Tauri- und Rust-Integration

Tauri & Rust Integration

Tauri pairs a system WebView frontend with a Rust core process. Keep the Rust core responsive, type-safe, and governed by Tauri v2's fine-grained capability security model.

Designing Safe, Non-Blocking #[tauri::command] Handlers

1. Use async commands for all I/O and subprocess work:
   • Synchronous #[tauri::command] fn my_cmd() runs on the main UI thread and freezes the window if it blocks on disk, SQLite, or child processes. Declare #[tauri::command] async fn my_cmd(...) -> Result<OutputDto, AppError>.
2. Serializable, typed error handling (Result<T, AppError>):
   • Implement serde::Serialize on a structured AppError { code: &'static str, message: String } (using thiserror) so the frontend receives machine-readable error codes rather than opaque string panics.
3. Thread-safe managed state (tauri::State):
   • Register shared application state (app.manage(AppState { ... })) wrapped in tokio::sync::Mutex / RwLock (for async guards held across .await) or std::sync::Mutex (only for fast synchronous lock/unlock blocks—never hold a std::sync::MutexGuard across .await!).
4. Streaming events & binary payloads:
   • For high-frequency progress streams or terminal/agent logs, use tauri::ipc::Channel<EventPayload> passed as a command argument (or scoped app.emit_to(window_label, ...)), which avoids global broadcast overhead.

Tauri v2 Capabilities & Permissions (src-tauri/capabilities/)

Tauri v2 enforces an explicit Access Control List (ACL) per window/webview:

• Define capability files in src-tauri/capabilities/default.json targeting specific windows ("windows": ["main"]).
• Grant only the exact plugin permissions required ("dialog:allow-open", "fs:allow-app-data-recursive", "opener:default").
• When exposing custom Rust commands in a workspace plugin or build.rs, register const COMMANDS: &[&str] and declare explicit allow / deny scopes rather than opening unrestricted filesystem or shell access.

Sidecar Binaries (externalBin) & Lifecycle

Remember that Tauri does not bundle Node.js:

• If the application requires a local Node/Python/Go daemon, compile it into a standalone executable per target triple (binaries/server-aarch64-apple-darwin, binaries/server-x86_64-pc-windows-msvc.exe) and register "externalBin": ["binaries/server"] in tauri.conf.json.
• Spawn the sidecar from Rust via app.shell().sidecar("server")?.args([...]).spawn()?, store the CommandChild handle in managed state, and hook RunEvent::ExitRequested / RunEvent::Exit in .build(...).run(|app_handle, event| ...) to terminate the sidecar cleanly when the app exits.