Upload files to firebase for angular

files.ts

filebuttoni(event) {
      let files = event.srcElement.files[0];
      let self = this;
      let uploader = document.getElementById("uploader");
      this.path = "user-profile-pics/"+files.name;
      this.storageref = this.storage.child(this.path);
      let uploadTask = this.storageref.put(files);

      uploadTask.on(firebase.storage.TaskEvent.STATE_CHANGED, function(snapshot) {
        let progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
        console.log('Upload is ' + progress + '% done!');
        switch(snapshot.state) {
          case firebase.storage.TaskState.PAUSED:
          console.log('upload is paused');
          break;
          case firebase.storage.TaskState.RUNNING:
          console.log('Upload is running');
          break;
        }
      }, function(error) {
      switch (error) {
        case 'storage/unauthorized':
          break;

        case 'storage/canceled':
          break;

        case 'storage/unknown':
          break;
      }
    }, function() {
        let downloadURL = uploadTask.snapshot.downloadURL;
        console.log('Upload done!');
        self.storageref.getDownloadURL().then(url => self.newPhotoURL = url);
      });

    }

uploader.html

<input type="file" id="filebutton" value="upload" #filebtn (change)="filebuttoni($event)">