flutter_ftp_dtp 1.0.0

Flutter package for LAN-based File Transfer Pattern (FTP) and Data Transfer Pattern (DTP) — one-shot JSON sharing over HTTP and realtime sync over WebSocket.

Flutter FTP & DTP

A Flutter package for LAN-based local data sharing between devices on the same Wi-Fi network. Extracted from the RUPOS dine-in table management module.

Pattern	Name	Transport	Use case
FTP	File Transfer Pattern	HTTP GET	One-shot JSON export/import (setup sharing)
DTP	Data Transfer Pattern	WebSocket	Realtime bidirectional sync (live collaboration)

Features

• No cloud required — devices communicate directly over the local network
• QR + manual pairing — scan a QR code or enter IP + port + token
• Token-gated security — 6-character alphanumeric tokens on every connection
• Cross-platform — Android, iOS, macOS, Windows, Linux (host); Web (client join only)
• Pluggable storage — wire FTP/DTP to your own Hive, SQLite, or in-memory store
• Ready-made UI — optional dialogs for share, import, and live sync flows

Quick start

1. Add dependency

dependencies:
  flutter_ftp_dtp: ^1.0.0

See INSTALLATION.md for full platform setup.

2. File Transfer Pattern (FTP)

import 'package:flutter_ftp_dtp/flutter_ftp_dtp.dart';

final shareService = LocalFileShareService(
  label: 'My App Data',
  buildExport: () => {'items': myData.toJson()},
  importExport: (json) async {
    myData.loadFrom(json);
    return ImportSummary(itemCount: myData.length);
  },
);

// Host — show QR dialog
await showFileShareDialog(context, service: shareService);

// Client — import from host
await showFileImportDialog(context, service: shareService);

3. Data Transfer Pattern (DTP)

class MySyncAdapter implements SyncAdapter {
  @override
  Future<Map<String, dynamic>> buildSnapshot() async => {...};

  @override
  Future<void> applyRemote(SyncMessage message) async {...}

  @override
  void startWatching(void Function(SyncMessage) onLocalChange) {...}

  @override
  Future<void> stopWatching() async {...}
}

final engine = RealtimeSyncEngine(MySyncAdapter());
await showRealtimeSyncDialog(context, engine: engine);

Example app

cd example
flutter pub get
flutter run

The example demonstrates both patterns with a simple shared-notes app.

Platform support

Platform	FTP Host	FTP Client	DTP Host	DTP Client
Android	✅	✅	✅	✅
iOS	✅	✅	✅	✅
macOS	✅	✅	✅	✅
Windows	✅	✅	✅	✅
Linux	✅	✅	✅	✅
Web	❌	✅	❌	✅

Hosting requires dart:io (native platforms). Web can join as a client but cannot host.

Architecture

┌─────────────────────────────────────────────────────────┐
│                    Your Flutter App                      │
│  ┌──────────────┐              ┌──────────────────────┐ │
│  │ LocalFile    │              │ RealtimeSyncEngine   │ │
│  │ ShareService │              │ + SyncAdapter        │ │
│  └──────┬───────┘              └──────────┬───────────┘ │
│         │                                  │             │
│  ┌──────▼───────┐              ┌─────────▼──────────┐  │
│  │ ShareHttp    │              │ SyncWsServer       │  │
│  │ Server       │              │ (WebSocket host)   │  │
│  │ GET /data.json│             │ GET /sync          │  │
│  └──────────────┘              └────────────────────┘  │
└─────────────────────────────────────────────────────────┘
         │ LAN (same Wi-Fi)              │
         ▼                               ▼
    Receiver device(s)            Joining device(s)

Protocol

FTP QR payload

{"v":1,"ip":"192.168.1.25","port":8080,"token":"A9X8M2","label":"My Store","path":"/data.json","mode":"share"}

DTP QR payload

{"ip":"192.168.1.25","port":8080,"token":"A9X8M2","path":"/sync","mode":"sync"}

WebSocket message envelope

{"t":"entity_upsert","o":"dev_...","id":"item_id","ts":1234567890,"d":{...}}

Documentation

• Installation Guide
• Changelog
• HTML Overview — interactive documentation
• RUPOS Table Management UI Reference — original design prototype

Origin

This package was extracted from the RUPOS application's Table Management module:

• TableShareService → LocalFileShareService (FTP)
• DineSyncService → RealtimeSyncEngine (DTP)

The original Rupos code is unchanged — this is a standalone copy for reuse in other Flutter projects.

License

MIT — see LICENSE. Copyright © 2026 CI Global Technologies.