Image preview before upload in angular 5

Question

.html

Answer 1

I know I'm late but just ran into this problem for both image and audio. The above solutions worked just fine for images but not so well for audio. I eventually got it all working by using a URL object instead of FileReader object that everyone is using. something like the following

component.ts file ~

imgSrc = 'assets/path/to/default/image.jpeg'

imgFileSelected(event: any) {
  if (event.target.files && event.target.files[0]) {
    this.imgSrc = URL.createObjectURL(event.target.files[0]);
  }
}

My component.html looks like~

Finally I created a custom pipe to rid the console of warnings. my pipe is as follows~

@Pipe({
  name: 'sanitizerUrl'
})
export class SanitizerUrlPipe implements PipeTransform {

  constructor (
    private sanitize: DomSanitizer
  ) {}

  transform(value: string): SafeUrl {
    return this.sanitize.bypassSecurityTrustUrl(value);
  }
}

To see how I used this for the audio tag you can check out this link. It's only 2 extra lines of self-explanatory code.