Recall a message

After sending a message, you can delete it for all participants in the channel. The SDK provides two deletion methods with different scopes.

Delete a message for everyone

deleteMessageForAll deletes a message visibly for all clients. It is implemented internally as recall + delete. Call this method on the channel instance:

Swift

swift

import NexconnChatSDK
guard let channel = DirectChannel(channelId: "targetUserId") else { return }
channel.deleteMessageForAll(message) { deletedMessage, error in
    if let error {
        print("Delete failed: \(error.localizedDescription)")
    } else {
        // deletedMessage: the deleted message entity — update UI accordingly
    }
}

Objective-C

Objective C

NCDirectChannel *channel = [[NCDirectChannel alloc] initWithChannelId:@"targetUserId"];

[channel deleteMessageForAll:message
                  completion:^(NCMessage *deletedMessage, NCError *error) {
    if (error) {
        NSLog(@"Delete failed: %@", error.localizedDescription);
    } else {
        // deletedMessage: the deleted message entity — update UI accordingly
    }
}];

Delete messages (self only)

deleteMessagesForMe deletes messages for the current user on both remote and local — they become invisible to the current user across all devices, while remaining visible to other participants. Supports batch deletion (maximum 100 per call):

Swift

swift

import NexconnChatSDK
guard let channel = DirectChannel(channelId: "targetUserId") else { return }
channel.deleteMessagesForMe([message1, message2]) { error in
    if error == nil {
        // Deleted locally
    }
}

Objective-C

Objective C

[channel deleteMessagesForMe:@[message1, message2]
                  completion:^(NCError *error) {
    if (!error) {
        // Deleted locally
    }
}];

Delete local messages by client ID

To delete local messages without a channel reference, use deleteLocalMessages on NCBaseChannel:

Swift

swift

import NexconnChatSDK
BaseChannel.deleteLocalMessages(messageClientIds: [message.clientId]) { isDeleted, error in
    // isDeleted: true if at least one message was deleted
}

Objective-C

Objective C

[NCBaseChannel deleteLocalMessages:@[@(message.clientId)]
                        completion:^(BOOL isDeleted, NCError *error) {
    // isDeleted: YES if at least one message was deleted
}];

Listen for message deletion events

Register an NCMessageHandler to receive notifications when messages are deleted on other clients:

Swift

swift

import NexconnChatSDK
final class MyMessageHandler: NSObject, MessageHandler {
    func onMessageDeleted(_ event: MessageDeletedEvent) {
        // event.messages: the deleted messages — update UI accordingly
    }
}

let handler = MyMessageHandler()
NCEngine.addMessageHandler(identifier: "YourKey", handler: handler)

Objective-C

Objective C

[NCEngine addMessageHandlerWithIdentifier:@"YourKey" handler:self];

- (void)onMessageDeleted:(NCMessageDeletedEvent *)event {
    // event.messages: the deleted messages — update UI accordingly
}