Question

I seem to be having a bit of trouble with using classes from other files in my interface. The way I have written it so far is…

#import "NodeBase.h"

@interface Node : NSObject {
@public
     Node * testnode;
}

where NodeBase is a header file that deals with the importing of the other classes i.e.

#import <Foundation/Foundation.h>

#import "Node.h"
#import "NodeConnection.h"
#import "NodeProperty.h"

The error I am getting is a “Parse Issue: Expected a type”, is there no way to use a class in this context? Or have I got the syntax completely wrong?

Answer 1

Your NodeBase.h imports Node.h, and your Node.h imports NodeBase.h, creating a circular reference. This is not allowed.

You can put everything in the Node.h

#import <Foundation/Foundation.h>
#import "NodeConnection.h"
#import "NodeProperty.h"

@interface Node : NSObject {
@public
     Node * testnode;
}

Then you can simply import Node.h in places where you need to reference Node*.

If you would like to hide common imports (e.g. <Foundation/Foundation.h>), you can put them into SupportingFile/<Your-Project-Name>.pch file.