Question

I am new to Cocoa/iOS – iphone platform

I am trying to work with network streams using Core Foundations. I am following the CFNetworking guide but I can’t get a simple test to work. The following compiles and runs but nothing is recorded to NSLog.

I am providing the Callback, clientCB, to CFReadStreamSetClient and scheduling the readStream on the run loop (at least that’s the idea).

I was expecting the CallBack to report something.

Can someone tell me where I am going wrong? I have telnet’d to this server and it works. Any suggestions would be helpful.

Thanks.

void clientCB(CFReadStreamRef stream, CFStreamEventType event, void *myPtr)
{
    switch(event) {
        case kCFStreamEventHasBytesAvailable:{
            UInt8 buf[BUFSIZE];
            CFIndex bytesRead = CFReadStreamRead(stream, buf, BUFSIZE);
            if (bytesRead > 0) {
              NSLog(@"Server has data to read!");
            }
            break;
        }
        case kCFStreamEventErrorOccurred:
            NSLog(@"A Read Stream Error Has Occurred!");
        case kCFStreamEventEndEncountered:
            NSLog(@"A Read Stream Event End!");
        default:
            break;
    }

}



- (IBAction) connectToServer: (id) sender

{
    CFReadStreamRef readStream; 
    CFWriteStreamRef writeStream;
    CFHostRef host = CFHostCreateWithName(kCFAllocatorDefault, (CFStringRef)@"irc.freenode.net");
    CFStreamCreatePairWithSocketToCFHost(kCFAllocatorDefault, host, 6667, &readStream, &writeStream);

    CFStreamClientContext myContext = {
        0,
        self,
        (void *(*)(void *info))CFRetain,
        (void (*)(void *info))CFRelease,
        (CFStringRef (*)(void *info))CFCopyDescription
    };

    CFOptionFlags registeredEvents = kCFStreamEventHasBytesAvailable |
                                kCFStreamEventErrorOccurred | kCFStreamEventEndEncountered;

    if(CFReadStreamSetClient(readStream, registeredEvents, clientCB, &myContext))
    {
        CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
    }

}

Answer 1

It seems that you forgot to call CFReadStreamOpen.

    if(CFReadStreamSetClient(readStream, registeredEvents, clientCB, &myContext))
    {
        CFReadStreamScheduleWithRunLoop(readStream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
    }

    if (!CFReadStreamOpen(readStream)) {
        /* error handling */
    }
}