Determine successful establishment of connection and broken connection via NSStream

Question

I'm trying to write something like wrapper for NSStream to make my life easier. I just want to know when is connection established, when is closed, write some data a get received data. So I'm thinking about something like this:

Header:

@interface StreamWrapper : NSObject

- (id)initWithDelegate:(id <StreamWrapperDelegate>)delegate;
- (void)writeData:(NSData *)data;

@end

@protocol StreamWrapperDelegate <NSObject>

@required
- (void)streamWrapper:(StreamWrapper *)streamWrapper didReceiveData:(NSData *)data;
- (void)streamWrapperDidConnect:(StreamWrapper *)streamWrapper;
- (void)streamWrapperDidCloseConnection:(StreamWrapper *)streamWrapper;

@end

Class:

@interface StreamWrapper () <NSStreamDelegate>

...
@property (nonatomic, weak) id <StreamWrapperDelegate> delegate;
@property (nonatomic, strong) NSInputStream *inputStream;
@property (nonatomic, strong) NSOutputStream *outputStream;

- (void)closeStreams;
- (void)setAndOpenStreams;

@end

@implementation StreamWrapper

#pragma mark - NSStreamDelegate

- (void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode
{
    switch (eventCode) {

        case NSStreamEventEndEncountered:
            // Should I here close both streams (even if this is called only for one (in or out)) and delegate closed connection?
            break;

        case NSStreamEventErrorOccurred:
            // Should I here close both streams (even if this is called only for one (in or out)) and delegate closed connection?
            break;

        case NSStreamEventHasBytesAvailable:
            // My reading algorithm... 
            [self.delegate streamWrapper:self didReceiveData:data];
            break;

        case NSStreamEventHasSpaceAvailable:
            // Is this useful for me?
            break;

        case NSStreamEventNone:
            // Is this useful for me?
            break;

        case NSStreamEventOpenCompleted:
            // Should I here delegate successful connection? Should I wait to receive this for both streams? How?
            break;

        default:
            break;
    }
}

...

@end

So... how to implement that I will always know when is connection established and I'm able to send and receive data and when is connection broken (even only one way) and I should close it and try for brand new establishment? Or what is proper way to do something like this?

Answer 1

According To Apple's Developer Website

 NSStreamEventNone
 No event has occurred.

 Available in OS X v10.3 and later.

 Declared in NSStream.h.

 NSStreamEventOpenCompleted
 The open has completed successfully.

 Available in OS X v10.3 and later.

 Declared in NSStream.h.

 NSStreamEventHasBytesAvailable
 The stream has bytes to be read.

  Available in OS X v10.3 and later.

 Declared in NSStream.h.

 NSStreamEventHasSpaceAvailable
 The stream can accept bytes for writing.

 Available in OS X v10.3 and later.

 Declared in NSStream.h.

 NSStreamEventErrorOccurred
 An error has occurred on the stream.

 Available in OS X v10.3 and later.

 Declared in NSStream.h.

 NSStreamEventEndEncountered
 The end of the stream has been reached.

 Available in OS X v10.3 and later.

 Declared in NSStream.h.

• also please refer to this articles for more information :

Article : Byte-available event

Article : space-available event

Answer 2

My previous experience with NSStream is to capture the first NSStreamEventHasSpaceAvailable event as the signal for connection establishment.

I also nil out the input and output streams when Error or Completed message arise - so I only need to check if these streams are nil in the writeData: method.