AngularFire2 - Firebase storage getDownloadURL() - How to return the url for firestore

//observable to store download url
downloadURL: Observable<string>;

task.snapshotChanges().pipe(
    finalize(() => {
        this.downloadURL = fileRef.getDownloadURL();
        this.downloadURL.subscribe(url=>{this.imageUrl = url})
    })
)

refer :https://github.com/ReactiveX/rxjs/blob/master/doc/observable.md

This answer is not relevant from Firebase 5.0 release, they removed downloadURL() from upload task. Please refer to doc.

The .downloadURL() observable emits the download URL string once the upload is completed. Then you need to subscribe to get the value.

uploadImage(base64data) {

  const filePath = (`myURL/photo.jpg`);
  //const storageRef = firebase.storage().ref();

  var metadata = {
    contentType: 'image',
    cacheControl: "public, max-age=31536000",
  };

  const ref = this.storage.ref(filePath);
  const task = ref.putString(base64data, 'data_url', metadata);
  const downloadURL = task.downloadURL();

  downloadURL.subscribe(url=>{
     if(url){
         console.log(url);
         //wirte the url to firestore
     }
  })

}

Hope this helps. check this blog for more detail

.downloadURL() doesn't works longer anymore, you need to use .getDownloadURL() combined with finalize() like so:

.html file

<input type="file" (change)="uploadFile($event)">

.ts file

import {
  AngularFireStorage,
  AngularFireStorageReference,
  AngularFireUploadTask
} from '@angular/fire/storage';
import { Component } from '@angular/core';
import { finalize } from 'rxjs/operators';

@Component({
  selector: 'app-upload',
  templateUrl: './upload.component.html',
  styleUrls: ['./upload.component.scss']
})
export class UploadComponent {
    constructor(private angularFireStorage: AngularFireStorage) {}

    public uploadFile(event: any): void {
        for (let i = 0; i < event.target.files.length; i++) {
            const file = event.target.files[i];
            const fileRef: AngularFireStorageReference = this.angularFireStorage.ref(
              file.name
            );
            const task: AngularFireUploadTask = this.angularFireStorage.upload(
              file.name,
              file
            );
            task
                .snapshotChanges()
                .pipe(
                finalize(() => {
                    fileRef.getDownloadURL().subscribe(downloadURL => {
                        console.log(downloadURL);
                    });
              })
          )
          .subscribe();
       }
   }
}  

Also, note the @angular/fire, it's because all AngularFire2 package is moving into @angular/fire and this is the recommended way to use from now onwards.