Objective-C categories: Can I add a property for a method not in my category?

objective-c properties categories
Alex Wayne picture Alex Wayne · Mar 26, 2010 · Viewed 24.9k times · Source

I want to use a category to make a method on the original class available as a property as well.

Class A:

@interface ClassA
- (NSString*)foo;
@end

Class A category

@interface ClassA (Properties)
- (void)someCategoryMethod;
@property (nonatomic, readonly) NSString *foo;
@end

Now when I do this, it seems to work (EDIT: Maybe it doesn't work, it doesn't complain but I am seeing strangeness), but it gives me warnings because I am not synthesizing the property in my category implementation. How do I tell the compiler everything is actually just fine since the original class synthesizes the property for me?

Answer

codewarrior picture codewarrior · Mar 26, 2010

Here's the warning you're getting:

warning: property ‘foo’ requires method '-foo' to be defined - use @synthesize, @dynamic or provide a method implementation

To suppress this warning, have this in your implementation:

@dynamic foo;

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