createWsSynchronizer

The createWsSynchronizer function creates a WsSynchronizer object that can synchronize MergeableStore data to and from other MergeableStore instances via WebSockets facilitated by a WsServer.

createWsSynchronizer<WebSocketType>(
  store: MergeableStore,
  webSocket: WebSocketType,
  requestTimeoutSeconds?: number,
  onSend?: Send,
  onReceive?: Receive,
  onIgnoredError?: (error: any) => void,
  fragmentSize?: number,
): Promise<WsSynchronizer<WebSocketType>>

As well as providing a reference to the MergeableStore to persist, you must provide a configured WebSocket to send synchronization messages over. The path in the WebSocket URL is used by a WsServer as the path that the client joins. The MergeableStore Id does not select the server path.

Instead of the raw browser implementation of WebSocket, you may prefer to use the Reconnecting WebSocket wrapper so that if a client goes offline, it can easily re-establish a connection when it comes back online. Its API is compatible with this Synchronizer.

You can indicate how long the Synchronizer will wait for responses to message requests before timing out. A final set of optional handlers can be provided to help debug sends, receives, and errors respectively.

This method is asynchronous because it will await the websocket's connection to the server. You will need to await a call to this function or handle the return type natively as a Promise.

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

const server = createWsServer(new WebSocketServer({port: 8047}));

const store1 = createMergeableStore();
const store2 = createMergeableStore();

const synchronizer1 = await createWsSynchronizer(
  store1,
  new WebSocket('ws://localhost:8047/petShop'),
);
const synchronizer2 = await createWsSynchronizer(
  store2,
  new WebSocket('ws://localhost:8047/petShop'),
);

await synchronizer1.startSync();
await synchronizer2.startSync();

store1.setTables({pets: {fido: {species: 'dog'}}});
store2.setTables({pets: {felix: {species: 'cat'}}});

// ...
console.log(store1.getTables());
// -> {pets: {fido: {species: 'dog'}, felix: {species: 'cat'}}}
console.log(store2.getTables());
// -> {pets: {fido: {species: 'dog'}, felix: {species: 'cat'}}}

await synchronizer1.destroy();
await synchronizer2.destroy();
await server.destroy();