Phoenix LiveView is an Elixir-based framework that renders HTML on the server and sends only the changed parts to the client over a persistent WebSocket connection. It operates on a process-per-connection model, where each user session runs in its own isolated Elixir process for fault tolerance and independent state management, and includes a LongPolling fallback transport for environments where WebSocket connections are unavailable.
The framework provides server-side rendered diffs and WebSocket-based state synchronization to maintain a continuous bidirectional channel between server and client without full page reloads. It includes a client-side hook system that allows custom JavaScript to intercept and extend LiveView lifecycle events and DOM interactions, compile-time template optimization to minimize runtime overhead, and a form state recovery protocol that automatically restores input values when a LiveView reconnects after a network interruption or server crash.
The framework supports real-time form validation on the server as the user types, file uploads over WebSocket with progress tracking and chunked processing, and navigation without full page loads. It also provides a testing framework that simulates user interactions on the server side to verify LiveView behavior without needing a full browser, and a server-side component inspector for troubleshooting interactive applications.
