Protocol of delegate or source class, which is defined first ?

Discussion in 'iOS Programming' started by namanhams, Jun 18, 2009.

  1. namanhams macrumors regular

    Joined:
    Jun 3, 2009
    #1
    Hi everyone,

    I've used delegate many times, but i've just realized something that i dont know why it can be like that.
    Let say a class A has a delegate which implements a protocol B.

    - Class A :
    @interface A : NSObject {
    id<B> delegate;
    }
    @end

    - Protocol B :
    @protocol B
    - object : (A *) a doSomething : (SomeClass *) s
    @end

    Because A references B, B references A, I dont know how can i define both things. I know it's possible (the UITableView and UITableViewDelegate is an example), but i dont know how. I've tried to go arround this problem but the compiler keeps giving me errors.

    Thanks for reading my post.
     
  2. kainjow Moderator emeritus

    kainjow

    Joined:
    Jun 15, 2000
    #2
    Before the @interface on your class, put @protocol B; - this just makes the compiler aware of the protocol at that point, similar to how you can use @class.
     
  3. namanhams thread starter macrumors regular

    Joined:
    Jun 3, 2009
    #3
    I know about @class, but i dont know that we can use @protocol the same way.

    Thanks a lot.
     

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