Complete reference for all PraxisJS decorators — organized by category with descriptions and links.

Decorators

All decorators are imported from @praxisjs/decorators unless noted otherwise.

Looking for a specific decorator? Use the table below to find it, then follow the link to the full documentation page.

State & Props

Reactive state on class fields. → Full page

Decorator	What it does
`@State()`	Field backed by a signal. Reading inside `{() => ...}` subscribes to updates.
`@Prop()`	External prop received from the parent. Initialized value is the default.
`@Computed()`	Read-only derived getter, cached as a `computed()`. Recomputes only when its signal dependencies change.
`@Persisted(key?)`	Like `@State` but persisted to `localStorage` with optional cross-tab sync.
`@History(field, limit?)`	Adds `.undo()`, `.redo()`, `.canUndo()`, `.canRedo()` to a `@State` field.
`@Resource(fetcher)`	Async data field — tracks `.pending()`, `.error()`, `.data()`. Auto-refetches when signals inside the fetcher change.
`@Synced(channel?)`	Like `@State` but synced across all open browser tabs via `BroadcastChannel`.
`@DeepState()`	Like `@State` but nested mutations (push, property assignment) are reactive via a deep `Proxy`.

Side effects that run when reactive state changes. → Full page

Decorator	What it does
`@Watch(...props)`	Calls the method when any listed property changes. Multiple changes in one tick are coalesced into one call.
`@When(prop)`	Calls the method exactly once — the first time the property becomes truthy.
`@Until(prop)`	Replaces the method with one that returns a `Promise` resolving to the first truthy value of the property.

Communication between components. → Full page

Decorator	What it does
`@Emit(propName)`	Binds `this`, calls the named prop callback with the method's return value when the method runs.
`@Slot(name?)`	Declares a named slot — collects children distributed via `slot="name"` on the parent's JSX.
`@OnCommand(propName)`	Subscribes the method to a `Command` prop bus. Auto-unsubscribes on unmount.

Execution rate control for methods. → Full page

Decorator	What it does
`@Debounce(ms)`	Delays execution — timer resets on every call. Fires after the last call settles. Cleaned up on unmount.
`@Throttle(ms)`	Executes on the leading edge, then ignores calls for `ms` milliseconds.

General-purpose method helpers. → Full page

Decorator	What it does
`@Bind()`	Binds the method to the instance — useful when passing methods as callbacks without arrow function wrappers.
`@Log(options?)`	Logs calls with arguments, return value, and execution time. Dev-only by default.
`@Once()`	The method runs at most once per instance; subsequent calls return the cached result.
`@Memo()`	Memoizes per unique argument set using a reactive `computed()` per cache entry.
`@Retry(n, options?)`	Retries an async method on failure with configurable delay and exponential backoff.

Rendering optimizations. → Full page

Decorator	What it does
`@Lazy(placeholder?)`	Defers rendering until the component enters the viewport via `IntersectionObserver`.

For large list virtualization, see VirtualList from @praxisjs/composables.

Instrumentation decorators — imported from @praxisjs/devtools. No-ops unless DevTools.init() has been called. → Full page

Decorator	What it does
`@Debug(options?)`	Exposes a `@State` field, getter, or method in the Signals/Timeline panels.
`@Trace()`	Instruments a component class to report render count, duration, and lifecycle events in the Components panel.

Decorator	What it does
`@Compose(Class, ...args)`	Mixes a `Composable` class into the component. Wires its reactive properties and hooks its lifecycle automatically.

→ See Composables for the full list of built-in composable classes. → See Creating Composables to build your own.