`addSliceRowIdsListener`

The addSliceRowIdsListener method registers a listener function with the Indexes object that will be called whenever the Row Ids in a Slice change.

addSliceRowIdsListener(
  indexId: IdOrNull,
  sliceId: IdOrNull,
  listener: SliceRowIdsListener,
): string

	Type	Description
`indexId`	`IdOrNull`	The `Id` of the `Index` to listen to, or `null` as a wildcard.
`sliceId`	`IdOrNull`	The `Id` of the `Slice` to listen to, or `null` as a wildcard.
`listener`	`SliceRowIdsListener`	The function that will be called whenever the `Row` `Ids` in the `Slice` change.
returns	`string`	A unique `Id` for the listener that can later be used to remove it.

You can either listen to a single Slice (by specifying the Index Id and Slice Id as the method's first two parameters), or changes to any Slice (by providing null wildcards).

Both, either, or neither of the indexId and sliceId parameters can be wildcarded with null. You can listen to a specific Slice in a specific Index, any Slice in a specific Index, a specific Slice in any Index, or any Slice in any Index.

The provided listener is a SliceRowIdsListener function, and will be called with a reference to the Indexes object, the Id of the Index, and the Id of the Slice that changed.

Examples

This example creates a Store, an Indexes object, and then registers a listener that responds to any changes to a specific Slice.

import {createIndexes, createStore} from 'tinybase';

const store = createStore().setTable('pets', {
  fido: {species: 'dog'},
  felix: {species: 'cat'},
  cujo: {species: 'dog'},
});

const indexes = createIndexes(store);
indexes.setIndexDefinition('bySpecies', 'pets', 'species');

const listenerId = indexes.addSliceRowIdsListener(
  'bySpecies',
  'dog',
  (indexes) => {
    console.log('Row Ids for dog slice in bySpecies index changed');
    console.log(indexes.getSliceRowIds('bySpecies', 'dog'));
  },
);

store.setRow('pets', 'toto', {species: 'dog'});
// -> 'Row Ids for dog slice in bySpecies index changed'
// -> ['fido', 'cujo', 'toto']

indexes.delListener(listenerId);

This example creates a Store, an Indexes object, and then registers a listener that responds to any changes to any Slice.

import {createIndexes, createStore} from 'tinybase';

const store = createStore().setTable('pets', {
  fido: {species: 'dog', color: 'brown'},
  felix: {species: 'cat', color: 'black'},
  cujo: {species: 'dog', color: 'black'},
});

const indexes = createIndexes(store)
  .setIndexDefinition('bySpecies', 'pets', 'species')
  .setIndexDefinition('byColor', 'pets', 'color');

const listenerId = indexes.addSliceRowIdsListener(
  null,
  null,
  (indexes, indexId, sliceId) => {
    console.log(
      `Row Ids for ${sliceId} slice in ${indexId} index changed`,
    );
    console.log(indexes.getSliceRowIds(indexId, sliceId));
  },
);

store.setRow('pets', 'toto', {species: 'dog', color: 'brown'});
// -> 'Row Ids for dog slice in bySpecies index changed'
// -> ['fido', 'cujo', 'toto']
// -> 'Row Ids for brown slice in byColor index changed'
// -> ['fido', 'toto']

indexes.delListener(listenerId);

Since

v1.0.0