Accessing Method from other Classes Objective-C

Question

Looked for an answer for this question, but I haven\'t found a suitable one yet. I\'m hoping you guys (and gals) can help me out! (This is for an iPhone app)

Alrig

Answer 1

Another method that you can use

@interface ServerManager : NSObject

+(ServerManager *)getInstance;

@implementation ServerManager

+(ServerManager *)getInstance
{
static ServerManager *objServerManager = nil;

if(objServerManager==NULL){
objServerManager=[[self alloc] init];
}
// Return the servermanager object.
return objServerManager;
}

Call Whether you want to use

ServerManager *SMObject =   [ServerManager getInstance];

Don't forget to import servermanager.h file.

Answer 2

What you want to do is to make the two controllers share a common superclass:

UIViewController : MyAwesomeViewController : ViewController1
                                           : ViewController2

commonMethod: would then reside in MyAwesomeViewController. Also, don't start method names with capital letters. :)

To elaborate:

+@interface MyAwesomeController : UIViewController {

-@interface ViewController1 : UIViewController { // and ditto for ViewController2
+@interface ViewController1 : MyAwesomeController {

Answer 3

As an iPhone neophyte with a Java background and little C, I had a similar problem wishing to refer to a method in both the RootController and a ViewController. It seemed to me that the proper place for the method was the AppDelegate class, an instance of which one obtains in other classes by:

MyAppDelegate *delegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];

then if the method is "doSomething" one accesses it by:

[delegate doSomething];

But perhaps this is too obvious or not what was required.

Answer 4

There are some answers here telling you to create a common "parent" class. However I think that you can do a lot better. Create a category for UIViewController instead. You don't know all of the internals of what is going on with UIViewController so I don't think it is worth creating your own View Controller hierarchy off of. In fact it could be dangerous. I ran into a number of problems when I tried to create a "base" UITableViewController and then create classes that inherit from that. I avoided these problems by using categories instead.

Your #1 priority shouldn't be inheriting things for no good reason, it should be getting an app into the app store that people will want to download.

Answer 5

Pass in a reference to your commonClass when you alloc and init your views...

CommonClass *cc = [[CommonClass alloc] init];

ViewController1 *vc1 = [[ViewController1 alloc] ... initWith:cc];
ViewController2 *vc2 = [[ViewController2 alloc] ... initWith:cc];

but making a classic c include might suffice.

Answer 6

Option 1:

@implementation commonClass
+ (void)CommonMethod:(id)sender  /* note the + sign */
{
//So some awesome generic stuff...
    }
@end

@implementation ViewController2

- (void)do_something... {
    [commonClass CommonMethod];
}


@end

Option 2:

@implementation commonClass
- (void)CommonMethod:(id)sender
{
//So some awesome generic stuff...
    }
@end

@implementation ViewController2

- (void)do_something... {
    commonClass *c=[[commonClass alloc] init];
    [c CommonMethod];
    [c release];
}

@end

Option 3: use inheritance (see Mr. Totland's description in this thread)

@implementation commonClass
- (void)CommonMethod:(id)sender
{
//So some awesome generic stuff...
    }
@end

/* in your .h file */
@interface ViewController2: commonClass

@end

naturally you always need to #import commonClass.h in your view controllers..