helpers.h

#define XStr(...) [NSString stringWithFormat:__VA_ARGS__]
#define XLog(...) NSLog(@"[%@:%@:%d] %@", kName, [NSString stringWithUTF8String:__FILE__], __LINE__, XStr(__VA_ARGS__))
#define XEq(a, b) (a != nil && b != nil && [a isEqualToString:b])
#define XIsEmpty(a) (a == nil || [a length] == 0)
#define XAlertBtnHandler(title, h) [UIAlertAction actionWithTitle:title style:UIAlertActionStyleDefault handler:h]
#define XAlertBtn(title) XAlertBtnHandler(title, nil)
#define XAlertTitle(title, msg) [UIAlertController alertControllerWithTitle:title message:msg preferredStyle:UIAlertControllerStyleAlert]
#define XAlert(msg) XAlertTitle(kName, msg)
#define XUrl(url) [[UIApplication sharedApplication] openURL:[NSURL URLWithString:url] options:@{} completionHandler:nil]
#define XStrDefault(val, def) (val == nil || ![val isKindOfClass:NSString.class] || ((NSString *)val).length == 0 ? def : val)