Advanced Topics

📄️ Error Handling

Register custom ErrorHandler implementations through the Java Service Provider Interface to respond to specific exceptions in webforJ apps.

Hook into webforJ app startup and shutdown phases with AppLifecycleListener to initialize services, modify config, or clean up resources.

Configure the app locale, auto-detect from the browser, and react to runtime language switches through the LocaleObserver interface.

Resolve localized strings from resource bundles or custom sources with the t() method, MessageFormat placeholders, and browser locale detection.

Log messages from Java to the browser console with typed levels and styled output using the BrowserConsole utility.

Format and parse strings, numbers, dates, and times outside input fields using the same mask syntax as webforJ masked fields.

Schedule recurring events at a fixed delay using the Interval class to refresh data, rotate content, or detect inactivity efficiently.

Delay actions until activity settles using the Debouncer class for search-as-you-type, autosave, and other rate-limited UI work.

Customize app shutdown and error behavior with AppCloseAction implementations like MessageAction, RedirectAction, and NoneAction.

Navigate, push, and replace browser history entries from Java to control back, forward, and URL state without page reloads.

Detect when the tab hosting your app moves between the foreground and the background, and react in Java.

Request and watch the device's geographic position using the Geolocation class, with high-accuracy, timeout, and maximum age controls.

Persist client-side data through CookieStorage, SessionStorage, and LocalStorage to retain preferences and state across requests and reloads.

Paint notification badges onto the operating system app icon and the browser tab favicon.

Share thread-safe key-value state across sessions, thread groups, or the entire JVM using Private, Group, and Global namespaces.

Animate DOM changes with the browser View Transition API, applying fade, slide, zoom, and shared morph effects between component states.

Store shared Java objects and string values app-wide or per HTTP session with ObjectTable, SessionObjectTable, and StringTable.

3 items

Run background work off the UI thread and push updates back to webforJ components safely with Environment.runLater and PendingResult.

Override default route scanning with a custom SPI provider to integrate Spring, CDI, OSGi, or GraalVM classloaders with webforJ routing.