IndexedDB / PouchDB Blobs на iPad, Safari 11.3.1

Question

У меня есть угловое приложение 5.2.9 PWA, которое хранит данные локально в IndexedDB через PouchDB для автономного использования.Это приложение хранит фотографии в виде BLOB-объектов внутри документа.Я не использую вложения.Это работает в браузерах Chrome & Edge и Andriod, но Blob не хранится и не загружается должным образом на iPad.IPad работает под управлением Safari 11.3.1.Когда фотографии сделаны, они отображаются в моей галерее просто отлично.После сохранения и получения через PouchDB я получаю BLOB-объект нулевого размера.Мне не хватает определенных настроек или настроек Safari / iPad?

import { Component, OnInit, Inject } from '@angular/core';
import { Observable, BehaviorSubject } from 'rxjs';
import { MatDialog, MatDialogRef } from '@angular/material';
import { DomSanitizer, SafeResourceUrl, SafeUrl } from '@angular/platform-browser';
import { ConfigurationService } from '../../service/configuration.service';

import PouchDB from 'pouchdb';

import { Inspection } from '../../model/inspection';
import { PhotoDialogComponent } from './../photo-dialog/photo-dialog.component';
import { InspectionPhoto } from '../../model/inspection-photo';
import { zip } from 'rxjs/observable/zip';

@Component({
  selector: 'app-photo-gallery',
  templateUrl: './photo-gallery.component.html',
  styleUrls: ['./photo-gallery.component.css']
})
export class PhotoGalleryComponent implements OnInit {
  photoDialogRef: MatDialogRef<PhotoDialogComponent>;
  inspection: Inspection;

  photoList: BehaviorSubject<Array<InspectionPhoto>>;
  currentUrl: BehaviorSubject<SafeResourceUrl>;
  currentIndex: number;
  length: number;
  rotate: string;

  constructor(public config: ConfigurationService,
    public dialogRef: MatDialogRef<PhotoDialogComponent>,
    public dialog: MatDialog,
    public domSanitiser: DomSanitizer) {

    this.photoList = new BehaviorSubject<Array<InspectionPhoto>>(new Array<InspectionPhoto>());
    this.currentUrl = new BehaviorSubject<string>('');
    this.currentIndex = 0;
    this.length = 0;
    this.rotate = this.config.getRotateImages() ? "rotate90" : ""; 
  }

  ngOnInit() {
    let db = new PouchDB('inspection-photo');
    db.allDocs({include_docs: true})
    .then(result => {
      return Promise.all(result.rows.map(row => {
      let item = new InspectionPhoto();
      item = row.doc;
      item._id = row.id;
      item._rev = row.rev;
      return item;
      }));
    }).then(list => {
      this.length = list.length;
      this.currentIndex = 0; 
      this.photoList.next(list);
      if(list.length > 0) {
        this.getImageUrl(list[0]);
      }
    })
    .catch(err => {
      console.log('ngOnInit db error' + err);
      alert('ngOnInit db error' + err);
    });

  }

  public getImageUrl(inspectionPhoto: InspectionPhoto): void {
    if(inspectionPhoto == undefined 
      || inspectionPhoto.Photo == undefined){ 
      return; }

    // alert('blob size: ' + inspectionPhoto.Photo.size);

    let modified: Date = new Date();
    let f:File = new File([inspectionPhoto.Photo], 
      "image" + this.currentIndex + ".jpg", 
      {type: "image/jpeg", lastModified: modified.getUTCMilliseconds()}
    );

    // alert('file: ' 
    //   + ' name: ' + f.name
    //   + ' type: ' + f.type
    //   + ' size: ' + f.size
    // );

    let url: string;
    try {
      url = URL.createObjectURL(f, {oneTimeOnly: true}); //.substring(5);
    }
    catch (e) {
      alert('1:' + (<Error>e).message + (<Error>e).stack);
    }

    let sanitisedUrl: SafeResourceUrl;
    try{
      sanitisedUrl = this.domSanitiser.bypassSecurityTrustResourceUrl(url);
    }
    catch (e) {
      alert('2:' + (<Error>e).message);
    }

    try{
      this.currentUrl.next(sanitisedUrl);
    }
    catch (e) {
      alert('3:' + (<Error>e).message);
    }
}

  public onNext() {
    if (this.currentIndex >= this.length - 1) {
      this.currentIndex = 0;
    } else {
      this.currentIndex += 1;
    }
    this.photoList.subscribe(list => {
      // alert('image:' + this.currentIndex);
      this.getImageUrl(list[this.currentIndex]);
    });
  }

  public onPrevious() {
    if (this.currentIndex <= 0) {
      this.currentIndex = this.length - 1;
    } else {
      this.currentIndex -= 1;
    }
    this.photoList.subscribe(list => {
      // alert('image:' + this.currentIndex);
      this.getImageUrl(list[this.currentIndex]);
    });
  }

  OnNewPhoto(): void {
    this.photoDialogRef = this.dialog.open(PhotoDialogComponent, {
    });

    this.photoDialogRef.afterClosed().subscribe((result) => {
      if (result) {
        let inspectionPhoto = new InspectionPhoto();
        inspectionPhoto.InspectionId = this.inspection._id;
        inspectionPhoto.WorkOrderId = this.inspection.WorkOrderId;
        inspectionPhoto.TaskId = this.inspection.TaskId;
        inspectionPhoto.EquipmentId = this.inspection.EquipmentId;
        let db = new PouchDB('inspection-photo');
        let files: File[] = Array.from(this.photoDialogRef.componentInstance.files);
        files.forEach(f => {

          // alert('file: ' 
          //   + ' name: ' + f.name
          //   + ' type: ' + f.type
          //   + ' size: ' + f.size
          // );

          inspectionPhoto._id = this.config.uniqueID();
          inspectionPhoto.Photo = new Blob([f], {type: 'image/jpeg'});
          // alert('Blob size: ' + inspectionPhoto.Photo.size);

          db.put(inspectionPhoto)
            .then(result => {
              inspectionPhoto._id = result.id;
              inspectionPhoto._rev = result.rev;

              // alert('**** saved photo blob size:' + inspectionPhoto.Photo.size);

              this.photoList.subscribe(list => {
                list.push(inspectionPhoto);
                this.length = list.length;
                this.currentIndex = this.length - 1; 
              });
              this.getImageUrl(inspectionPhoto);
            })
            .catch(err => {
              console.log('OnNewPhoto db error ' + err);
              alert('OnNewPhoto db error ' + err);
            });
        });
      }
      this.photoDialogRef = null;
    });
  }

}