`useValueListener`

The useValueListener primitive registers a listener function with a Store that will be called whenever data in a Value changes.

useValueListener(
  valueId: MaybeAccessor<IdOrNull>,
  listener: ValueListener,
  mutator?: boolean,
  storeOrStoreId?: MaybeAccessor<undefined | StoreOrStoreId>,
): void

	Type	Description
`valueId`	`MaybeAccessor<IdOrNull>`	The `Id` of the `Value` to listen to, or `null` as a wildcard.
`listener`	`ValueListener`	The function that will be called whenever data in the `Value` changes.
`mutator?`	`boolean`	An optional boolean that indicates that the listener mutates `Store` data.
`storeOrStoreId?`	`MaybeAccessor<undefined \| StoreOrStoreId>`	The `Store` to register the listener with: omit for the default context `Store`, provide an `Id` for a named context `Store`, or provide an explicit reference.
returns	`void`	This has no return value.

This primitive is useful for situations where a component needs to register its own specific listener to do more than simply tracking the value (which is more easily done with the useValue primitive).

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

Unlike the addValueListener method, which returns a listener Id and requires you to remove it manually, the useValueListener primitive manages this lifecycle for you: when the component unmounts, the listener on the underlying Store will be deleted.

Example

This example creates the TinyBase objects needed by the Solid primitive or component and calls it from within a reactive root.

import {createRoot} from 'solid-js';
import {
  createCheckpoints,
  createIndexes,
  createMetrics,
  createQueries,
  createRelationships,
  createStore,
} from 'tinybase';
import {useValueListener} from 'tinybase/ui-solid';

createRoot((dispose) => {
  const store = createStore()
    .setTables({
      pets: {
        fido: {species: 'dog', color: 'brown', next: 'felix'},
        felix: {species: 'cat', color: 'black'},
      },
      species: {dog: {price: 5}, cat: {price: 4}},
    })
    .setValues({open: true});
  const metrics = createMetrics(store).setMetricDefinition(
    'highestPrice',
    'species',
    'max',
    'price',
  );
  const indexes = createIndexes(store).setIndexDefinition(
    'bySpecies',
    'pets',
    'species',
  );
  const relationships = createRelationships(store)
    .setRelationshipDefinition('petSpecies', 'pets', 'species', 'species')
    .setRelationshipDefinition('nextPet', 'pets', 'pets', 'next');
  const queries = createQueries(store).setQueryDefinition(
    'petColors',
    'pets',
    ({select, where, param}) => {
      select('color');
      where((getCell) => getCell('species') == param('species'));
    },
    {species: 'dog'},
  );
  const checkpoints = createCheckpoints(store);
  store.setCell('pets', 'fido', 'color', 'walnut');
  checkpoints.setCheckpoint('updated color');
  metrics.getMetric('highestPrice');
  indexes.getSliceIds('bySpecies');
  relationships.getRemoteRowId('petSpecies', 'fido');
  queries.getResultRowIds('petColors');
  useValueListener('open', () => undefined, false, store);
  dispose();
});

Since

v8.3.0