Quick start

Add file previews to a Flutter screen. FileViewerHost owns application-scoped warm-up, FileViewer displays a document, and offline resources ship with your application.

Before you begin

Use Flutter 3.47 or later and Dart 3.13 or later. The published release is 0.1.0-dev.1, a development preview. See platform setup for the measured Android, iOS, Web, Windows, macOS and Linux scope. The pinned qualification toolchain is Flutter 3.47.4 / Dart 3.13.3.

Customer applications need Flutter tooling. They do not need Node.js or a JavaScript source build.

1. Install the package

Add the dependency to your application's pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter
  file_viewer_flutter: 0.1.0-dev.1

flutter pub get

The entry package installs four matching offline asset packages and two first-party platform adapters. Keep your application's pubspec.lock; do not override an individual resource package to another version.

2. Configure your host

Run once from the customer application's root:

dart run file_viewer_flutter:setup --project . --check
dart run file_viewer_flutter:setup --project . --apply

--check previews the diff; only --apply writes changes. The command preserves existing settings and adds local-resource configuration and platform initialization for platform directories that exist in the application. Use --platform android,ios to select a subset. Web needs no configuration changes from this command.

Perform a full rebuild afterward. Hot reload does not apply native host changes. See platform setup for operating-system and build requirements.

3. Add a document

Place a PDF at assets/example.pdf and declare it in the same pubspec.yaml:

flutter:
  uses-material-design: true
  assets:
    - assets/example.pdf

You can also download the repository's owned PDF fixture to that path. Keep customer documents out of public repositories.

4. Display it

Place this complete example in lib/main.dart:

import 'package:flutter/material.dart';
import 'package:file_viewer_flutter/file_viewer_flutter.dart';

void main() {
  runApp(const FileViewerHost(child: PreviewApp()));
}

class PreviewApp extends StatelessWidget {
  const PreviewApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'File Viewer Flutter',
      home: Scaffold(
        appBar: AppBar(title: const Text('File preview')),
        body: const FileViewer(
          source: FileViewerSource.asset('assets/example.pdf'),
        ),
      ),
    );
  }
}

flutter run

Scaffold.body gives the viewer a bounded layout. Use Expanded inside a Column, or give another parent an explicit size. Keep the application Host across preview routes.

Continue integrating

• Document sources: bundled assets, native paths, bytes and authenticated URLs.
• Warm-up and lifecycle: preloading, route reuse, concurrency and logout.
• Controllers and events: readiness, search, zoom, reload and recovery.
• Offline delivery: Web assets, desktop engines, package size and licenses.

To run the complete example, clone the independent repository, run flutter pub get in both the repository root and example/, then run the host setup command and flutter run from example/.