Event<T>

A subscribable event, modeled on VS Code's Event<T> convention: call it with a listener and get back a Disposable that cancels the subscription. It's the shared shape for one-off, payload-carrying notifications across the SDK (the first being ctx.editors.onDidSave).

import type { Event } from "@silo-code/sdk";

Shape

type Event<T> = (listener: (e: T) => void) => Disposable;

A service exposes an event as a member typed Event<T>. You call it directly with a listener; push the returned disposable onto ctx.subscriptions so it's cleaned up when your extension deactivates.

Example

export function activate(ctx: ExtensionContext) {
  ctx.subscriptions.push(
    ctx.editors.onDidSave(({ editorId, filePath }) => {
      ctx.log.info(`saved ${filePath}`);
    }),
  );
}

Notes

• Extensions never create emitters. The matching emitter (EventEmitter<T>) lives in the extension host; only the subscribable Event<T> face is public. You consume events, you don't fire them.
• Distinct from reactive state. For "current value that changes over time" (active editor, workspace list, theme) use a service's getState() / subscribe() with useServiceState. Event<T> is for discrete occurrences (a save happened), not observable state.
• Distinct from the provider subscribe*/invalidate* pattern. Those broadcast "re-query your provider" with no payload; an Event<T> delivers a typed payload describing what happened.

Types

Event

See also

ctx.editors.onDidSave · Roadmap