How to handle Objective-C protocols that contain properties?

Question

I\'ve seen usage of Objective-C protocols get used in a fashion such as the following:

@protocol MyProtocol 

@required

@property (readonly)         


        

Answer 1

Take a look at my article PROPERTY IN PROTOCOL

Suppose I have MyProtocol that declares a name property, and MyClass that conforms to this protocol

Things worth noted

1. The identifier property in MyClass declares and generates getter, setter and backing _identifier variable
2. The name property only declares that MyClass has a getter, setter in the header. It does not generate getter, setter implementation and backing variable.

3. I can’t redeclare this name property, as it already declared by the protocol. Do this will yell an error

   @interface MyClass () // Class extension
   
   @property (nonatomic, strong) NSString *name;
   
   @end
   

How to use property in protocol

So to use MyClass with that name property, we have to do either

1. Declare the property again (AppDelegate.h does this way)

   @interface MyClass : NSObject 
   
   @property (nonatomic, strong) NSString *name;
   
   @property (nonatomic, strong) NSString *identifier;
   
   @end
   

2. Synthesize ourself

   @implementation MyClass
   
   @synthesize name;
   
   @end