gistfile1.m

- (RACSignal *)rac_capturedMetadataObjectsSignal
{
	[self setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
	RACSignal *signal = objc_getAssociatedObject(self, _cmd);
	if (signal != nil) return signal;
	
	signal = [[[[self rac_signalForSelector:@selector(captureOutput:didOutputMetadataObjects:fromConnection:) fromProtocol:@protocol(AVCaptureMetadataOutputObjectsDelegate)] reduceEach:^id(AVCaptureOutput * output, NSArray * objects, AVCaptureConnection * connection){
		return objects;
	}] filter:^BOOL(NSArray * objects) {
		return objects.count;
	}] map:^id(NSArray * objects) {
		return objects.firstObject;
	}];
	objc_setAssociatedObject(self, _cmd, signal, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
	return signal;
}