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Short hand for [[UIApplication sharedApplication] delegate]?

I stored global variables in my AppDelegate and access them by:

AppDelegate *d = [[UIApplication sharedApplication] delegate];
d.someString = ...

What's the recommend way to save some typing and so I don't need to AppDelegate *d = [[UIApplication sharedApplication] delegate]; again and again? Thanks!

like image 267
ohho Avatar asked Nov 10 '10 03:11

ohho


4 Answers

As Shaggy Frog said, define a macro in your YourAppDelegate.h file, an example like this:

#define AppDelegate (YourAppDelegate *)[[UIApplication sharedApplication] delegate]

Then you can get the app delegate in your code like this:

[AppDelegate ......];
like image 119
Nevin Avatar answered Nov 11 '22 02:11

Nevin


Since your app delegate never really changes, you can create an external that you define in the app delegate code, very similar to the NSApp external for Mac OS X Cocoa applications.

So, define the external in your AppDelegate header (or something else that you would include everywhere):

extern AppDelegate* appDelegate;

Then create it and set it in your implementation file:

AppDelegate* appDelegate = nil;

// later -- i can't recall the actual method name, but you get the idea
- (BOOL)applicationDidFinishLaunchingWithOptions:(NSDictionary*)options
{
  appDelegate = self;
  // do other stuff
  return YES;
}

Then other classes can just access it:

#import "AppDelegate.h"

// later
- (void)doSomethingGreat
{
  NSDictionary* mySettings = [appDelegate settings];
  if( [[mySettings objectForKey:@"stupidOptionSet"] boolValue] ) {
    // do something stupid
  }
}
like image 41
Jason Coco Avatar answered Nov 11 '22 03:11

Jason Coco


You could just create a C-style macro and put it in a header file somewhere.

(As for using your app delegate as a giant global variable catch-all, that's another rant for another day.)

like image 8
Shaggy Frog Avatar answered Nov 11 '22 02:11

Shaggy Frog


I create a category called UIApplication+delegate with some convenience messages in it. Getting my specific delegate being one of the convenience messages. So, for instance, if my app delegate was called MyAppDelegate, it would look like this:

UIApplication+delegate.h

#import "MyAppDelegate.h"

@interface UIApplication(delegate)
+ (MyAppDelegate *)thisApp;
@end

and UIApplication+delegate.m

#import "UIApplication+delegate.h"


@implementation UIApplication(delegate)

+ (MyAppDelegate *)thisApp {
    return (MyAppDelegate*)[[UIApplication sharedApplication] delegate];
}

@end

In a class that needs the delegate, I do this:

#import "UIApplication+delegate.h"

...

- (void)doStuff {
    MyAppDelegate *app = [UIApplication thisApp];
    // use "app"
}
like image 4
Daniel Avatar answered Nov 11 '22 01:11

Daniel