Accessing NSMutableDictionary Across Classes

Question

I have declared an NSMutableDictionary object in AppController.h and initialized in the corresponding AppController.m file.

AppController.h

 #import <Cocoa/Cocoa.h>


 @interface AppController : NSObject {

      NSMutableDictionary *uberDict;

 }

AppController.m

#import "AppController.h"


@implementation AppController


- (id)init
{
 uberDict = [NSMutableDictionary new];

 return self;
}

Now I want to use the NSMutableDictionary object in another view, flashcardView. I add/remove items in the dictionary using methods in the AppController class and want to use the same dictionary (with the current items still present in it) in the flashcardView view. The problem is that I don't know how to access the dictionary object from outside AppController. How would I do that?

from flashcardView.m

- (void)setAndCheckString
{
 NSArray *keys = [uberDict allKeys];
 NSString *i;
 for (i in keys) {
  string = i;
  NSLog(@"%@", string);
 }
}

Here's where the problem lies. What do I do with uberDict to make this work? Thanks!

Answer 1

While I encourage you to look at alternative design patterns, to do what you're looking for you simply need to add a method (or property) to access uberDict to AppController. As a property, the code would be:

@interface AppController : NSObject {
     NSMutableDictionary *uberDict;
}

@property (readonly) NSMutableArray *uberDict;
@end

in the AppController.h file, and just add a one line @synthesize uberDict; inside the AppContoller implementation (before the @end). Don't worry about the (readonly) -- this means that the object getting the uberDict cannot set it to a new dictionary, but still can modify the contents of the dict and read from it.