CollabTable

A collaborative list management system with Android app and server for creating and managing shared lists with custom fields and items.

Overview

CollabTable allows multiple users to collaboratively create and manage lists with custom fields. Perfect for:

• Shopping lists with price tracking
• Product catalogs
• Task management with custom attributes
• Any structured data collection

Features

Android App

• ✨ Beautiful Material 3 design with dynamic colors
• 📱 Native Android app built with Jetpack Compose
• 💾 Offline-first with Room database
• 🔄 Real-time synchronization via WebSocket (with HTTP fallback)
• 🎨 Custom fields (name, link, price, category, etc.)
• ✏️ Inline editing of items with auto-save
• 📤 Export functionality (CSV format)
• 🗑️ Soft delete support for data recovery
• ⚙️ Configurable server URL and authentication
• 📊 Optimized performance for large tables with thousands of rows
• 🎯 Column alignment options (left, center, right)

Server

• 🚀 Express.js REST API with TypeScript
• 🐳 Fully containerized with Docker
• 💾 Flexible database support: SQLite or PostgreSQL
• 🔄 Advanced sync protocol for conflict resolution
• 🔌 WebSocket support for real-time updates
• 🔐 Optional authentication with shared password
• 📊 Complete CRUD operations for all entities
• 💽 Persistent storage with Docker volumes

Prerequisites

Server

• Docker and Docker Compose (recommended)
• Or Node.js 20+ for local development

Android App

• Android Studio Hedgehog or later
• Android SDK 26+ (Android 8.0 or higher)
• JDK 21
• Android emulator or physical device

Quick Start

Server (Docker)

1. Navigate to server directory:

   cd CollabTableServer
   

2. Copy environment file (optional):

   cp .env.example .env
   

3. Configure authentication (optional): Edit .env and set SERVER_PASSWORD for API protection:

   SERVER_PASSWORD=your_secure_password
   

4. Start the server:

   docker-compose up -d
   

Server runs on http://localhost:3000

Database Options:

• SQLite (default): Data persists in Docker volume sqlite_data
• PostgreSQL: Configure in .env with DB_CLIENT=postgres

Android App

1. Open project in Android Studio:

   • Open CollabTableAndroid folder in Android Studio
   • Wait for Gradle sync to complete

2. Run the app:

   • Run on emulator or physical device

3. Configure server connection:

   • Tap the Settings icon (⚙️) in the top bar
   • Enter your server URL:
     • For emulator: http://10.0.2.2:3000/api/
     • For physical device: http://YOUR_COMPUTER_IP:3000/api/
   • If server has authentication enabled, enter the password
   • Tap "Save"

Note: Make sure to include the trailing /api/ in the URL.

Project Structure

CollabTable/
├── CollabTableAndroid/          # Android app
│   ├── app/
│   │   ├── src/main/java/com/collabtable/app/
│   │   │   ├── data/            # Database, API, repositories
│   │   │   │   ├── api/         # Retrofit interfaces
│   │   │   │   ├── dao/         # Room DAOs
│   │   │   │   ├── database/    # Room database setup
│   │   │   │   ├── model/       # Data models
│   │   │   │   └── repository/  # Repository pattern
│   │   │   └── ui/              # Compose UI
│   │   │       ├── navigation/  # Navigation setup
│   │   │       ├── screens/     # UI screens & ViewModels
│   │   │       └── theme/       # Material 3 theme
│   │   └── build.gradle
│   └── README.md
│
└── CollabTableServer/           # Node.js server
    ├── src/
    │   ├── models/              # Data models & database logic
    │   ├── routes/              # API endpoints
    │   └── index.ts             # Server entry point
    ├── data/                    # SQLite database storage
    ├── Dockerfile
    ├── docker-compose.yml
    └── README.md

Technology Stack

Android

• Language: Kotlin
• UI Framework: Jetpack Compose with Material 3
• Database: Room (SQLite)
• Networking: Retrofit (HTTP), OkHttp WebSocket
• Async: Coroutines & Flow
• Architecture: MVVM with Repository pattern
• Build System: Gradle with Kotlin DSL

Server

• Runtime: Node.js 20+
• Framework: Express.js
• Language: TypeScript
• Database: SQLite (better-sqlite3) or PostgreSQL (pg)
• Containerization: Docker & Docker Compose
• Real-time: WebSocket support

API Endpoints

All endpoints are prefixed with /api/ and can be protected with optional authentication.

