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useHasValues

The useHasValues primitive returns a boolean indicating whether any Values exist in the Store, and registers a listener so that any changes to that result will cause an update.

useHasValues(storeOrStoreId?: MaybeAccessor<undefined | StoreOrStoreId>): Accessor<boolean>
TypeDescription
storeOrStoreId?MaybeAccessor<undefined | StoreOrStoreId>

The Store to be accessed: omit for the default context Store, provide an Id for a named context Store, or provide an explicit reference.

returnsAccessor<boolean>

Whether any Values exist.

A Provider component is used to wrap part of an application in a context, and it can contain a default Store or a set of Store objects named by Id. The useHasValues primitive lets you indicate which Store to get data for: omit the optional parameter for the default context Store, provide an Id for a named context Store, or provide a Store explicitly by reference.

When first rendered, this primitive will create a listener so that changes to the Values will cause an update. When the component containing this primitive is unmounted, the listener will be automatically removed.

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 {useHasValues} 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');
  useHasValues(store);
  dispose();
});

Since

v8.3.0