Objective-C Block Property with Xcode code completion

You can definitely have your cake and eat it too, if you are willing to add one extra line of code to your class interface.

First, define block with a typedef and create a property like you did in your question:

typedef void (^CompletionBlock)(MyObject *myObj);...@property (nonatomic, copy) CompletionBlock completionBlock;

Next, as MobileOverload pointed out in his answer, we know that Xcode provides correct code completion for typedef'd blocks if used in a standalone method declaration. So, let's add an explicit declaration for the setter of completionBlock:

- (void)setCompletionBlock:(CompletionBlock)completionBlock;

When called, this method resolves to the setter method declared by the property. However, because we explicitly defined it in the class interface, Xcode sees it and applies full code completion.

So, if you include all three of those lines you should get the desired result. This behavior is clearly a shortcoming of Xcode, as there is no reason why a setter defined in a @property statement should have different code completion than the same method defined on its own.

You can get some fancy looking code completion when passing your blocks as an argument to a method in your class. In the header file I typedef'd the block like this

typedef void (^MyCompletionBlock)(id obj1, id obj2);

Then I was able to use it as an argument to my method that I have also declared in this class header.

-(void)doThisWithBlock:(MyCompletionBlock)block;

In the m file I declared the method

-(void)doThisWithBlock:(MyCompletionBlock)block {    NSLog(@"Something");}

and when I went to call it I got fancy code completion like this.

Hopefully this answers your question.

Ok so I figured out a stopgap way of doing this that does't result in warnings / errors... and actually makes things easier to read / shorter to type, etc.

define a macro with our "abbreviation", and then use the full format in the property declaration like...

#define TINP NSString*(^)(NSString *typed, const char *raw)@interface ....@property (copy) NSString*(^termDidReadString)(NSString *typed, const char *raw);

subsequently.. you can then reference that "kind" of argument, etc like..

+ (void)addInputBlock:(TINP)termDidReadString;

and voilá... not only will your code be TINIER!! but code completion will work, like a charm...