`useCheckpoint`

The useCheckpoint primitive returns the label for a checkpoint, and registers a listener so that any changes to that result will cause an update.

useCheckpoint(
  checkpointId: MaybeAccessor<string>,
  checkpointsOrCheckpointsId?: MaybeAccessor<undefined | CheckpointsOrCheckpointsId>,
): Accessor<string | undefined>

Type Description

	Type	Description
`checkpointId`	`MaybeAccessor<string>`	The `Id` of the checkpoint.
`checkpointsOrCheckpointsId?`	`MaybeAccessor<undefined \| CheckpointsOrCheckpointsId>`	The `Checkpoints` object to be accessed: omit for the default context `Checkpoints` object, provide an `Id` for a named context `Checkpoints` object, or provide an explicit reference.
returns	`Accessor<string \| undefined>`	A string label for the requested checkpoint, an empty string if it was never set, or `undefined` if the checkpoint does not exist.

checkpointId

MaybeAccessor<string>

The Id of the checkpoint.

checkpointsOrCheckpointsId?

MaybeAccessor<undefined | CheckpointsOrCheckpointsId>

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

returns

Accessor<string | undefined>

A string label for the requested checkpoint, an empty string if it was never set, or undefined if the checkpoint does not exist.

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

When first rendered, this primitive will create a listener so that changes to the label 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 {useCheckpoint} 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');
  useCheckpoint('0', checkpoints);
  dispose();
});

Since

v8.3.0