xslt-lab/CLAUDE.md

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

XSLT Lab is an online XSLT editor and tester that uses Saxon for XSLT 2.0/3.0 transformations. The application consists of a React frontend and a Go backend that orchestrates Java/Saxon for XSLT processing.

Build Commands

# Full stack with Docker Compose (lightweight, no database)
make compose-up
make compose-down

# Backend (Go)
cd backend/src && go build -o ../server
cd backend && ./server

# Frontend (React/Vite)
cd frontend && npm install
VITE_BACKEND_URL=http://localhost:8000 npm run dev

# Testing
make backend-test        # Go tests: go test ./...
make frontend-test       # npm tests: vitest

# Docker images
make backend-image
make frontend-image

Architecture

Frontend (/frontend)

• React 18 + Vite SPA
• App.jsx is the monolithic state container managing all workspace state, tabs, transformations
• Monaco Editor for code editing (lazy-loaded)
• LocalStorage persistence for workspace data (up to 3 workspaces)
• /lib/workspaceUtils.js contains utility functions for parameter extraction, error parsing, XSLT manipulation

Backend (/backend)

• Go/Gin HTTP server on port 8000
• Executes Saxon via java command with generated args file
• POST /transform - Main endpoint accepting {xslt, version, parameters, trace}
• 10-second timeout per transformation
• /ext/ contains Java custom extension functions (uuid, date, base64, etc.)

Data Flow

Frontend (POST /transform) → Go Backend → java/Saxon → Parse trace/result → JSON response

Pro Features (when VITE_GO_PRO=true)

• Firebase authentication
• PostgreSQL history storage
• /history endpoint

Key Environment Variables

Frontend (build-time):

• VITE_BACKEND_URL - Backend API endpoint
• VITE_GO_PRO - Enable Pro features
• VITE_FIREBASE_CONFIG - Firebase configuration

Backend:

• DATABASE_URL - PostgreSQL connection (Pro mode)
• SAXON_CLASSPATH - Path to Saxon JARs (default in app.config)

Configuration Files

• /backend/app.config - Backend port and Saxon classpath
• /docker-compose.local.yml - Lightweight dev stack (no DB)
• /docker-compose.yml - Full stack with PostgreSQL
• /charts/xslt-playground/ - Helm chart for Kubernetes deployment