watch()

Observes changes in the table. Whenever an entity is inserted, updated, or deleted, blinkDB calls the provided callback with all table entities.

watch() is much, much faster than manually retrieving items everytime you insert, update, or remove. It’s perfect for usage inside reactive components like React Hooks.

// Call `callback` whenever ALL entities change
await watch(userTable, (users) => {
  console.log("All users: ", users);
});
// Call `callback` whenever an item matching the filter changes
await watch(userTable, { where: { age: { lt: 3 } } }, (babies) => {
  console.log("All babies: ", babies);
});

Parameter	Description
table	The table created by createTable() .
filter	Optional. If present, callback will only be called when a changed item matches the filter.
callback	The function which will be called whenever an item is inserted/updated/deleted.

Stop observing changes

If you want to stop watching for changes, call the function returned by watch().

const stop = await watch(userTable, (users) => {
  console.log("All users: ", users);
});

// Stop watching changes
stop();