TinyBase

addTableListener

The addTableListener method registers a listener function with the Store that will be called whenever data in a Table changes.

addTableListener(
  tableId: IdOrNull,
  listener: TableListener,
  mutator?: boolean,
): string
TypeDescription
tableIdIdOrNull

The Id of the Table to listen to, or null as a wildcard.

listenerTableListener

The function that will be called whenever data in the matching Table changes.

mutator?boolean

An optional boolean that indicates that the listener mutates Store data.

returnsstring

A unique Id for the listener that can later be used to call it explicitly, or to remove it.

You can either listen to a single Table (by specifying its Id as the method's first parameter) or changes to any Table (by providing a null wildcard).

The provided listener is a TableListener function, and will be called with a reference to the Store, the Id of the Table that changed, and a GetCellChange function in case you need to inspect any changes that occurred.

Use the optional mutator parameter to indicate that there is code in the listener that will mutate Store data. If set to false (or omitted), such mutations will be silently ignored. All relevant mutator listeners (with this flag set to true) are called before any non-mutator listeners (since the latter may become relevant due to changes made in the former). The changes made by mutator listeners do not fire other mutating listeners, though they will fire non-mutator listeners.

Examples

This example registers a listener that responds to any changes to a specific Table.

const store = createStore().setTables({
  pets: {fido: {species: 'dog', color: 'brown'}},
});
const listenerId = store.addTableListener(
  'pets',
  (store, tableId, getCellChange) => {
    console.log('pets table changed');
    console.log(getCellChange('pets', 'fido', 'color'));
  },
);

store.setCell('pets', 'fido', 'color', 'walnut');
// -> 'pets table changed'
// -> [true, 'brown', 'walnut']

store.delListener(listenerId);

This example registers a listener that responds to any changes to any Table.

const store = createStore().setTables({
  pets: {fido: {species: 'dog', color: 'brown'}},
});
const listenerId = store.addTableListener(null, (store, tableId) => {
  console.log(`${tableId} table changed`);
});

store.setCell('pets', 'fido', 'color', 'walnut');
// -> 'pets table changed'
store.setTable('species', {dog: {price: 5}});
// -> 'species table changed'

store.delListener(listenerId);

This example registers a listener that responds to any changes to a specific Table, and which also mutates the Store itself.

const store = createStore().setTables({
  pets: {fido: {species: 'dog', color: 'brown'}},
});
const listenerId = store.addTableListener(
  'pets',
  (store, tableId) => store.setCell('meta', 'update', tableId, true),
  true,
);

store.delCell('pets', 'fido', 'color');
console.log(store.getTable('meta'));
// -> {update: {pets: true}}

store.delListener(listenerId);