Streaming messages

Streaming messages are generated by the server and delivered incrementally to the client SDK. The client receives a streaming message notification, then pulls the full content in chunks.

NCStreamMessage properties

Property	Type	Description
content	NSString	Streaming message content
type	NSString	Text format
isComplete	BOOL	Whether content generation is complete
completeReason	NSInteger	Abnormal termination reason (from app server)
stopReason	NSInteger	Termination reason (from IM server, 0 = normal)
sync	BOOL	Whether the client has finished pulling
referenceInfo	NCStreamReferenceInfo *	Reference information for the streaming message

tip

• The SDK cannot send streaming messages — they are server-initiated only.
• After receiving a streaming message, call requestStreamMessage (Objective-C: requestStreamMessageWithCompletion:) to pull the full content.

Receive streaming messages

Register an NCMessageHandler and implement onMessageReceived: to detect incoming streaming messages:

Swift

swift

import NexconnChatSDK
final class MyMessageHandler: NSObject, MessageHandler {
    func onMessageReceived(_ event: MessageReceivedEvent) {
        guard let message = event.message else { return }
        if let streamContent = message.content as? StreamMessage, !streamContent.sync {
            // Streaming message received — start pulling content
            pullStreamingContent(message)
        }
    }
}

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

Objective-C

Objective C

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

- (void)onMessageReceived:(NCMessageReceivedEvent *)event {
    NCMessage *message = event.message;
    if ([message.content isKindOfClass:[NCStreamMessage class]]) {
        // Streaming message received — start pulling content
        NCStreamMessage *streamContent = (NCStreamMessage *)message.content;
        if (!streamContent.sync) {
            [self pullStreamingContent:message];
        }
    }
}

Pull streaming message content

Implement streaming event callbacks

The NCMessageHandler protocol provides three methods for streaming events:

Swift

swift

import NexconnChatSDK
func onStreamMessageRequestInit(_ event: StreamMessageRequestInitEvent) {
    // event.messageId: the server message ID — pull initialized
}

func onStreamMessageRequestDelta(_ event: StreamMessageDeltaEvent) {
    // event.message: the message with the latest aggregated content
    // event.chunkInfo.content: the delta (incremental text for this event)
}

func onStreamMessageRequestComplete(_ event: StreamMessageRequestCompleteEvent) {
    if let error = event.error {
        print("Stream error: \(error.localizedDescription)")
    } else {
        // event.messageId: pull complete — message is fully received
    }
}

Objective-C

Objective C

- (void)onStreamMessageRequestInit:(NCStreamMessageRequestInitEvent *)event {
    // event.messageId: the server message ID — pull initialized
}

- (void)onStreamMessageRequestDelta:(NCStreamMessageDeltaEvent *)event {
    // event.message: the message with the latest aggregated content
    // event.chunkInfo.content: the delta (incremental text for this event)
}

- (void)onStreamMessageRequestComplete:(NCStreamMessageRequestCompleteEvent *)event {
    if (!event.error) {
        // event.messageId: pull complete — message is fully received
    } else {
        NSLog(@"Stream error: %@", event.error.localizedDescription);
    }
}

Start pulling

Call requestStreamMessageWithCompletion: on the received NCMessage instance. The method uses the server message ID (message.messageId) internally:

Swift

swift

import NexconnChatSDK
func pullStreamingContent(_ message: Message) {
    message.requestStreamMessage { error in
        if error == nil {
            // Pull request sent — await streaming callbacks
        }
    }
}

Objective-C

Objective C

- (void)pullStreamingContent:(NCMessage *)message {
    [message requestStreamMessageWithCompletion:^(NCError *error) {
        if (!error) {
            // Pull request sent — await streaming callbacks
        }
    }];
}

Streaming message summary

After the server finishes generating content, it may send a summary via message metadata. The metadata key is business-defined by your server implementation. Listen for metadata updates via NCMessageHandler:

Swift

swift

import NexconnChatSDK
func onMessageMetadataUpdated(_ event: MessageMetadataUpdatedEvent) {
    guard let message = event.message,
          message.content is StreamMessage else { return }
    let summary = event.metadata["summary"]
    if let summary {
        // Update UI with summary
    }
}

Objective-C

Objective C

- (void)onMessageMetadataUpdated:(NCMessageMetadataUpdatedEvent *)event {
    NCMessage *message = event.message;
    NSDictionary<NSString *, NSString *> *metadata = event.metadata;
    if ([message.content isKindOfClass:[NCStreamMessage class]]) {
        NSString *summary = metadata[@"summary"];
        if (summary) {
            // Update UI with summary
        }
    }
}