Question

I’m making a simple program in Objective-C. It has one class with a lot of methods. I’d just like to put the methods in another file… so I could move the following

- (void) myfunc1 {...}
- (void) myfunc2 {...}
// more functions

to another file and replace the above w/ something like

#include "myNewFile.something"

I’m fine w/ putting the #include (or whatever) statement just right in the original file.

How can I do this?

Answer 1

You’ll need to split your methods in to different “categories,” which each get their own h and m files. You’ll also need an h and m file for the class itself. Here’s a simple little example that I think will show you what you need to do.

TestClass.h

#import <Cocoa/Cocoa.h>
@interface TestClass : NSObject {
}
@end

TestClass.m

#import "TestClass.h"
@implementation TestClass
@end

TestClass+Category1.h

#import <Cocoa/Cocoa.h>
#import "TestClass.h"
@interface TestClass(Category1) 
-(void)TestMethod1;
@end

TestClass+Category1.m

#import "TestClass+Category1.h"
@implementation TestClass(Category1)
-(void)TestMethod1 {
NSLog(@"This is the output from TestMethod1");
}
@end

TestClass+Category2.h

#import <Cocoa/Cocoa.h>
#import "TestClass.h"
@interface TestClass(Category2) 
-(void)TestMethod2;
@end

TestClass+Category2.m

#import "TestClass+Category2.h"
@implementation TestClass(Category2)
-(void)TestMethod2 {
NSLog(@"This is the output from TestMethod2");
}
@end

Then in whatever file is using your class, you’ll use

#import "TestClass.h"
#import "TestClass+Category1.h"
#import "TestClass+Category2.h"

Now you can create an instance of class TestClass and it will have all the methods from both category1 and category2. Simply use

TestClass* test = [[TestClass alloc] init];
[test TestMethod1];
[test TestMethod2];