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addPathIdsListener

The addPathIdsListener method registers a listener function with the WsServer that will be called whenever there is a change in the active paths that a WsServer is handling.

addPathIdsListener(listener: PathIdsListener): string
TypeDescription
listenerPathIdsListener

The function that will be called whenever the path Ids handled by the WsServer change.

returnsstring

A unique Id for the listener that can later be used to remove it.

The provided listener is a PathIdsListener function, and will be called with a reference to the WsServer and a callback you can use to get information about the change.

Example

This example creates a WsServer, and listens to changes to the active paths when clients connect to and disconnect from it.

import {WebSocket, WebSocketServer} from 'ws';
import {createMergeableStore} from 'tinybase';
import {createWsServer} from 'tinybase/synchronizers/synchronizer-ws-server';
import {createWsSynchronizer} from 'tinybase/synchronizers/synchronizer-ws-client';

const server = createWsServer(new WebSocketServer({port: 8047}));
const listenerId = server.addPathIdsListener(
  (server, pathId, addedOrRemoved) => {
    console.log(pathId + (addedOrRemoved == 1 ? ' added' : ' removed'));
    console.log(server.getPathIds());
  },
);

const synchronizer1 = await createWsSynchronizer(
  createMergeableStore(),
  new WebSocket('ws://localhost:8047/roomA'),
);
// -> 'roomA added'
// -> ['roomA']

const synchronizer2 = await createWsSynchronizer(
  createMergeableStore(),
  new WebSocket('ws://localhost:8047/roomB'),
);
// -> 'roomB added'
// -> ['roomA', 'roomB']

synchronizer1.destroy();
// ...
// -> 'roomA removed'
// -> ['roomB']

synchronizer2.destroy();
// ...
// -> 'roomB removed'
// -> []

server.delListener(listenerId);
server.destroy();

Since

v5.0.0