Problem with ifram PDF tag in ionic 2

hi every one , i have a problem

When you open a this page the settimeout function run to add the points to watch After 60 seconds,
i dont know why the PDF will be reloaded again, what is the problem?

<ion-content padding>
  <iframe [src]='photoURL()' width="100%" height="100%" frameborder="0">
        </iframe>
</ion-content>
import {Component,ViewChild} from '@angular/core';
import { Events,Platform,NavController,NavParams,AlertController,App,Slides} from 'ionic-angular';
import { Users } from './../../providers/users';//
import { DomSanitizer} from '@angular/platform-browser';
import {TranslateService} from '@ngx-translate/core';
import { AppUtilFunctions } from './../../app/appglobal/app.utilfuns';//
@Component({
  selector: 'page-pdf-viewer',
  templateUrl: 'pdf-viewer.html',
})
export class PdfViewerPage {
     link :any;
     title:any;
     publication_id:any
     user_id:any
     timeOut:any;
     
  constructor(public navCtrl: NavController,
    private appUtils: AppUtilFunctions,
    public navParams: NavParams,
    private translateService: TranslateService,
    private sanitizer: DomSanitizer,
     private userpage: Users ) {

      this.timeOut =  setTimeout(() => this.addPoints(), 10000); 
               console.log(this.timeOut);
  }

  ionViewDidLoad() {
    this.link    = this.navParams.get("link");  
    this.title    = this.navParams.get("title"); 
    this.publication_id    = this.navParams.get("publication_id"); 
    this.user_id    = this.navParams.get("user_id"); 
    console.log( this.link,'this.link');
  }
 photoURL(){
   
     return this.sanitizer.bypassSecurityTrustResourceUrl(this.link);
  }
addPoints(){
if(this.user_id ){
   let getPublication={publication_id:this.publication_id,user_id:this.user_id};
   this.userpage.addPoints(getPublication)
     .subscribe((res) => {
        if (res.data=="success") {          
      // console.log('video ended successsfuuulllly and we add points');
         }
       else if (res.errors =='Error'){
        //  console.log('video ended successsfuuulllly but there is error when we add points')
           }

         },err => {
          
           this.translateService.get('CheckConnection').subscribe(
           value => {
             // value is our translated string
           this.appUtils.AppToast(value);
                 })   
          //alert('err')
          if (err.error instanceof Error) {
         // alert('client side error');
          } else {
         // alert('server side error');
          }    
      })
    }
 }
  ionViewDidLeave() {
    //Stop refresh
     clearTimeout(this.timeOut);
   }
}

providers here

addPoints(Da){
    let data = JSON.stringify(Object.assign(Da));
    return this.http.post(this.api.API_URL+'points.php?action=addPoints', data).map(res=>res.json());
}