Same Protocol defined in multiple class

Question

Is it possible to define a same protocol with different methods in different classes?

Ex: In classA.h

  @protocol ME_DELEGATE <NSObject>

  @required

  -(void)doThis;

  @end

In classB.h

@protocol ME_DELEGATE <NSObject>

@required

-(void)doThat;

@end

Am I doing it right?

Why would you do this? Why not have two protocols with two different names? — rmaddy
– rmaddy, Commented Apr 7, 2014 at 23:03
I'm creating a static library where each class (5 NSObject classes totally) has its own delegate protocols. When I integrate into project I just want to add one protocol to call all the methods in different classes. — Siddharthan Asokan
– Siddharthan Asokan, Commented Apr 7, 2014 at 23:05
As @aguiarpgc said, put all of the delegate methods in one protocol and make them optional. Gotta agree with rmaddy though and say that it sounds like a much better design would have multiple protocols, each with the appropriate methods defined. — David Berry
– David Berry, Commented Apr 7, 2014 at 23:11
I see so is there a way that I can call multiple protocol through a single import instead? — Siddharthan Asokan
– Siddharthan Asokan, Commented Apr 7, 2014 at 23:15

eharo2 · Accepted Answer · 2014-04-08 00:02:37Z

@Siddharthan Asokan

You can have the same protocol in two different classes and the system will generate a warning "Duplicate protocol definition of 'protocolName' is ignored" (with the default settings)

You can make it work if you declare the protocol methods as @required or @optional.

Also, If you want to have 2 different objects being the delegates for the same protocol, then as already suggested, you need to have the protocol methods defined as @optional... I have tested and it works.... The trickier part is to get the reference to the objects to set the second delegate properly

I added an exercise to show how it works both ways.... Same protocol in two classes and then 2 different objects being the delegates of the same protocol. It also shows how to have 2 delegates to the same class, in the same protocol.

https://github.com/eharo2/ProtocolTest

Given that the protocols are based in the message passing paradigm, with the proper object reference and method implementation, you can do pretty much what you want.

I hope it helps... e

Collectives™ on Stack Overflow

Same Protocol defined in multiple class

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related