Owners and Cleanup

Use owner when a model is created at runtime and must later detach the work it created.

This is common for modals, chats, document tabs, media players, timers, and subscriptions to browser APIs. The risk is not the store value itself. The risk is the work around it: reactions, intervals, external listeners, in-flight effects, and cleanup callbacks.

Put Runtime Work Under An Owner

An owner gives dynamic work one lifetime. Anything created inside the owner can be disposed together.

import { event, onCleanup, owner, reaction, store } from "@virentia/core";

export function createDraftModel() {
  return owner(() => {
    const changed = event<string>();
    const text = store("");

    reaction({
      on: changed,
      run(value) {
        text.value = value;
      },
    });

    return { changed, text };
  });
}

owner adds dispose() to the model root. When the draft is closed, call dispose. The reactions created inside the owner are detached with it.

const draft = createDraftModel();

draft.dispose();

If your runtime supports using and Symbol.dispose, cleanup can be tied to a block:

{
  using draft = createDraftModel();

  // use draft
}

WARNING

Symbol.dispose and using are not equally available in every JavaScript runtime, including Safari without transpilation. If your runtime, bundler, or transpiler does not support them, use plain model.dispose().

Register External Cleanup

Use onCleanup for work that Virentia cannot know about by itself.

const timerModel = owner(() => {
  const timer = setInterval(() => {}, 1000);

  onCleanup(() => {
    clearInterval(timer);
  });

  return {};
});

Use withOwner when a helper needs to attach cleanup to an owner that already exists. This keeps helper code reusable without making it responsible for the whole model lifetime.

Owners are not only about avoiding leaks. They make lifecycle decisions visible: this model is temporary, this work belongs to it, and this is the point where it is allowed to disappear.