paperless-ngx/src-ui/src/app/pipes/safe.pipe.ts

import { Pipe, PipeTransform } from '@angular/core'
import { DomSanitizer } from '@angular/platform-browser'

@Pipe({
  name: 'safe',
})
export class SafePipe implements PipeTransform {
  constructor(private sanitizer: DomSanitizer) {}

  transform(url) {
    if (url == null) {
      return this.sanitizer.bypassSecurityTrustResourceUrl('')
    } else {
      return this.sanitizer.bypassSecurityTrustResourceUrl(url)
    }
  }
}