Lifecycle

setup, mount and unmount.

Order

  1. setup() runs once, before rendering.
  2. render() runs once and returns the DOM.
  3. The onMount callbacks run once the DOM is in the page.
  4. On unmount, the cleanup returned by onMount and the onUnmount callbacks run, then everything the component owns is disposed.

onMount()

Register it in setup(). It may return a cleanup function, which runs on unmount.

onUnmount()

protected setup(): void {
  const socket = new WebSocket(url);
  this.onUnmount(() => socket.close());
}

What you do not clean up

Bindings, effects created in setup(), control flow branches and child components are owned by the component and disposed for you. Only clean up what Signy cannot see, such as timers, sockets and listeners on window.