JavaScript Offline Recovery & UniApp Migration

The JavaScript SDK has no built-in persistent message database. Your application server supplies data after page reload, during disconnected periods, and for history pagination.

Offline recovery

First implement the message synchronization provider:

sdk.config.provider.syncMessagesCallback = async (channel, options) => {
  const rows = await messageApi.sync({
    channelID: channel.channelID,
    channelType: channel.channelType,
    startMessageSeq: options.startMessageSeq,
    endMessageSeq: options.endMessageSeq,
    limit: Math.min(options.limit, 100),
    pullMode: options.pullMode,
  })
  return rows.map(toSDKMessage)
}

After reconnecting, continue from the last saved message sequence and deduplicate by messageID or by messageSeq within the channel:

const options = new SyncOptions()
options.startMessageSeq = lastMessageSeq
options.limit = 50
options.pullMode = PullMode.Up

const recovered = await sdk.chatManager.syncMessages(channel, options)
mergeMessages(recovered)

Keep the cursor when synchronization fails and allow retry. Do not advance it before messages are processed successfully.

Migrate from the old UniApp SDK

The official wukongimuniappsdk is no longer maintained. Do not add it to new projects. Migrate existing projects in this order:

npm uninstall wukongimuniappsdk
npm install --save-exact wukongimjssdk@1.3.5

Import from the package root, never from wukongimjssdk/lib/*:

import WKSDK, {
  Channel,
  ConnectStatus,
  MessageText,
} from 'wukongimjssdk'

Then migrate each integration point:

1. Set uid, token, WebSocket endpoint, and device type.
2. Reconnect message, conversation, and channel providers.
3. Register custom content before connecting.
4. Use addConnectStatusListener, addMessageListener, and addMessageStatusListener.
5. Send through chatManager.send(...).
6. Remove the same function references when components unmount.

UniApp runtime notes

Version 1.3.5 automatically selects global uni.connectSocket, wx.connectSocket, or native WebSocket. Do not force the choice through config.platform; in the current implementation that value does not initialize the socket factory, which can mix one creation path with another event API.

Set device type by target: a native app container is usually 0, H5/Web is 1, and desktop is 2. Choose a mini-program type from your product protocol rather than assuming based only on JavaScript.

App, H5, and every mini-program are different runtimes. Test WSS allowlists, certificates, foreground/background behavior, network switching, live messages, recovery, and deduplication separately. Success in one target does not establish success in another.