@interface ViewController : UIViewController { NSString *newTitle; } @property (strong, nonatomic) NSString *newTitle;
I'm currently using the iOS 5 SDK trying to develop my app. I'm trying to make an NSString a property, and then to synthesize it in the .m file (I have done this before with no issues). Now, I came across this: "Semantic Issue: Property's synthesized getter follows Cocoa naming convention for returning 'owned' objects."@synthesize newTitle;
answer:
You take ownership of an object if you create it using a method whose name begins with “alloc”, “new”, “copy”, or “mutableCopy”.
A property named
newTitle
, when synthesised, yields a method called-newTitle
, hence the warning/error.-newTitle
is supposed to be a getter method for thenewTitle
property, however naming conventions state that a method whose name begins withnew
returns an object that’s owned by the caller, which is not the case of getter methods.You can solve this by:
Renaming that property:
@property (strong, nonatomic) NSString *theNewTitle;
Keeping the property name and specifying a getter name that doesn’t begin with one of the special method name prefixes:
@property (strong, nonatomic, getter=theNewTitle) NSString *newTitle;
Keeping both the property name and the getter name, and telling the compiler that, even though the getter name starts with
new
, it belongs to thenone
method family as opposed to thenew
method family:#ifndef __has_attribute #define __has_attribute(x) 0 // Compatibility with non-clang compilers #endif #if __has_attribute(objc_method_family) #define BV_OBJC_METHOD_FAMILY_NONE __attribute__((objc_method_family(none))) #else #define BV_OBJC_METHOD_FAMILY_NONE #endif @interface ViewController : UIViewController @property (strong, nonatomic) NSString *newTitle; - (NSString *)newTitle BV_OBJC_METHOD_FAMILY_NONE; @end
Note that even though this solution allows you to keep
newTitle
as both the property name and the getter name, having a method called-newTitle
that doesn’t return an object owned by the caller can be confusing for other people reading your code.