Authentication

If SERVER_PASSWORD is set in the server's .env file, include this header in all requests:

Authorization: Bearer your_password_here

Lists

• GET /api/lists - Get all lists
• GET /api/lists/:id - Get a specific list
• POST /api/lists - Create a new list
• PUT /api/lists/:id - Update a list
• DELETE /api/lists/:id - Delete a list (soft delete)

Fields

• GET /api/fields/list/:listId - Get all fields for a list
• POST /api/fields - Create a new field
• PUT /api/fields/:id - Update a field (including alignment)
• DELETE /api/fields/:id - Delete a field (soft delete)

Items

• GET /api/items/list/:listId - Get all items for a list
• GET /api/items/:itemId/values - Get all values for an item
• POST /api/items - Create a new item
• POST /api/items/values - Create/update item values
• PUT /api/items/:id - Update an item
• DELETE /api/items/:id - Delete an item (soft delete)

Sync

• POST /api/sync - Synchronize data (HTTP fallback)
• WebSocket /api/ws - WebSocket endpoint for real-time sync

Health

• GET /health - Server health check

See Server README for detailed API documentation.

Development

Server Development

Local development without Docker:

1. Install dependencies:

   cd CollabTableServer
   npm install
   

2. Create .env file:

   cp .env.example .env
   

3. Start development server with hot reload:

   npm run dev
   

4. Build for production:

   npm run build
   npm start
   

Useful commands:

npm run lint      # Check code style
npm run format    # Auto-format code

Android Development

1. Open CollabTableAndroid in Android Studio

2. Build the project:

   ./gradlew build
   

3. Run linters:

   ./gradlew ktlintCheck    # Check Kotlin code style
   ./gradlew detekt         # Run static analysis
   

4. Format code:

   ./gradlew ktlintFormat
   

Data Model

Database Schema

List

Represents a table/list container:

{
  id: string;           // Unique identifier
  name: string;         // List name
  createdAt: number;    // Creation timestamp
  updatedAt: number;    // Last update timestamp
  isDeleted: boolean;   // Soft delete flag
}

Field

Defines a column/attribute in a list:

{
  id: string;           // Unique identifier
  listId: string;       // Parent list ID
  name: string;         // Field name (e.g., "Price", "Category")
  order: number;        // Display order
  alignment: string;    // Content alignment: "left", "center", "right"
  createdAt: number;    // Creation timestamp
  updatedAt: number;    // Last update timestamp
  isDeleted: boolean;   // Soft delete flag
}

Item

Represents a row in a list:

{
  id: string;           // Unique identifier
  listId: string;       // Parent list ID
  createdAt: number;    // Creation timestamp
  updatedAt: number;    // Last update timestamp
  isDeleted: boolean;   // Soft delete flag
}

ItemValue

The actual value for a specific field of an item:

{
  id: string;           // Unique identifier
  itemId: string;       // Parent item ID
  fieldId: string;      // Associated field ID
  value: string;        // The actual value
  updatedAt: number;    // Last update timestamp
}

Relationships

• One List has many Fields
• One List has many Items
• One Item has many ItemValues (one per Field)

Troubleshooting

Common Issues

Android App

Cannot connect to server

• Verify server is running: visit http://localhost:3000/health in browser
• Check server URL in app settings:
  • Emulator: Use http://10.0.2.2:3000/api/
  • Physical device: Use your computer's IP address
• Ensure trailing /api/ is included in URL
• If server has authentication, verify password is correct

Gradle sync failed

• Update Android Studio to latest version
• Ensure JDK 21 is installed and selected
• Try: File → Invalidate Caches → Invalidate and Restart

Build errors with Room/Kotlin

• Clean and rebuild: Build → Clean Project → Rebuild Project
• Check that you're using compatible versions

Large tables are slow

• Performance is optimized for thousands of rows
• For tens of thousands of rows, consider server-side filtering
• Check that debouncing is enabled (default)

Server

Port 3000 already in use

# Find and kill process using port 3000
lsof -ti:3000 | xargs kill -9
# Or change port in docker-compose.yml or .env

Docker container won't start

# View logs
docker-compose logs -f

# Rebuild container
docker-compose down
docker-compose up -d --build

Database connection error (PostgreSQL)

• Verify PostgreSQL is running
• Check connection details in .env
• Ensure database exists

Data not persisting after container restart

• Verify Docker volume exists: docker volume ls
• Check volume mount in docker-compose.yml
• For SQLite, data is in sqlite_data volume

Getting Help

• Check the Android README for app-specific details
• Check the Server README for server-specific details
• Review Docker logs: docker-compose logs -f
• Open an issue on GitHub with detailed error messages

Synchronization

CollabTable uses a sophisticated sync protocol to keep data consistent across clients:

Sync Strategy

• Primary: WebSocket (/api/ws) for real-time, low-latency sync
• Fallback: HTTP POST (/api/sync) when WebSocket fails
• Conflict Resolution: Latest timestamp wins

