//
//  SharedDBManager.h
//  ClassVarTest
//
//  Created by Ashok Menon on 26/05/2010.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//
 
#import <Cocoa/Cocoa.h>
 
 
@interface SharedDBManager : NSObject {
 
}
 
-(id)init;
-(void)instanceAddsRecord:(id)obj;
-(id)instanceReturnsObjectAtIndex:(NSUInteger)index;
-(int)instanceReturnsInstanceCount;
+(void)initializeSharedDB;
+(id)returnObjectAtIndex:(NSUInteger)index;
+(int)instanceCount;
+(void)addRecord:(id)obj;
-(void)dealloc;
+(void)purgeSharedDB;
+(void)reInitializeSharedDB;
 
@end
 
 
 
//
//  SharedDBManager.m
//  ClassVarTest
//
//  Created by Ashok Menon on 26/05/2010.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//
 
#import "SharedDBManager.h"
 
static NSMutableArray *SharedDB;
static int count;
 
@implementation SharedDBManager
 
-(id)init {
	if (self = [super init]) {
		count ++;
	}
	return self;
}
 
-(void)instanceAddsRecord:(id)obj {
	[SharedDBManager addRecord:obj];
}
 
-(id)instanceReturnsObjectAtIndex:(NSUInteger)index {
	return [SharedDBManager returnObjectAtIndex:index];
}
 
-(int)instanceReturnsInstanceCount {
	return count;
}
 
+(void)initializeSharedDB{
	SharedDB = [[NSMutableArray alloc] init];
	count = 0;
}
 
+(id)returnObjectAtIndex:(NSUInteger)index {
	return [SharedDB objectAtIndex:index];
}
 
+(int)instanceCount {
	return count;
}
 
+(void)addRecord:(id)obj {
	[SharedDB addObject:obj];
}
 
-(void)dealloc {
	count--;
	[super dealloc];
}
 
+(void)purgeSharedDB {
	SharedDB = nil;
}
 
+(void)reInitializeSharedDB {
	[SharedDBManager purgeSharedDB];
	SharedDB = [[NSMutableArray alloc] init];
}
 
@end
 
 
 
//
//  ClassOne.h
//  ClassVarTest
//
//  Created by Ashok Menon on 26/05/2010.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//
 
#import <Cocoa/Cocoa.h>
 
@class SharedDBManager;
 
@interface ClassOne : NSObject {
	SharedDBManager *dbManager;
}
 
@property (nonatomic, retain) SharedDBManager *dbManager;
 
-(id)init;
-(void)dealloc;
 
@end
 
 
 
//
//  ClassOne.m
//  ClassVarTest
//
//  Created by Ashok Menon on 26/05/2010.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//
 
#import "ClassOne.h"
#import "SharedDBManager.h"
 
@implementation ClassOne
 
@synthesize dbManager;
 
-(id)init {
	if (self = [super init]) {
		dbManager = [[SharedDBManager alloc] init];
 
		NSString *record = [NSString 
							stringWithFormat:@"Added from ClassOne"];
		[dbManager instanceAddsRecord:record];
		[record release];
	}
 
	return self;
}
 
-(void)dealloc {
	[dbManager release];
	[super dealloc];
}
@end
 
 
 
//
//  ClassOne.h
//  ClassVarTest
//
//  Created by Ashok Menon on 26/05/2010.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//
 
#import <Cocoa/Cocoa.h>
 
@class SharedDBManager;
 
@interface ClassTwo : NSObject {
	SharedDBManager *dbManager;
}
 
@property (nonatomic, retain) SharedDBManager *dbManager;
 
-(id)init;
-(void)dealloc;
 
@end
 
 
 
//
//  ClassOne.m
//  ClassVarTest
//
//  Created by Ashok Menon on 26/05/2010.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//
 
#import "ClassTwo.h"
#import "SharedDBManager.h"
 
@implementation ClassTwo
 
@synthesize dbManager;
 
-(id)init {
	if (self = [super init]) {
		dbManager = [[SharedDBManager alloc] init];
 
		NSString *record = [NSString 
							stringWithFormat:@"Added from ClassTwo"];
		[dbManager instanceAddsRecord:record];
		[record release];
	}
 
	return self;
}
 
-(void)dealloc {
	[dbManager release];
	[super dealloc];
}
@end
 
 
 
#import <Foundation/Foundation.h>
#import "SharedDBManager.h"
#import "ClassOne.h"
#import "ClassTwo.h"
 
int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
 
    [SharedDBManager initializeSharedDB];
 
	ClassOne *classA = [[ClassOne alloc] init];
	ClassTwo *classB = [[ClassTwo alloc] init];
 
	NSLog(@"Instances of SharedDB: %d", [SharedDBManager instanceCount]);
 
	NSLog(@"Object Created by ClassOne, Accessed by ClassOne: %@", [classA.dbManager instanceReturnsObjectAtIndex:0]);
	NSLog(@"Object Created by ClassTwo, Accessed by ClassTwo: %@", [classB.dbManager instanceReturnsObjectAtIndex:1]);
	NSLog(@"Object Created by ClassOne, Accessed by Class Two: %@", [classB.dbManager instanceReturnsObjectAtIndex:0]);
	NSLog(@"Object Created by ClassTwo, Accessed by Class One: %@", [classA.dbManager instanceReturnsObjectAtIndex:1]);
    NSLog(@"Object Created by ClassOne, Accessed by SharedDBManager: %@", [SharedDBManager returnObjectAtIndex:0]);
	NSLog(@"Object Created by ClassTwo, Accessed by SharedDBManager: %@", [SharedDBManager returnObjectAtIndex:1]);
 
	[SharedDBManager reInitializeSharedDB];
 
	[SharedDBManager addRecord:@"First Record, Created by SharedDBManager"];
 
	NSLog(@"Object Created by SharedDBManager, Accessed by Class One: %@", [classA.dbManager instanceReturnsObjectAtIndex:0]);
 
	[classA release];
	[classB release];
	NSLog(@"Instance Count: %d", [SharedDBManager instanceCount]);
	[pool drain];
    return 0;
}