owlnext-dropzone

Owlnext dropzone wrapper

FileUtils.downloadFile() -> Breaking change on web

if you want to use FileUtils.downloadFile() on web context, you will need to inject a specific behavior from your app. create a file in your app, loaded only in library.html context (web) and call

import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:universal_html/html.dart';
import 'package:owlnext_dropzone/owlnext_dropzone.dart';

/// Utility to enable file downloads on Flutter Web when using `owlnext_dropzone`.
///
/// # Why
/// By default, `owlnext_dropzone` cannot handle web downloads without
/// depending on `universal_html`. This class injects a web-only implementation
/// so your app controls the download behavior.
///
/// # How
/// - Call [InitWebDownload.setup] in `main.dart`.
/// - On Web, it registers a custom download function that:
///   1. Encodes file bytes to Base64
///   2. Creates a temporary `<a>` element with a `data:` URI
///   3. Triggers the browser’s native download
///   4. Cleans up the element
///
/// # Example
/// ```dart
/// void main() {
///   InitWebDownload.setup();
///   runApp(MyApp());
/// }
/// ```
class InitWebDownload {
  static void setup() {
    if (kIsWeb) {
      DownloadFileWebBypass().setDownloadFileWebFunction(_downloadFileWebImplementation);
    }
  }

  Future<void> _downloadFileWebImplementation(Uint8List bytes, String fileName, String extension) async {
    final base64 = base64Encode(bytes);
    final anchor = AnchorElement(href: 'data:application/octet-stream;base64,$base64')
      ..target = 'blank'
      ..download = fileName;
    document.body?.append(anchor);
    anchor.click();
    anchor.remove();
  }
}

Debugging

to see debug messages (in debugModeOnly), put this in your app main.dart

OwlnextDropzoneDebuger.kDebugOwlnextDropzone = true;