PDF Editor

A full-stack PDF editor application with React Native frontend and Flask backend.

Features

Core PDF Operations

• Upload PDF - Upload and store PDF files
• View PDFs - Browse and view your PDF documents
• Merge PDFs - Combine multiple PDF files into one
• Split PDF - Extract specific pages from a PDF
• Rotate Pages - Rotate pages in your PDF documents
• Delete Documents - Remove PDF documents from the system
• Rename Documents - Update document metadata and filenames

Advanced PDF Operations

• Add Watermark - Add text watermarks with custom position and opacity
• Encrypt PDF - Password-protect PDF files with encryption
• Decrypt PDF - Remove password protection from PDFs
• Compress PDF - Reduce file size with quality control (low, medium, high)
• PDF to Images - Convert PDF pages to PNG/JPG images
• Images to PDF - Create PDF from multiple image files
• OCR Text Extraction - Extract text from scanned PDFs using OCR
• Page Reordering - Reorder, duplicate, or remove specific pages
• PDF Thumbnails - Generate preview thumbnails for PDF pages

Document Management

• Search & Filter - Search documents by name and filter results
• Sort Documents - Sort by name, size, pages, or date
• Document Statistics - View total documents, storage used, and page counts
• Metadata Editor - View and edit PDF metadata (title, author, subject, etc.)

User Management

• User Authentication - Register and login with JWT tokens
• User Accounts - Personal document library per user
• Session Management - Secure session handling with Redis

Tech Stack

Backend

• Flask - Python web framework
• PostgreSQL - Database for storing document metadata
• Redis - Caching, session management, and job queue
• PyPDF2 - PDF manipulation library
• PyMuPDF (fitz) - Advanced PDF operations and rendering
• reportlab - PDF generation and watermarking
• pikepdf - PDF encryption and security
• pdf2image - PDF to image conversion
• pytesseract - OCR text extraction
• img2pdf - Image to PDF conversion
• Flask-JWT-Extended - JWT authentication
• Flask-Bcrypt - Password hashing
• Celery - Background task processing

Frontend

• React Native - Cross-platform mobile framework
• Expo - Development platform
• React Native Paper - Material Design components
• React Navigation - Navigation library

Infrastructure

• Docker - Containerization
• Docker Compose - Multi-container orchestration

Prerequisites

• Docker and Docker Compose
• Node.js 18+ (for frontend development)
• Python 3.11+ (for local backend development)
• Tesseract OCR (for OCR functionality)
  • Windows: Download from GitHub
  • Mac: brew install tesseract
  • Linux: sudo apt-get install tesseract-ocr
• Poppler (for PDF to image conversion)
  • Windows: Download from GitHub
  • Mac: brew install poppler
  • Linux: sudo apt-get install poppler-utils

Quick Start

1. Clone the repository

git clone <repository-url>
cd pdf_editor_project

2. Configure environment variables (optional)

Create a .env file in the backend directory:

# Database
DATABASE_URL=postgresql://postgres:postgres@db:5432/pdfeditor

# Redis
REDIS_HOST=redis
CELERY_BROKER_URL=redis://redis:6379/0
CELERY_RESULT_BACKEND=redis://redis:6379/0

# Security
JWT_SECRET_KEY=your-secret-key-change-in-production

# File Upload
MAX_CONTENT_LENGTH=104857600  # 100MB

3. Start the backend services with Docker

docker-compose up -d

This will start:

• PostgreSQL database on port 5432
• Redis on port 6379
• Flask backend on port 5000

3. Verify backend is running

curl http://localhost:5000/health

You should see:

{
  "status": "healthy",
  "database": "connected",
  "redis": "connected"
}

4. Set up the frontend

cd frontend
npm install

5. Update API URL

Edit frontend/src/services/api.js and update the API_BASE_URL:

// For local development
const API_BASE_URL = 'http://localhost:5000/api';

// For Android emulator
// const API_BASE_URL = 'http://10.0.2.2:5000/api';

// For iOS simulator
// const API_BASE_URL = 'http://localhost:5000/api';

// For physical device (replace with your computer's IP)
// const API_BASE_URL = 'http://192.168.1.XXX:5000/api';

6. Start the frontend

npm start

Then:

• Press w for web
• Press a for Android
• Press i for iOS
• Scan QR code with Expo Go app on your phone

