cannot change AVCaptureConnection orientation - iphone

Question

I want to change the video orientation from front camera,
So I choose the previewLayer.orientation,and it indeed work .
Since the method is deprecated from IOS6 and I get a warning to use previewLayer.connection.videoOrientation
but I cannot access the connection property from previewLayer
- (void)addDeviceInput {
[session beginConfiguration];
[session removeInput:videoInput];
[self setVideoInput:nil];
AVCaptureDeviceInput *newDeviceInput = [[AVCaptureDeviceInput alloc] initWithDevice:[self frontFacingCamera] error:nil];
if ([session canAddInput:newDeviceInput]) {
[session addInput:newDeviceInput];
[self setVideoInput:newDeviceInput];
}
newDeviceInput = nil;
if (previewLayer) {
[previewLayer removeFromSuperlayer];
[previewLayer release];
previewLayer = nil;
}
[session commitConfiguration];
}
- (id)setupCameraSession {
if (!(self = [super init])) {
return nil;
}
self.frameRate = 0;
session = [[AVCaptureSession alloc] init];
[session beginConfiguration];
[session setSessionPreset:AVCaptureSessionPreset352x288];
[self addDeviceInput]; //invoke previous method
AVCaptureVideoDataOutput * newVideoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
newVideoDataOutput.videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:kCVPixelFormatType_32BGRA],
kCVPixelBufferPixelFormatTypeKey,nil];
newVideoDataOutput.alwaysDiscardsLateVideoFrames = YES;
if ([session canAddOutput:newVideoDataOutput]) {
[session addOutput:newVideoDataOutput];
[self setVideoOutput:newVideoDataOutput];
}
[newVideoDataOutput release];
self.frameRate = VIDEO_FRAME_RATE;
[session commitConfiguration];
AVCaptureVideoPreviewLayer * newPreviewLayer =
[[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
//[newPreviewLayer setSession:session]; //it doesn't work? and get error
[self setPreviewLayer:newPreviewLayer];
[newPreviewLayer release];
[session startRunning];
return self;
}
I get the error
error: Execution was interrupted, reason: Attempted to dereference an invalid ObjC Object or send it an unrecognized selector.