= [super initWithFrame:CGRectZero]; 4 if (self) { 5 // Build objects... 6 RAC(backButton, enabled) = RACObserve(self, backEnabled); 7 RAC(forwardButton, enabled) = RACObserve(self, forwardEnabled); 8 RAC(titleLabel, text) = RACObserve(self, title); 9 10 RACSignal *loadingSignal = RACObserve(self, loading); 11 RAC(refreshButton, hidden) = loadingSignal; 12 RAC(stopButton, hidden) = [loadingSignal map:^id(NSNumber *enabled) { 13 return [NSNumber numberWithBool:![enabled boolValue]]; 14 }]; 15 } 16 return self; 17 } !10