Group channel event handler

Use GroupChannelHandler to receive group channel event callbacks — including group operations, profile changes, member info changes, membership requests, and multi-device sync.

For detailed group management features, see Manage a group channel.

Register and remove the handler

Kotlin

kotlin

// Register
NCEngine.addGroupChannelHandler("MY_GROUP_HANDLER", object : GroupChannelHandler {
    override fun onGroupOperation(event: GroupOperationEvent) { /* ... */ }
})

// Remove
NCEngine.removeGroupChannelHandler("MY_GROUP_HANDLER")

Java

Java

// Register
NCEngine.addGroupChannelHandler("MY_GROUP_HANDLER", new GroupChannelHandler() {
    @Override
    public void onGroupOperation(@NonNull GroupOperationEvent event) { /* ... */ }
});

// Remove
NCEngine.removeGroupChannelHandler("MY_GROUP_HANDLER");

tip

In managed group services, group operation SDK callbacks are also status notifications. Regardless of whether your app implements event listeners, the server syncs state to the SDK to keep local data current. These syncs count toward message distribution statistics.

Implement GroupChannelHandler

All methods have default empty implementations. Override only the callbacks you need.

Kotlin

kotlin

NCEngine.addGroupChannelHandler("MY_GROUP_HANDLER", object : GroupChannelHandler {

    // Group operation (create, join, leave, kick, dismiss, etc.)
    override fun onGroupOperation(event: GroupOperationEvent) {
        // event.groupId       — affected group ID
        // event.operation — GroupOperation type
        // event.operatorInfo  — operator's member info (null for server-side kicks)
        // event.groupInfo     — group info (non-null only on CREATE)
        // event.memberInfos   — involved members
        // event.operationTime — timestamp (ms)
        println("Group ${event.groupId} operation: ${event.operation}")
    }

    // Group profile changed
    override fun onGroupInfoChanged(event: GroupInfoChangedEvent) {
        // event.operatorInfo      — operator's member info
        // event.fullGroupInfo     — complete group info after change
        // event.changedProperties — list of changed property name strings
        // event.operationTime     — timestamp (ms)
        println("Changed properties: ${event.changedProperties}")
    }

    // Group member profile changed
    override fun onGroupMemberInfoChanged(event: GroupMemberInfoChangedEvent) {
        // event.groupId       — group ID
        // event.operatorInfo  — operator's member info
        // event.memberInfo    — updated member profile
        // event.operationTime — timestamp (ms)
        println("Member ${event.memberInfo.userId} updated in group ${event.groupId}")
    }

    // Group membership request (join requests, invitations, and their outcomes)
    override fun onGroupApplicationEvent(event: GroupApplicationEvent) {
        // event.groupId — group ID
        // event.type    — GroupApplicationType
        println("Group application: ${event.groupId}, type: ${event.type}")
    }

    // Group favorites multi-device sync
    override fun onGroupFavoritesChangedSync(event: GroupFavoritesChangedSyncEvent) {
        // event.groupId       — group ID
        // event.operation — GroupOperationType (ADD or REMOVE)
        // event.userIds       — affected user IDs
        // event.operationTime — timestamp (ms)
        println("Group favorites synced for group: ${event.groupId}")
    }
})

Java

Java

NCEngine.addGroupChannelHandler("MY_GROUP_HANDLER", new GroupChannelHandler() {

    // Group operation (create, join, leave, kick, dismiss, etc.)
    @Override
    public void onGroupOperation(@NonNull GroupOperationEvent event) {
        System.out.println("Group " + event.getGroupId() + " operation: " + event.getOperation());
    }

    // Group profile changed
    @Override
    public void onGroupInfoChanged(@NonNull GroupInfoChangedEvent event) {
        System.out.println("Changed properties: " + event.getChangedProperties());
    }

    // Group member profile changed
    @Override
    public void onGroupMemberInfoChanged(@NonNull GroupMemberInfoChangedEvent event) {
        System.out.println("Member updated in group: " + event.getGroupId());
    }

    // Group membership request
    @Override
    public void onGroupApplicationEvent(@NonNull GroupApplicationEvent event) {
        System.out.println("Group application: " + event.getGroupId());
    }

    // Group favorites multi-device sync
    @Override
    public void onGroupFavoritesChangedSync(@NonNull GroupFavoritesChangedSyncEvent event) {
        System.out.println("Group favorites synced: " + event.getGroupId());
    }
});

Callback reference

Callback	Parameter type	Trigger
onGroupOperation	GroupOperationEvent	A group operation occurred (create, join, leave, kick, dismiss, etc.).
onGroupInfoChanged	GroupInfoChangedEvent	Group profile was updated. Check changedProperties to see which fields changed.
onGroupMemberInfoChanged	GroupMemberInfoChangedEvent	A group member's profile was updated.
onGroupApplicationEvent	GroupApplicationEvent	A group join request or invitation changed status.
onGroupFavoritesChangedSync	GroupFavoritesChangedSyncEvent	Group favorites changed on another device (multi-device sync).

Related topics

• Manage group channels
• Manage group members
• Manage membership requests