Profanity filter callback

By default, the message sender is not notified when a message is blocked by moderation. To notify senders when their messages are blocked due to moderation rules, enable the profanity filter callback service.

Messages may be blocked in the following scenarios:

• The text message content matches a built-in profanity word, preventing delivery to the recipient.
• The text message content matches a custom profanity word (block rule), preventing delivery to the recipient.
• A pre-messaging webhook rule blocks the message before delivery.

Set up the blocked message listener

Use NCEngine.addMessageHandler to register a message handler that listens for message block events. When a sent message is blocked, the SDK triggers the onMessageBlocked callback in MessageHandler.

Kotlin

kotlin

NCEngine.addMessageHandler("BLOCK_HANDLER", object : MessageHandler {
    override fun onMessageBlocked(event: MessageBlockedEvent) {
        val info = event.info
        println("Message blocked: ${info.messageId}")
        println("Channel: ${info.channelIdentifier}")
        println("Block reason: ${info.blockType}")
    }
})

Java

Java

NCEngine.addMessageHandler("BLOCK_HANDLER", new MessageHandler() {
    @Override
    public void onMessageBlocked(@NonNull MessageBlockedEvent event) {
        BlockedMessageInfo info = event.getInfo();
        Log.d("Block", "Message blocked: " + info.getMessageId());
        Log.d("Block", "Channel: " + info.getChannelIdentifier());
        Log.d("Block", "Block reason: " + info.getBlockType());
    }
});

BlockedMessageInfo properties

BlockedMessageInfo contains information about the blocked message:

Property	Type	Description
channelIdentifier	ChannelIdentifier	Channel identifier of the blocked message, containing channel type and channel ID.
messageId	String	Unique ID of the blocked message.
blockType	MessageBlockType	Reason the message was blocked. See MessageBlockType below.
extra	String?	Additional information about the blocked message.
sourceType	Int	Source type of the blocked message. 0: The original message triggered the block (default). 1: A message expansion triggered the block. 2: An edited message triggered the block.
sourceContent	String?	JSON string of the blocked message or expansion content. When sourceType is 1, this contains the expansion content. When sourceType is 2, this contains the edited message content. See sourceContent below.

MessageBlockType values

Enum value	Description
GLOBAL	Global profanity word: the message matched a built-in global profanity word.
CUSTOM	Custom profanity word: the message matched a custom profanity word.
THIRD_PARTY	Blocked by a pre-messaging webhook rule.

sourceContent values

• When sourceType is 0: sourceContent is empty.
• When sourceType is 1: sourceContent is the message expansion content, e.g., {"mid":"xxx-xxx-xxx-xxx","put":{"key":"profanity word"}}. mid is the notification message ID.
• When sourceType is 2: sourceContent is the edited message content, e.g., {"content":"text containing profanity"}.

Retrieve the original blocked message

After a message is blocked, use BaseChannel.getMessageById to retrieve the original message and update its send status:

Kotlin

kotlin

NCEngine.addMessageHandler("BLOCK_HANDLER", object : MessageHandler {
    override fun onMessageBlocked(event: MessageBlockedEvent) {
        val info = event.info
        BaseChannel.getMessageById(GetMessageByIdParams(messageId = info.messageId)) { message, error ->
            if (error == null && message != null) {
                message.sentStatus = SentStatus.FAILED
                // Update UI to show failed status
            }
        }
    }
})

Java

Java

NCEngine.addMessageHandler("BLOCK_HANDLER", new MessageHandler() {
    @Override
    public void onMessageBlocked(@NonNull MessageBlockedEvent event) {
        BlockedMessageInfo info = event.getInfo();
        BaseChannel.getMessageById(new GetMessageByIdParams(info.getMessageId()), (message, error) -> {
            if (error == null && message != null) {
                message.setSentStatus(SentStatus.FAILED);
                // Update UI to show failed status
            }
            return null;
        });
    }
});