`useResultRowCountListener`

The useResultRowCountListener primitive registers a listener function with a Queries object that will be called whenever the count of ResultRow objects in a ResultTable changes.

useResultRowCountListener(
  queryId: MaybeAccessor<IdOrNull>,
  listener: ResultRowCountListener,
  queriesOrQueriesId?: MaybeAccessor<undefined | QueriesOrQueriesId>,
): void

	Type	Description
`queryId`	`MaybeAccessor<IdOrNull>`	The `Id` of the query to listen to, or `null` as a wildcard.
`listener`	`ResultRowCountListener`	The function that will be called whenever the `Row` `Ids` in the matching `ResultTable` change.
`queriesOrQueriesId?`	`MaybeAccessor<undefined \| QueriesOrQueriesId>`	The `Queries` object to register the listener with: omit for the default context `Queries` object, provide an `Id` for a named context `Queries` object, 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 useResultRowCount primitive).

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

Unlike the addResultRowCountListener method, which returns a listener Id and requires you to remove it manually, the useResultRowCountListener primitive manages this lifecycle for you: when the component unmounts, the listener on the underlying Queries object 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 {useResultRowCountListener} 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');
  useResultRowCountListener('petColors', () => undefined, queries);
  dispose();
});

Since

v8.3.0