection connected or not. purpose using ionic native network purpose. facing problem network.ondisconnect() observable. have edited initializeapp() method in check network connection , show alert if connection got disconnected. have following code written in app.component.ts

  showalert(title, msg) {     let alert = this.alertctrl.create({       title: title,       subtitle: msg,       buttons: ['ok']     });     alert.present();   }    initializeapp() {     this.platform.ready().then(() => {       // okay, platform ready , our plugins available.       // here can higher level native things might need.       let disconnectsubscription = network.ondisconnect().subscribe(() => {         this.showalert("error", "no internet connection");       });       statusbar.styledefault();     });   } 

the problem facing alert shown twice if application disconnected internet. have found similar issue in post got unanswered. on regard appreciated. in advance !

in order avoid that, can filter events, , when state changes online offline, or offline online (and not every time event being fired plugin). can create service handle logic this:

import { injectable } '@angular/core'; import { network } 'ionic-native'; import { events } 'ionic-angular';  export enum connectionstatusenum {     online,     offline }  @injectable() export class networkservice {      private previousstatus;      constructor(private eventctrl: events) {         this.previousstatus = connectionstatusenum.online;     }      public initializenetworkevents(): void {         network.ondisconnect().subscribe(() => {             if (this.previousstatus === connectionstatusenum.online) {                 this.eventctrl.publish('network:offline');             }             this.previousstatus = connectionstatusenum.offline;         });         network.onconnect().subscribe(() => {             if (this.previousstatus === connectionstatusenum.offline) {                 this.eventctrl.publish('network:online');             }             this.previousstatus = connectionstatusenum.online;         });     } } 

so our custom events (network:offline , network:online) fired when connection changes (fixing scenario when multiple online or offline events fired plugin when connection state hasn't changed @ all).

then, in app.component file need subscribe our custom events:

// offline event this.eventctrl.subscribe('network:offline', () => {   // ...             });  // online event this.eventctrl.subscribe('network:online', () => {   // ...             });