Subscriptions

You can define subscribers functions to be called whenever a cell value change.

const cellA = sheet.new(1);

// create subscriptions on any cell
const unsubscribe = cellA.subscribe((v) => {
  console.log({ v });
});

// later call `unsubscribe` to cancel the subscription
unsubscribe();

When using cells in Svelte files, you can use the $cell sugar to subscribe to a cell value for display. Note that there is a initial undefined value when using that sugar as the reactive subscription are initially output by the Svelte compiler as let $cell;.

Unlike Svelte, subscriptions are called in transactional batches, i.e. cells wait until all updates are propagated in the Sheet to dispatch notifications once to subscribers. This prevents stuttering.