Global Property in Objective C

Question

I have an enum defined in the Constants.h file this way:

typedef enum {
    CalendarTypeMonth = 0,
    CalendarTypeWeek
} CalendarType;

Then in my view controller I determine what the calendar type should be and store it in a property this way:

@property (nonatomic) CalendarType myCalendarType;

Now I want all the classes in my project have access to the calendar type. How can I set this property to be global/extern so that all classes can read this?

EDIT: I know the definition of the enum will be available across the project. But what I am interested in is the value of myCalendarType . How can I access the value of myCalendarType across all classes?

Answer 1

You can declare class method to access static variable.

Add such code to your implementation file:

static MyStaticType staticVar = MyStaticTypeDefault;

+(BOOL)myStaticVar
{
    return staticVar;
}

+(void)setMyStaticVar:(MyStaticType)newValue
{
    staticVar = newValue;
}

And create declarations for this methods in interface file. This is much better then moving all static values to AppDelegate. Anyway, a lot of variants are possible - for example, you can create singletone to store some settings of application or use CoreData.

Answer 2

In your [Project Name]_Prefix.pch file, you can add this statement:

#import "Constants.h"

In so doing, you'll make your enum available to every file in the project.

EDIT: To access the value, I suggest making it a global property of your application delegate. To take it a step further, you can make your application delegate a method of NSObject using a category so it might look something like:

CalendarType current = [self appDelegate].currentCalendarType

Observe that your property is now a globally gettable/settable property.