Event handlers overview

The Nexconn Chat SDK delivers real-time events through handler interfaces. Each interface covers a specific domain. You register handlers via NCEngine with a unique identifier string, which lets you add multiple independent listeners for the same event type and remove them individually.

How it works

All handler interfaces follow the same pattern:

1. Register — call the appropriate NCEngine.addXxxHandler(identifier, handler) method before you need events.
2. Implement — implement only the callbacks you care about. All interface methods have default empty implementations.
3. Remove — call NCEngine.removeXxxHandler(identifier) when the handler is no longer needed.

kotlin

// Register
NCEngine.addGroupChannelHandler("MY_HANDLER", object : GroupChannelHandler {
    override fun onGroupOperation(event: GroupOperationEventInfo) {
        println("Group ${event.groupId} operation: ${event.operationType}")
    }
})

// Remove
NCEngine.removeGroupChannelHandler("MY_HANDLER")

Most callbacks deliver an event object that carries all the relevant data. Read the details through its properties.

Available handler interfaces

Interface	Register/Remove method prefix	What it covers
GroupChannelHandler	addGroupChannelHandler	Group operations, profile changes, member changes, join requests, favorites sync
OpenChannelHandler	addOpenChannelHandler	Open channel enter/exit lifecycle, metadata, members, mute/ban
ChannelHandler	addChannelHandler	Channel list sync, pinned/DND/translate settings, typing status, community sub-channel events
UserHandler	addUserHandler	Subscription events, friend add/delete/apply/clear
UserSettingsHandler	addUserSettingsHandler	User-level settings sync completed
MessageHandler	addMessageHandler	Message receive, delete, modify, read receipts, stream messages, metadata
TagHandler	addTagHandler	Tag and channel-tag changes (multi-device sync)
TranslateHandler	addTranslateHandler	Translation language changes and auto-translate state
DatabaseStatusHandler	addDatabaseStatusHandler	Database schema upgrade lifecycle
ConnectionStatusHandler	addConnectionStatusHandler	SDK connection status changes