Intercept messages

The current version recommends implementing message interception and secondary processing through event listening + send wrapping.

Recommended approach

1. Receiving-side interception (listening)

Use NCEngine.addMessageHandler(...) to listen for message received, deleted, modified, and other events. Your business layer decides whether and how to display them.

Kotlin

kotlin

private const val MESSAGE_HANDLER_ID = "app_message_interceptor"

NCEngine.addMessageHandler(
  MESSAGE_HANDLER_ID,
  object : MessageHandler {
    override fun onMessageReceived(event: MessageReceivedEvent) {
      val message = event.message
      // Business filtering / analytics / risk control
    }

    override fun onMessageDeleted(event: MessageDeletedEvent) {
      // Handle deleted messages
    }
  }
)

NCEngine.removeMessageHandler(MESSAGE_HANDLER_ID)

Java

Java

private static final String MESSAGE_HANDLER_ID = "app_message_interceptor";

NCEngine.addMessageHandler(
    MESSAGE_HANDLER_ID,
    new MessageHandler() {
        @Override
        public void onMessageReceived(MessageReceivedEvent event) {
            Message message = event.getMessage();
            // Business filtering / analytics / risk control
        }

        @Override
        public void onMessageDeleted(MessageDeletedEvent event) {
            // Handle deleted messages
        }
    });

NCEngine.removeMessageHandler(MESSAGE_HANDLER_ID);

2. Sending-side interception (pre-send processing)

Before calling NCChatUI.sendMessage / NCChatUI.sendMediaMessage, process in your business layer:

• Modify SendMessageParams / SendMediaMessageParams
• Add metadata
• Block sending if rules are triggered

Kotlin

kotlin

fun safeSend(identifier: ChannelIdentifier, params: SendMessageParams) {
  // Business validation before sending
  if (shouldBlock(params)) return

  NCChatUI.sendMessage(identifier, params) { message, error ->
    // Send result
  }
}

Java

Java

void safeSend(ChannelIdentifier identifier, SendMessageParams params) {
    // Business validation before sending
    if (shouldBlock(params)) return;

    NCChatUI.sendMessage(identifier, params, (message, error) -> {
        // Send result
    });
}

3. Local message insertion interception

If you need business messages that are "inserted and displayed locally only", construct InsertMessageItem in your business layer first, then call NCChatUI.insertMessages(...).

Kotlin

kotlin

NCChatUI.insertMessages(identifier, listOf(item)) { result, error ->
  // Local insertion result
}

Java

Java

NCChatUI.insertMessages(identifier, Collections.singletonList(item), (result, error) -> {
    // Local insertion result
});

Notes

• Use the public APIs provided by NCChatUI / NCEngine / BaseChannel.
• Use the message construction methods and callback patterns provided by the current SDK.