`useRemoteRowIdListener`

The useRemoteRowIdListener hook registers a listener function with the Relationships object that will be called whenever a remote Row Id in a Relationship changes.

useRemoteRowIdListener(
  relationshipId: IdOrNull,
  localRowId: IdOrNull,
  listener: RemoteRowIdListener,
  listenerDeps?: DependencyList,
  relationshipsOrRelationshipsId?: any,
): void

	Type	Description
`relationshipId`	`IdOrNull`	The `Id` of the `Relationship` to listen to, or `null` as a wildcard.
`localRowId`	`IdOrNull`	The `Id` of the local `Row` to listen to, or `null` as a wildcard.
`listener`	`RemoteRowIdListener`	The function that will be called whenever the remote `Row` `Id` changes.
`listenerDeps?`	`DependencyList`	An optional array of dependencies for the `listener` function, which, if any change, result in the re-registration of the listener. This parameter defaults to an empty array.
`relationshipsOrRelationshipsId?`	`any`	The `Relationships` object to register the listener with: omit for the default context `Relationships` object, provide an `Id` for a named context `Relationships` object, or provide an explicit reference.
returns	`void`	This has no return value.

This hook 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 useRemoteRowId hook).

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

Both, either, or neither of the relationshipId and localRowId parameters can be wildcarded with null. You can listen to a specific local Row in a specific Relationship, any local Row in a specific Relationship, a specific local Row in any Relationship, or any local Row in any Relationship.

Unlike the addRemoteRowIdListener method, which returns a listener Id and requires you to remove it manually, the useRemoteRowIdListener hook manages this lifecycle for you: when the listener changes (per its listenerDeps dependencies) or the component unmounts, the listener on the underlying Indexes object will be deleted.

Example

This example uses the useRemoteRowIdListener hook to create a listener that is scoped to a single component. When the component is unmounted, the listener is removed from the Relationships object.

const App = ({relationships}) => (
  <Provider relationships={relationships}>
    <Pane />
  </Provider>
);
const Pane = () => {
  useRemoteRowIdListener('petSpecies', 'cujo', () =>
    console.log('Remote Row Id changed'),
  );
  return <span>App</span>;
};

const store = createStore()
  .setTable('pets', {fido: {species: 'dog'}, cujo: {species: 'dog'}})
  .setTable('species', {wolf: {price: 10}, dog: {price: 5}});
const relationships = createRelationships(store);
relationships.setRelationshipDefinition(
  'petSpecies',
  'pets',
  'species',
  'species',
);

const app = document.createElement('div');
const root = ReactDOMClient.createRoot(app);
root.render(<App relationships={relationships} />);
console.log(relationships.getListenerStats().remoteRowId);
// -> 1

store.setCell('pets', 'cujo', 'species', 'wolf');
// -> 'Remote Row Id changed'

root.unmount();
console.log(relationships.getListenerStats().remoteRowId);
// -> 0