`Indexes`

An Indexes object lets you look up all the Row objects in a Table that have a certain Cell value.

This is useful for creating filtered views of a Table, or simple search functionality.

Create an Indexes object easily with the createIndexes function. From there, you can add new Index definitions (with the setIndexDefinition method), query their contents (with the getSliceIds method and getSliceRowIds method), and add listeners for when they change (with the addSliceIdsListener method and addSliceRowIdsListener method).

This module defaults to indexing Row objects by one of their Cell values. However, far more complex indexes can be configured with a custom function.

Example

This example shows a very simple lifecycle of an Indexes object: from creation, to adding a definition, getting its contents, and then registering and removing a listener for it.

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

const indexes = createIndexes(store);
indexes.setIndexDefinition(
  'bySpecies', // indexId
  'pets', //      tableId to index
  'species', //   cellId to index
);

console.log(indexes.getSliceIds('bySpecies'));
// -> ['dog', 'cat']
console.log(indexes.getSliceRowIds('bySpecies', 'dog'));
// -> ['fido', 'cujo']

const listenerId = indexes.addSliceIdsListener('bySpecies', () => {
  console.log(indexes.getSliceIds('bySpecies'));
});
store.setRow('pets', 'lowly', {species: 'worm'});
// -> ['dog', 'cat', 'worm']

indexes.delListener(listenerId);
indexes.destroy();

Getter methods

This is the collection of getter methods within the Indexes interface. There are 7 getter methods in total.

Listener methods

This is the collection of listener methods within the Indexes interface. There are only three listener methods, addSliceRowIdsListener, addSliceIdsListener, and delListener.

Configuration methods

This is the collection of configuration methods within the Indexes interface. There are only two configuration methods, delIndexDefinition and setIndexDefinition.