6de61b965e
A new `template` value source evaluates a hardened, sandboxed Jinja expression over the live values of other value sources — the system's first float combinator. Backend: - Shared engine (utils/template_expr.py): ImmutableSandboxedEnvironment with filters/tests and auto-injected globals stripped; only min/max/abs/round/ clamp exposed; rejects **, string/collection-literal repetition, attribute access and non-global calls; NaN/inf-safe result coercion. - TemplateValueSource model + TemplateValueStream runtime: compile-once, primitives-only eval context, raw[name] exposure, eval_interval throttle, ref-counted input acquire/release, rename-safe hot-update. - Validation: unbound-variable + reserved-name rejection, reference cycle/depth guards (depth-only at create, full cycle at update), runtime acquire() depth backstop, and delete referential-integrity. - API: Create/Update/Response schemas + discriminated unions, _RESPONSE_MAP, and an advisory POST /value-sources/validate-template endpoint. - Demo seed: a static source plus a template combinator example. Frontend: - Editor modal section: repeatable inputs list (EntitySelect rows), a zero-dependency Jinja syntax highlighter, a hints/reference panel, and a debounced live validator that gates Save (stale-response-safe). - Graph editor: read-only template node with one edge per input. - i18n (en/ru/zh), icon, and card rendering. Tests: engine, stream, factory/cycle, validate endpoint, and demo seed.
LedGrab - Server
High-performance FastAPI server that captures screen content and controls WLED devices for ambient lighting.
Overview
The server component provides:
- 🎯 Real-time Screen Capture - Multi-monitor support with configurable FPS
- 🎨 Advanced Processing - Border pixel extraction with color correction
- 🔧 Flexible Calibration - Map screen edges to any LED layout
- 🌐 REST API - Complete control via 25+ REST endpoints
- 💾 Persistent Storage - JSON-based device and configuration management
- 📊 Metrics & Monitoring - Real-time FPS, status, and performance data
Quick Start
Option 1: Docker (Recommended)
# Start server
docker-compose up -d
# View logs
docker-compose logs -f
# Stop server
docker-compose down
Server runs on: http://localhost:8080
Option 2: Python
# Create virtual environment
python -m venv venv
# Activate
source venv/bin/activate # Linux/Mac
venv\Scripts\activate # Windows
# Install dependencies
pip install .
# Set PYTHONPATH
export PYTHONPATH=$(pwd)/src # Linux/Mac
set PYTHONPATH=%CD%\src # Windows
# Run server
uvicorn ledgrab.main:app --host 0.0.0.0 --port 8080
Installation
Requirements
- Python 3.11+ (for Python installation)
- Docker & Docker Compose (for Docker installation)
- WLED device on your network
See ../INSTALLATION.md for comprehensive installation guide.
Configuration
Configuration File
Edit config/default_config.yaml:
server:
host: "0.0.0.0"
port: 8080
log_level: "INFO"
processing:
default_fps: 30 # Target frames per second
max_fps: 60 # Maximum allowed FPS
border_width: 10 # Pixels to sample from edge
wled:
timeout: 5 # Connection timeout (seconds)
retry_attempts: 3 # Number of retries
storage:
devices_file: "data/devices.json"
logging:
format: "json"
file: "logs/ledgrab.log"
Environment Variables
# Server configuration
export LEDGRAB_SERVER__HOST="0.0.0.0"
export LEDGRAB_SERVER__PORT=8080
export LEDGRAB_SERVER__LOG_LEVEL="INFO"
# Processing configuration
export LEDGRAB_PROCESSING__DEFAULT_FPS=30
export LEDGRAB_PROCESSING__BORDER_WIDTH=10
# WLED configuration
export WLED_WLED__TIMEOUT=5
Usage
WLED Device Setup
Important: Configure your WLED device using the official WLED web interface before connecting it to this controller:
- Access WLED Interface: Open
http://[wled-ip]in your browser - Configure Device Settings:
- Set LED count and type
- Configure brightness, color order, and power limits
- Set up segments if needed
- Configure effects and presets
This controller only sends pixel color data - it does not manage WLED settings like brightness, effects, or segments. All WLED device configuration should be done through the official WLED interface.
API Documentation
- Web UI: http://localhost:8080 (recommended for device management)
- Swagger UI: http://localhost:8080/docs
- ReDoc: http://localhost:8080/redoc
Quick Example
# 1. Add device
curl -X POST http://localhost:8080/api/v1/devices \
-H "Content-Type: application/json" \
-d '{"name":"Living Room","url":"http://192.168.1.100","led_count":150}'
# 2. Start processing
curl -X POST http://localhost:8080/api/v1/devices/{device_id}/start
# 3. Check status
curl http://localhost:8080/api/v1/devices/{device_id}/state
Testing
# Run all tests
pytest
# Run with coverage
pytest --cov=ledgrab --cov-report=html
# Run specific test
pytest tests/test_screen_capture.py -v
Development
Project Structure
src/ledgrab/
├── main.py # FastAPI application
├── config.py # Configuration
├── api/ # API routes
├── core/ # Core functionality
│ ├── screen_capture.py
│ ├── wled_client.py
│ ├── calibration.py
│ └── processor_manager.py
├── storage/ # Data persistence
└── utils/ # Utilities
Code Quality
# Format code
black src/ tests/
# Lint code
ruff check src/ tests/
License
MIT - see ../LICENSE