preview image in angular 8

<form [formGroup]="uploadForm" (ngSubmit)="submit()">
  <!-- Select File -->
  <input type="file" accept="image/*" (change)="showPreview($event)" />

  <!-- Image Preview -->
  <div class="imagePreview" *ngIf="imageURL && imageURL !== ''">
    <img [src]="imageURL" [alt]="uploadForm.value.name">
  </div>

  <!-- Assign Image Alt -->
  <input formControlName="name" placeholder="Enter name">

  <button type="submit">Submit</button>
</form>

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup } from "@angular/forms";

@Component({
  selector: 'app-file-upload',
  templateUrl: './file-upload.component.html',
  styleUrls: ['./file-upload.component.css']
})

export class FileUploadComponent implements OnInit {
  imageURL: string;
  uploadForm: FormGroup;

  constructor(public fb: FormBuilder) {
    // Reactive Form
    this.uploadForm = this.fb.group({
      avatar: [null],
      name: ['']
    })
  }

  ngOnInit(): void { }


  // Image Preview
  showPreview(event) {
    const file = (event.target as HTMLInputElement).files[0];
    this.uploadForm.patchValue({
      avatar: file
    });
    this.uploadForm.get('avatar').updateValueAndValidity()

    // File Preview
    const reader = new FileReader();
    reader.onload = () => {
      this.imageURL = reader.result as string;
    }
    reader.readAsDataURL(file)
  }

  // Submit Form
  submit() {
    console.log(this.uploadForm.value)
  }

}