How It Works

1. Client → Server: Client sends all local changes since last sync timestamp
2. Server Processing: Server saves client changes and retrieves server changes
3. Server → Client: Server returns changes made since client's last sync
4. Client Update: Client applies server updates locally
5. Timestamp Update: Client stores new server timestamp for next sync

Sync Flow

Client                                Server
  |                                      |
  |-- Sync Request (local changes) ---->|
  |    (lists, fields, items, values)   |
  |                                      |
  |<-- Sync Response (server changes) --|
  |    (updates + new serverTimestamp)  |
  |                                      |

WebSocket Protocol

Send JSON messages to /api/ws:

{
  "type": "sync",
  "id": "unique-request-id",
  "payload": {
    "lastSyncTimestamp": 1234567890,
    "lists": [...],
    "fields": [...],
    "items": [...],
    "itemValues": [...]
  }
}

Response:

{
  "type": "syncResponse",
  "id": "unique-request-id",
  "payload": {
    "lists": [...],
    "fields": [...],
    "items": [...],
    "itemValues": [...],
    "serverTimestamp": 1234567890
  }
}

Features

• Automatic Sync: Triggered on app start and after local changes
• Soft Deletes: Deleted items can be recovered on server
• Optimistic Updates: UI updates immediately, syncs in background
• Performance: Debounced updates for large table operations

Docker & Deployment

Data Persistence

SQLite (Default)

• Database stored in Docker volume: sqlite_data
• Persists across container restarts
• Backup database:

  # Using container name (set in docker-compose.yml)
  docker cp collabtable-server:/data/collabtable.db ./backup.db
  
  # Or using docker-compose (if in server directory)
  docker-compose exec server cat /data/collabtable.db > ./backup.db
  

• Restore database:

  docker cp ./backup.db collabtable-server:/data/collabtable.db
  docker-compose restart
  

PostgreSQL

• Configure in .env: DB_CLIENT=postgres
• Use standard PostgreSQL backup tools (pg_dump, pg_restore)
• Docker volume manages persistence automatically

Docker Commands

Start services:

docker-compose up -d

Stop services:

docker-compose down

View logs:

docker-compose logs -f

Rebuild and restart:

docker-compose up -d --build

Check running containers:

docker ps

Production Deployment

Environment Variables Configure these in .env or docker-compose.yml:

PORT=3000                           # Server port
NODE_ENV=production                 # Environment
SERVER_PASSWORD=your_secure_pass    # API authentication (recommended)
DB_CLIENT=sqlite                    # Database: sqlite or postgres
DB_PATH=/data/collabtable.db       # SQLite path (in container)

Security Recommendations

1. Set SERVER_PASSWORD for production
2. Use HTTPS with a reverse proxy (nginx, Caddy)
3. Regular database backups
4. Keep Docker images updated
5. Restrict network access to server ports

Reverse Proxy Example (nginx)

server {
    listen 80;
    server_name example.com;
    
    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

Contributing

Contributions are welcome! Here's how you can help:

Getting Started

1. Fork the repository
2. Create a feature branch: git checkout -b feature/your-feature-name
3. Make your changes
4. Test your changes thoroughly
5. Commit with clear messages: git commit -m "feat: add new feature"
6. Push to your fork: git push origin feature/your-feature-name
7. Open a Pull Request

Development Guidelines

Code Style

• Android: Follow Kotlin conventions, use ktlint for formatting
• Server: Follow TypeScript/JavaScript conventions, use Prettier
• Keep functions small and focused
• Write meaningful variable and function names
• Add comments for complex logic

Testing

• Test your changes on both emulator and physical devices (Android)
• Test with both SQLite and PostgreSQL backends (Server)
• Verify sync works correctly with multiple clients
• Test with large datasets to ensure performance

Commit Messages Follow conventional commits:

• feat: for new features
• fix: for bug fixes
• docs: for documentation changes
• style: for formatting changes
• refactor: for code refactoring
• test: for adding tests
• chore: for maintenance tasks

Areas for Contribution

Features

• Additional export formats (JSON, Excel)
• Search and filter functionality
• Batch operations
• User authentication and permissions
• Drag-and-drop row reordering
• Rich text field support

Improvements

• Performance optimization for very large tables
• Better offline support
• Enhanced error handling
• Accessibility improvements
• Internationalization (i18n)

Documentation

• API documentation improvements
• Tutorial videos or blog posts
• Translation to other languages
• More code examples

Pull Request Guidelines

• Keep PRs focused on a single feature or fix
• Update documentation if needed
• Ensure all tests pass
• Add screenshots for UI changes
• Reference any related issues

License

MIT