API Endpoints

Health Check

• GET /health - Check backend health status

Authentication

• POST /api/auth/register - Register a new user
• POST /api/auth/login - Login user
• GET /api/auth/me - Get current user info (requires JWT)

Documents

• POST /api/upload - Upload a PDF file
• GET /api/documents - List all documents (supports search, sort, filter)
• GET /api/documents/<id> - Get document details
• PUT /api/documents/<id> - Update document metadata (rename)
• DELETE /api/documents/<id> - Delete a document
• GET /api/documents/<id>/download - Download a document
• GET /api/documents/<id>/thumbnail?page=1 - Get page thumbnail
• GET /api/documents/stats - Get document statistics

Core Operations

• POST /api/merge - Merge multiple PDFs
• POST /api/split - Split a PDF by pages
• POST /api/rotate - Rotate PDF pages
• POST /api/reorder - Reorder PDF pages
• GET /api/operations - List all operations
• GET /api/operations/<id> - Get operation status

Advanced Operations

• POST /api/watermark - Add watermark to PDF
• POST /api/encrypt - Encrypt PDF with password
• POST /api/decrypt - Decrypt PDF
• POST /api/compress - Compress PDF file
• POST /api/pdf-to-images - Convert PDF pages to images
• POST /api/images-to-pdf - Convert images to PDF
• POST /api/ocr - Extract text using OCR

Redis Usage

Redis is used for:

1. Caching - Document metadata caching (1 hour TTL) ✅
2. Session Management - JWT token management and user sessions ✅
3. Job Queue - Celery broker for background task processing ✅
4. Rate Limiting - API rate limiting (future feature)

Docker Commands

# Start all services
docker-compose up -d

# Stop all services
docker-compose down

# View logs
docker-compose logs -f backend

# Rebuild backend
docker-compose up -d --build backend

# Access database
docker exec -it pdf_editor_db psql -U postgres -d pdfeditor

# Access Redis CLI
docker exec -it pdf_editor_redis redis-cli

Development

Backend Development

cd backend
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate
pip install -r requirements.txt
python app.py

Frontend Development

cd frontend
npm start

Project Structure

pdf_editor_project/
├── backend/
│   ├── app.py              # Flask application
│   ├── requirements.txt    # Python dependencies
│   ├── Dockerfile          # Backend Docker image
│   └── .env.example        # Environment variables template
├── frontend/
│   ├── src/
│   │   ├── screens/        # React Native screens
│   │   └── services/       # API service layer
│   ├── App.js              # Main app component
│   ├── package.json        # Node dependencies
│   └── app.json            # Expo configuration
├── docker-compose.yml      # Docker orchestration
└── README.md               # This file

Troubleshooting

Backend not connecting to database

• Ensure PostgreSQL container is healthy: docker-compose ps
• Check logs: docker-compose logs db

Frontend can't reach backend

• Verify backend is running: curl http://localhost:5000/health
• Update API_BASE_URL in frontend/src/services/api.js
• For Android emulator, use 10.0.2.2 instead of localhost
• For physical device, use your computer's local IP address

Redis connection issues

• Check Redis is running: docker-compose ps redis
• Test connection: docker exec -it pdf_editor_redis redis-cli ping

Implemented Features ✅

• Add watermark functionality
• User authentication and authorization
• PDF compression
• OCR text extraction
• PDF encryption/decryption
• PDF to image conversion
• Image to PDF conversion
• Page reordering
• PDF preview thumbnails
• Document search and filtering
• Document statistics dashboard
• Metadata editor
• Delete and rename documents

Future Enhancements

• PDF annotation tools (highlights, comments, drawings)
• Cloud storage integration (Google Drive, Dropbox, OneDrive)
• Advanced batch processing with progress tracking
• PDF comparison tool
• Form filling and extraction
• Digital signatures
• PDF/A conversion for archiving
• Advanced OCR with language selection
• Collaborative editing
• API rate limiting
• Email PDF documents
• Schedule automated PDF operations

Documentation

• Quick Start Guide - Get started in 5 minutes! ⚡
• API Documentation - Complete API reference with examples
• Testing Guide - Comprehensive testing instructions
• Implementation Summary - Feature overview and deployment guide

License

MIT